A method of cooling tempered glass

Abstract

This invention relates to the field of tempered glass manufacturing and discloses a cooling method for tempered glass, comprising the following steps: S1. Placing the thermoformed tempered glass on a conveying mechanism and transporting it using the conveying rollers of the conveying mechanism; S2. Performing a approaching stage: driving the cooling mechanism to move along the conveying mechanism, controlling the moving direction of the cooling mechanism to be opposite to the conveying direction of the conveying mechanism; S31. Performing a follow-up cooling stage; S32. While performing step S31, controlling the inner side of the cooling mechanism to send air to the surface of the tempered glass, the airflow force gradually increasing from the inlet end of the cooling mechanism along the conveying path to a maximum set value; S4. After air cooling treatment, the conveying mechanism transports the tempered glass to a water cooling tank for water cooling and shaping; by controlling the cooling mechanism and the conveying mechanism to move in opposite directions, the principle of relative velocity superposition is used to achieve rapid approaching, effectively overcoming the defects of slow traditional unidirectional approaching and positioning and short effective heat exchange window.

Description

Technical Field

[0001] This invention relates to the field of tempered glass manufacturing, and more particularly to a method for cooling tempered glass. Background Technology

[0002] In the production of tempered glass, rapid and uniform cooling (i.e., quenching) after thermoforming is a core process that determines its surface compressive stress distribution, flatness, impact resistance, and optical quality. With the increasing demand for large-size and ultra-large-area tempered glass (typically ≥3m²) in fields such as building curtain walls, rail transportation, new energy, and special equipment, the demand for such glass is growing. 2 With the continued growth in demand, traditional cooling processes are increasingly revealing significant technical bottlenecks in handling the continuous and high-efficiency production of large-scale glass. Currently, the industry commonly employs fixed air grate cooling or static conveyor belt pressure equalization air cooling. Fixed air grates are typically arranged above and below the glass conveyor path, using multiple rows of nozzles to spray high-pressure air onto the uniformly moving or stationary glass surface to achieve rapid overall heat exchange. Some production lines have also attempted to introduce movable cooling mechanisms, using position sensors to track the glass's entry status and initiate unidirectional follow-up cooling. However, in actual industrial production of large-scale tempered glass, the aforementioned existing technologies have the following significant drawbacks: Large glass sheets have high heat capacity and thermal inertia, with significant differences in heat dissipation paths between the center and edge areas. Fixed air ducts with uniform pressure distribution struggle to match the actual thermal field, leading to uneven cooling rates and easily causing surface stress gradient imbalances. This can result in glass cracking, excessive roller conduit ripples, or optical distortions (such as rainbow spots or stress spots). Fixed cooling systems require the entire glass sheet to be fully within the air duct area before effective cooling can begin, resulting in a short actual heat exchange window. Traditional mobile cooling mechanisms often use unidirectional, uniform approach speeds, which are slow initially, occupying significant production line downtime and extending the overall cooling cycle. This makes it difficult to meet the demands of high-speed, continuous production of large-size glass. Traditional cooling logic is often designed around individual sheet processes, neglecting the dynamic matching of fluctuations in the spacing between adjacent glass sheets, the cooling mechanism's reset cycle, and the conveyor's transport cycle in large glass production lines. This results in high equipment idle rates, significant energy waste, and production line downtime due to mechanism reset delays or collision risks, making stable and reliable continuous automated operation difficult. Summary of the Invention

[0003] The purpose of this invention is to provide a cooling method for tempered glass to solve the above-mentioned problems. This method is adaptable to continuous production of large-scale tempered glass, achieves rapid and accurate approach, optimizes surface heat field distribution through dynamic gradient airflow, effectively suppresses thermal stress concentration, and improves cooling efficiency and production line synergy. The specific technical solution is as follows: A method for cooling tempered glass includes the following steps: S1. The thermoformed tempered glass is placed on the conveying mechanism and transported using the conveying rollers of the conveying mechanism; S2. Approaching Phase: Drive the cooling mechanism to move along the conveying mechanism, and control the moving direction of the cooling mechanism to be opposite to the conveying direction of the conveying mechanism, so that the cooling mechanism approaches the tempered glass; S31. Perform follow-up cooling stage: When the front end of the tempered glass enters the inner cavity of the cooling mechanism, switch the moving direction of the cooling mechanism to be the same as the conveying direction of the conveying mechanism, and control the displacement speed of the cooling mechanism to be less than the conveying speed of the conveying mechanism. S32. While S31 is being executed, the inner side of the cooling mechanism is controlled to send air to the surface of the tempered glass. The airflow force gradually increases from the inlet end of the cooling mechanism along the conveying path to the maximum set value, and the maximum set value is maintained until the outlet end of the cooling mechanism. S4. After air cooling, the conveying mechanism transports the tempered glass to a water cooling tank for water cooling and shaping.

