Float method on-line coating hot end real-time quality detection device

Abstract

The application discloses a kind of float method online coating hot end real-time quality detection device, the device adopts single-side cantilever type insertion structure, including hanging support mechanism, optical detection mechanism, transmission moving mechanism, cooling protection mechanism, sound-light alarm mechanism and temperature compensation mechanism, will be with spectral measurement element, probe and movable platform's water bag from annealing furnace side into A0 area close to the downstream position of coating host machine, suspended in the glass ribbon above in annealing furnace, the data collected and operation result are transmitted to man-machine interface, after comparing with target data, coating process parameters are corrected, and quality control is realized by timely control coating unit;The application has simple structure, plug and play, simple and fast, convenient maintenance;At the same time, the application greatly reduces resource waste and production loss, stabilizes production line temperature gradient, avoids a large amount of heat loss.

Description

Technical Field

[0001] This invention relates to a device and method for real-time quality inspection of the hot end of float glass online coating, and more particularly to a device and method for real-time measurement of the film structure and optical parameters of coated glass at high temperature at the front end of zone A of the annealing furnace in a float glass production line. Background Technology

[0002] Online coating is typically carried out in the tin bath or A0 zone of the annealing furnace in a float glass production line. Fluctuations in the atmosphere, temperature field, pressure field, and coating process parameters all affect product quality, making quality inspection particularly important. The most common offline quality inspection method in existing technology involves annealing, cooling, and cutting the coated glass strips, then testing their physical properties to check for compliance and uniformity. However, this process takes at least an hour from coating completion to sampling and testing. If coating quality fluctuates, this feedback method is clearly too slow. Adjusting process parameters only after receiving test results results in significant economic losses. Chinese patent publication number CN202502047U discloses a device for online measurement of the coating layer of float glass. The device is installed at the cold end of the float glass production line, in front of the cross-cutting station, and spans the float glass production line. It uses a moving probe to measure a standard glass plate and a glass strip to be tested in sequence, and measures parameters such as spectral reflectance and color parameters of the coated glass in real time online. At this time, the temperature of the glass plate is 60℃~70℃. Although the time from the completion of the coating process to real-time detection has been greatly shortened, it still generally takes 20 to 30 minutes. Feedback on quality fluctuations caused by variations in the coating process remains relatively delayed, posing a significant risk of production loss. Chinese Patent Publication No. CN 102520142A discloses an online hot-end detection device for coated glass annealing furnaces, including a hollow beam and a detection mechanism located within the cavity of the hollow beam. While this invention can promptly detect the surface quality of the coated glass and provide immediate feedback to on-site personnel, improving detection efficiency, the hollow beam, being horizontally spanning and fixed to the upper part of the A0 zone of the annealing furnace, causes significant damage to the overall structure of the furnace and results in substantial heat loss. It also makes installation, disassembly, and maintenance of the device inconvenient. Similarly, Chinese Patent Publication No. CN... Although Chinese patent 202501874U also discloses an online film layer measuring device in the high-temperature zone of a float glass production line, including a water-cooled cavity set in the upper part of the annealing furnace that spans the production line, and a measuring mechanism is installed in the water-cooled cavity, it also has problems such as causing significant damage to the furnace structure, easy heat dissipation, inconvenient installation, and difficulty in disassembly and maintenance.

[0003] Existing technologies still rely on manual monitoring to continuously observe data changes after real-time online coating quality inspection is completed, which poses a significant monitoring risk. Summary of the Invention

[0004] To address the aforementioned problems and overcome the shortcomings of existing technologies, this invention proposes a device and method for real-time quality detection of the hot end of float glass online coating.

[0005] The technical solution of this invention is as follows:

[0006] A real-time quality inspection device for the hot end of float glass online coating includes a suspension support mechanism, an optical inspection mechanism, a cooling protection mechanism, a calibration box, and a central control computer. The suspension support mechanism is equipped with a suspension rail and a traveling trolley. The optical inspection mechanism includes a spectrometer, a movable platform, and a sliding table assembly. The spectrometer is mounted on the movable platform, which is located on the slider of the sliding table assembly. The cooling protection mechanism includes a water tank with an elongated hole at the front end of its bottom plate for easy optical inspection. The spectrometer, movable platform, and sliding table assembly are housed within the water tank. The rear end of the water tank is fixedly connected to the front end of the calibration box, which is also fixedly connected to the front end of the traveling trolley. The traveling trolley can be suspended from the suspension rail by its wheels and can move horizontally. The movable platform is characterized by including a temperature compensation system and an audible and visual alarm system. The temperature compensation system is equipped with an electric heater, which is fixed at the top of the water bath. A hole is opened on one side of the annealing furnace. The front end of the water bath equipped with the electric heater can be inserted through the hole into a designated position near the downstream of the coating host in the A0 zone of the float glass production line annealing furnace at an ambient temperature of 550℃~600℃. It is suspended above the glass belt inside the annealing furnace. The spectrometer moves laterally with the movable platform and performs optical detection through the elongated hole in the bottom plate of the water bath. The detection data is transmitted to the human-machine interface of the central control computer. When the detection data is found to be abnormal when compared with the data in the calibration box, the audible and visual alarm system can issue a warning.

[0007] The detection device adopts a single-sided cantilever insertion structure, including a hanging support mechanism, an optical detection mechanism, a cooling protection mechanism, a calibration box, and a central control computer.