[0004] As an improvement to the above technical solution, in S4, the adjustment of the air supply force is achieved by the coordinated control of several independent air supply units and air volume regulating valves arranged in an array along the length of the cooling mechanism. The output air pressure of each air supply unit increases according to a preset gradient, which is one of linear increase, logarithmic increase or step increase.

[0005] As an improvement to the above technical solution, in S2, the moving speed of the cooling mechanism in the approaching stage is 1.5-3.0 times the conveying speed of the conveying mechanism; in S3, the cooling mechanism has a position detection element for detecting the position of the tempered glass.

[0006] As an improvement to the above technical solution, in S3, during the follow-up cooling stage, the displacement speed of the cooling mechanism is 0.3-0.7 times the conveying speed of the conveying mechanism, and the relative speed difference between the conveying mechanism and the cooling mechanism is kept constant through the servo control system.

[0007] As an improvement to the above technical solution, S32 is followed by S33: after the tempered glass is sent out from the outlet of the cooling mechanism, the air supply force is controlled to gradually decrease to 10%-30% of the initial air force according to a preset attenuation curve, and then the air supply is stopped, and the cooling mechanism is reset or enters standby state.

[0008] As an improvement to the above technical solution, in S4, the water-cooling shaping includes immersing the air-cooled tempered glass in a circulating cooling medium with a temperature controlled at 18-30°C at a constant linear velocity, with an immersion time of 3-8 seconds, and the circulating cooling medium maintaining a constant temperature through an external heat exchange system.

[0009] As an improvement to the above technical solution, the air outlets of the inner air supply system of the cooling mechanism are arranged at the relative positions of the upper and lower surfaces of the tempered glass, and in S32, the air supply force of the corresponding air outlets on the upper and lower surfaces is symmetrically gradient distributed.

[0010] The beneficial effects of this invention are as follows: By controlling the reverse movement of the cooling mechanism and the conveying mechanism, rapid approach is achieved using the principle of relative velocity superposition, effectively overcoming the shortcomings of traditional unidirectional approach positioning, which is slow and has a short effective heat exchange window. This design enables the cooling mechanism to quickly position itself during the high-temperature plasticity period of glass, shortening the cooling start-up delay and adapting to the high-cycle continuous production requirements of large tempered glass. The airflow gradually increases from the inlet of the cooling mechanism along the conveying path to the maximum set value and is maintained until the outlet, breaking the traditional constant strong airflow or sudden start-stop mode. This gradient control allows the glass surface temperature to drop smoothly to the stress forming critical zone before the main body is quenched, effectively eliminating the thermal stress concentration points and microcrack initiation conditions caused by sudden cooling at the inlet, significantly reducing the glass breakage rate, while ensuring the uniform distribution of surface compressive stress and reducing stress spots and optical distortion; Once the front end of the glass enters the cavity, the cooling mechanism switches to operate in the same direction and at a low speed as the conveying mechanism. This design avoids the risk of rigid collisions that may result from reverse movement, and dynamically extends the time of wind action through a constant relative speed difference, making the cooling trajectory highly matched with the glass conveying path, thereby improving the controllability of cooling depth and flatness.

[0011] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the structure of the present invention.

[0014] In the diagram: 1. Conveying mechanism; 2. Cooling mechanism; 21. Air supply unit; 22. Detection element. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0016] The present invention aims to overcome the shortcomings of existing large-scale tempered glass cooling processes, such as low approach efficiency, sudden air supply changes that easily lead to thermal stress concentration and cracking, and poor coordination of multiple continuous operations. It provides a tempered glass cooling method that can achieve rapid and accurate approach, dynamic gradient uniform cooling, and is adapted to the continuous and efficient cycle of the production line.

[0017] Please see Figure 1 This invention discloses a cooling method for tempered glass, used in a continuous quenching production line for large-scale tempered glass. This method achieves efficient and uniform cooling of thermoformed glass through dynamic motion control and gradient airflow coordination, specifically including the following steps: S1. Establishment of conveying reference: The thermoformed tempered glass is placed on the conveying mechanism 1, which consists of multiple conveying rollers arranged side by side, and the glass is transported in a straight line by the conveying rollers.

[0018] S2. Reverse Approach Stage: The cooling mechanism 2 is driven to move linearly along the conveying mechanism 1, and its movement direction is controlled to be opposite to the conveying direction of the conveying mechanism 1. Utilizing the principle of relative velocity superposition, the cooling mechanism 2 quickly approaches the tempered glass. It is understandable that after thermoformed glass exits the kiln, effective heat exchange needs to be initiated within a very short time. Traditional unidirectional approach mechanisms, because they move in the same direction as the glass, have a relative velocity that is only the difference between the two, severely compressing the effective cooling window. This solution uses reverse motion, making the relative approach velocity equal to the sum of the two velocities, significantly shortening the mechanism's positioning time and seizing the golden cooling period during the high-temperature plasticization stage of the glass.

[0019] S31. Same-direction follow-up switching: When the front end of the tempered glass enters the inner cavity of the cooling mechanism 2, the moving direction of the cooling mechanism 2 is switched in real time to keep it consistent with the conveying direction of the conveying mechanism 1, and the displacement speed of the cooling mechanism 2 is controlled to be less than the conveying speed of the conveying mechanism 1, so as to form a stable same-direction follow-up state.

[0020] S32. Gradient Airflow Quenching: Simultaneously with step S31, the airflow system inside the cooling mechanism 2 is activated to supply air to the upper and lower surfaces of the tempered glass. The airflow force is controlled to gradually increase from the inlet end of the cooling mechanism 2 along the conveying path to the maximum set value, and maintained at the maximum set value until the outlet end of the cooling mechanism 2 during the glass body's passage through the cooling zone. Specifically, the surface temperature of thermoformed glass typically reaches 600℃-650℃. If the maximum airflow force is applied directly at the inlet, the surface will experience sudden cooling due to the large instantaneous temperature difference, resulting in thermal stress concentration points, which can easily lead to glass cracking or deepening of roller marks. By adopting an airflow curve that gradually increases from the inlet to a constant value in the middle and then maintains it at the outlet, the glass surface temperature gradually decreases to the stress forming critical zone before the main body is quenched, effectively suppressing thermal shock and ensuring the uniformity of surface compressive stress distribution and optical flatness.

[0021] S4. Water-cooled shaping connection: After the above-mentioned air-cooling treatment, the conveying mechanism 1 continues to transport the tempered glass, which has completed the main quenching, forward, allowing it to smoothly slide into the water-cooling tank for final water-cooling shaping. It can be understood that air cooling is mainly responsible for generating the main compressive stress on the glass surface, but considerable residual heat remains inside. The water-cooling tank, as the final cooling process, utilizes the high specific heat capacity and convective heat transfer coefficient of water to quickly lock in residual stress, achieving a composite cooling step and avoiding stress rebound or deformation caused by single-medium cooling.

[0022] Traditional air cooling systems often employ a continuous ventilation cavity, where the air pressure distribution is easily affected by the resistance along the duct, resulting in uneven distribution with high pressure at the inlet, low pressure in the middle, and low pressure at the outlet. To address this, the present invention provides an embodiment where, in step S32, the airflow force is controlled collaboratively by several independent air supply units 21 arranged in an array along the length of the cooling mechanism 2 and their connected airflow regulating valves. The output air pressure of each independent air supply unit 21 is independently adjusted by the central control system according to a preset gradient curve, causing the airflow force acting on the tempered glass surface to gradually increase from the inlet end of the cooling mechanism 2 along the conveying path to the maximum set value, and maintaining this set value until the outlet end. The preset gradient curve can be configured as a linear increase, a logarithmic increase, or a step-like increase according to process requirements. In this embodiment, independent air supply units 21 are arranged in sections along the length of the cooling mechanism 2, which essentially discretizes the continuous cooling zone into multiple independently adjustable heat exchange micro-zones. When the tempered glass passes through at a constant speed driven by the conveying mechanism 1, its surface successively passes through a low wind pressure zone, a gradually increasing wind pressure zone, and a constant high wind pressure zone. The spatial wind pressure gradient is automatically converted into a time-series cooling curve experienced by the glass, achieving dynamic matching.

[0023] Preferably, the inner air supply system of the cooling mechanism 2 is provided with an upper and lower opposing air supply array, with its air supply outlets respectively facing the upper and lower surfaces of the tempered glass at relative positions; and the air supply force of the air outlets at corresponding positions on the upper and lower surfaces strictly follows the symmetrical gradient distribution law, that is, at the same longitudinal section, the air pressure and air volume output by the upper and lower air outlets are kept synchronized in real time and change synchronously along the glass conveying path according to the same preset gradient curve.

[0024] Process adaptation criteria for the three gradient curves: Linear increase: The air pressure increases uniformly with position, suitable for architectural tempered glass of conventional thickness (6-12mm), providing a stable and predictable cooling rate, and simple process adjustment; Logarithmic increase: The wind pressure rises rapidly in the early stage and then the rate of increase slows down, which is in line with the thermodynamic law that the glass surface temperature decreases exponentially. It can quickly enter the high-efficiency heat exchange zone while avoiding the thermal shock at the inlet. It is especially suitable for special glass with large thickness (≥15mm) or low expansion coefficient. Step-by-step increment: The continuous gradient is discretized into several fixed wind pressure steps, which facilitates rapid response and fault-tolerant control through standard valve position combinations. It has strong resistance to sensor noise and is suitable for continuous production lines with high cycle time and large fluctuations in operating conditions.

[0025] In step S2, the moving speed of the cooling mechanism 2 in the approach phase is controlled to be 1.5-3.0 times the conveying speed of the conveying mechanism 1; in step S3, the inlet frame or side wall of the cooling mechanism 2 is integrated with a position detection element 22, which is used to collect the displacement signal of the front end of the tempered glass relative to the inlet of the cooling mechanism 2 in real time, and use the signal as the trigger reference for switching the follow-up cooling phase and starting the air supply system.

[0026] In this embodiment, the position detection element 22 (such as a laser ranging module, a through-beam photoelectric switch, or a magnetic encoder) is directly integrated onto the moving cooling mechanism 2 body, so that the detection reference is rigidly synchronized with the mechanism entrance. At this time, the sensor directly captures the relative displacement between the glass front end and the mechanism entrance, without the need for coordinate conversion, and can accurately determine the critical point of the glass front end entering the cavity, providing a millisecond-level synchronous trigger reference for the direction switching, speed reduction, and wind-driven start-up in stage S3.

[0027] In step S3, during the follow-up cooling stage, the displacement speed of the cooling mechanism 2 is controlled to be 0.3-0.7 times the conveying speed of the conveying mechanism 1; at the same time, the conveying mechanism 1 and the cooling mechanism 2 establish dynamic linkage control through the servo control system, so that the relative speed difference between the two remains constant throughout the cooling process.

[0028] Regarding the conveying speed of conveying mechanism 1, if the speed of cooling mechanism 2 is too low (relative speed difference is too large), the glass will quickly pass through the cooling zone, resulting in insufficient airflow time at a single point, insufficient surface compressive stress generation, and a tendency for low tempering or delayed cooling in the middle. If the speed of cooling mechanism 2 is too high (relative speed difference is too small), the relative sliding between the glass and the mechanism will slow down, and the front end will easily remain in the high air pressure zone for a long time, causing overcooling. The rear end will not be sufficiently cooled due to the incomplete establishment of the airflow field, resulting in unbalanced stress distribution and optical distortion. Therefore, this embodiment limits the conveying speed of conveying mechanism 1 to a certain range, which can ensure that each point on the glass surface receives sufficient air-cooling residence time (usually 3-8 seconds) and maintain a stable airflow shear layer, avoiding eddy current shearing or air pressure stagnation, and achieving a dynamic balance between cooling depth and production line cycle time.

[0029] Following step S32, step S33 is also included: when the position detection signal confirms that the tail of the tempered glass is completely detached from the outlet of the cooling mechanism 2, the control system initiates the wind force attenuation program, driving the air supply system to gradually reduce the output wind force to 10%-30% of the initial reference wind force according to the preset attenuation curve, and then completely cuts off the air supply; after the air supply stops, the cooling mechanism 2 performs a reset action to return to the initial approach position, or switches to a low-power standby state. After the wind stops, the cooling mechanism 2 automatically selects a path according to the arrival rhythm of the next piece of glass: if the production line interval is sufficient, it performs a full-stroke reset to the initial position to store energy for the next reverse approach; if the rhythm is tight, it switches to servo hold / low-power standby mode to shorten the idle response time. This logic dynamically couples the equipment operation cycle with the conveying rhythm of the conveying mechanism 1, eliminating production line downtime caused by equipment idling or reset conflicts.

[0030] In step S4, the water-cooling shaping specifically includes: immersing the tempered glass, which has undergone main air-cooling treatment, into a circulating cooling medium with a temperature controlled at 18-30°C at a constant linear velocity, with the immersion time precisely controlled to be 3-8 seconds; the circulating cooling medium is monitored and dynamically adjusted in real time by an external heat exchange system to maintain its operating temperature. It is understandable that when tempered glass transitions from the air-cooled zone to the water-cooled zone, fluctuations in the immersion velocity will cause inconsistencies in the unsteady heat transfer time experienced by different sections of the glass at the liquid-gas interface, easily leading to watermarks or localized stress gradients. Constant linear velocity immersion ensures that the cooling process of any micro-element on the glass surface as it crosses the liquid surface is completely reproduced, eliminating the stress distribution dispersion caused by velocity disturbances and ensuring the overall stress uniformity and optical consistency of the plate.

[0031] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for cooling tempered glass, characterized in that, Includes the following steps: S1. The thermoformed tempered glass is placed on the conveying mechanism and transported using the conveying rollers of the conveying mechanism; S2. Approaching Phase: Drive the cooling mechanism to move along the conveying mechanism, and control the moving direction of the cooling mechanism to be opposite to the conveying direction of the conveying mechanism, so that the cooling mechanism approaches the tempered glass; S31. Perform follow-up cooling stage: When the front end of the tempered glass enters the inner cavity of the cooling mechanism, switch the moving direction of the cooling mechanism to be the same as the conveying direction of the conveying mechanism, and control the displacement speed of the cooling mechanism to be less than the conveying speed of the conveying mechanism. S32. While S31 is being executed, the inner side of the cooling mechanism is controlled to send air to the surface of the tempered glass. The airflow force gradually increases from the inlet end of the cooling mechanism along the conveying path to the maximum set value, and the maximum set value is maintained until the outlet end of the cooling mechanism. S4. After air cooling, the conveying mechanism transports the tempered glass to a water cooling tank for water cooling and shaping.

2. The cooling method for tempered glass according to claim 1, characterized in that: In S4, the adjustment of the air supply force is achieved through the coordinated control of several independent air supply units and air volume regulating valves arranged in an array along the length of the cooling mechanism. The output air pressure of each air supply unit increases according to a preset gradient, which is one of linear increase, logarithmic increase or step increase.

3. The cooling method for tempered glass according to claim 1, characterized in that: In S2, the moving speed of the cooling mechanism in the approach phase is 1.5-3.0 times the conveying speed of the conveying mechanism; in S3, the cooling mechanism has a position detection element for detecting the position of the tempered glass.

4. The cooling method for tempered glass according to claim 1, characterized in that: In S3, during the follow-up cooling stage, the displacement speed of the cooling mechanism is 0.3-0.7 times the conveying speed of the conveying mechanism, and the relative speed difference between the conveying mechanism and the cooling mechanism is kept constant through the servo control system.

5. The cooling method for tempered glass according to claim 1, characterized in that: S32 is followed by S33: after the tempered glass is sent out from the outlet of the cooling mechanism, the air supply force is controlled to gradually decrease to 10%-30% of the initial air force according to a preset attenuation curve, and then the air supply is stopped, and the cooling mechanism is reset or enters standby state.

6. The cooling method for tempered glass according to claim 1, characterized in that: In step S4, the water-cooling shaping includes immersing the air-cooled tempered glass in a circulating cooling medium with a temperature controlled at 18-30°C at a constant linear velocity, with an immersion time of 3-8 seconds, and the circulating cooling medium maintaining a constant temperature through an external heat exchange system.

7. The cooling method for tempered glass according to claim 1, characterized in that: The air outlets of the inner air supply system of the cooling mechanism are arranged at the relative positions of the upper and lower surfaces of the tempered glass, and in S32, the air supply force of the corresponding air outlets on the upper and lower surfaces is symmetrically gradient distributed.

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