[0008] The optical testing mechanism includes a hot-end spectrometer (including data conversion and data cleaning modules), a movable platform, a sliding stage assembly, a cable chain, a walking motor, and power and communication cables. The spectrometer includes a spectral acquisition unit, optical fiber, collimating lens (including a probe), color temperature filter, and light source. The collimating lens is equipped with an angle adjuster, which allows adjustment of the collimating lens's angle to find a suitable position relative to the light source and the coated glass that has undergone the coating process in area A0, enabling real-time sampling of the glass's reflectance spectrum.

[0009] To reduce the monitoring risks for on-duty personnel, this invention includes an audible and visual alarm system. When abnormal detection data is detected, an alarm light flashes continuously or an alarm sound is emitted to prompt on-duty personnel to take action. The audible and visual alarm system is located in the central control room.

[0010] The cooling protection mechanism includes a water tank and a water circulation system. The water tank can be any geometric shape, such as a cuboid or cylinder, or an irregular shape, preferably a simple cuboid or cylinder. The water tank consists of an inner and outer layer forming a closed bag-like sandwich structure, with inlet and outlet ports. Optical detection devices and other necessary components, such as movable devices and cables, can be placed inside the water tank through the bag opening. Both the inner and outer layers of the water tank are made of heat-insulating and fire-resistant materials. The water tank can also be composed of a base plate, side plates, and a cover plate, forming a simple closed square structure. The base plate and side plates are welded together as a whole. Both the base plate and the side plates are closed sandwich structures, with inlet and outlet ports. The cover plate is placed on the water tank, forming a closed space with the side plates and the base plate. Circulating cooling water can be injected into the sandwich structure of the water tank to reduce the detection environment temperature. The front end of the water tank base plate has an elongated hole to facilitate the optical mechanism's detection of the glass, and an air seal nozzle is provided next to the hole.

[0011] The front end of the water tank can be inserted into the annealing furnace, and the rear end of the water tank is fixedly connected to the calibration box via a flange.

[0012] The suspension support mechanism includes a suspension rail, a traveling trolley, and wheels. The suspension rail is equipped with a pipe rack and a cable chain. The traveling trolley has an electrical cabinet and an industrial air conditioner on its upper part, and a fixed beam at its front end. The traveling trolley is suspended from the suspension rail by its wheels and can move laterally. When the front end of the water tank entering the kiln reaches the designated position, the lateral movement of the trolley can be restricted by the fixed beam, and the trolley is fixedly connected to the calibration box by fixing bolts.

[0013] The optical inspection mechanism includes a spectrometer, a movable platform, a sliding stage assembly, a cable chain, a walking motor, and power and communication cables. The sliding stage assembly has a slider. The spectrometer is mounted on the movable platform, which is located on the slider of the sliding stage assembly. The spectrometer, equipped with spectral measurement elements and probes, is fixed on the movable platform and placed inside a water tank of the cooling protection mechanism. The sliding stage assembly and cable chain are fixedly connected to the bottom plate of the inner layer of the water tank, and the movable platform is fixed to the slider of the sliding stage assembly. The power and communication cables are arranged inside the cable chain and can move with the movable platform. The movable platform is equipped with a positioning photoelectric switch to ensure accurate measurement position and a limit switch to ensure the mechanical safety of the measurement components. When the movable platform moves to the maintenance area, the protective cover can be opened to remove it entirely for maintenance.

[0014] In summary, the insertable cantilever structure of the present invention has a portion that can be inserted into the annealing furnace, which is the front end of the water bath, and contains a spectral measurement element, a probe, a movable platform, etc.

[0015] To avoid significant damage to the annealing kiln structure caused by the installation of the hot-end detection device, which would affect the uniform temperature field inside the kiln and the normal temperature gradient of the online coating production line, this invention adopts a method of opening an opening only on one side of the annealing kiln body. The water bag containing the optical detection device is inserted through the opening into the downstream position of the glass belt in the A0 zone of the float glass production line, close to the coating host and located on the upper part of the continuously running glass belt. It is then suspended above the glass belt inside the annealing kiln by the hanging support mechanism.

[0016] Specifically, a horizontal opening is made on one side of the annealing furnace. A water bath containing optical detection devices such as a spectral measuring element, probe, movable platform, and slider assembly is inserted through this opening into the downstream position of the A0 zone of the float glass production line, which operates at an ambient temperature of 550℃~600℃, near the coating host and above the continuously running glass belt. The water bath is suspended above the glass belt inside the annealing furnace by a support mechanism, allowing the movable platform to move laterally via a stepper motor. This method of inserting the detection device through the opening significantly reduces heat loss, and installation and disassembly are extremely simple and quick. The shape and size of the opening are matched to the shape and size of the device inserted into the annealing furnace.

[0017] In addition, to maintain a stable temperature field in the annealing furnace and a normal temperature gradient in the production line, and to compensate for heat loss from the openings and the water tank, the present invention also includes an electric heating temperature compensation mechanism in the detection device. The temperature compensation mechanism includes an electric heater and a heating monitoring system, with the electric heater horizontally fixed to the top of the water tank that can be inserted into the annealing furnace.

[0018] The electric heating temperature compensation mechanism is provided by the heating monitoring system to compensate for the heat loss caused by heat dissipation from the openings of the annealing furnace and heat absorption by the water bath. It automatically turns the electric heater on or off to maintain the stability of the internal temperature field of the annealing furnace and ensure the annealing quality of the coated glass.

[0019] In addition, to minimize heat loss, the present invention provides an end cap at the rear end of the water tank, near the kiln opening, which is integrally fixed to the water tank. The end cap has a central port through which the rear end of the water tank, the inlet and outlet pipes of the water circulation system, the cables of the optical detection device and the electric heater, etc., pass. The inlet and outlet pipes, optical detection device, and electric heater cables extend from the periphery of the water tank. The optimal length of the water tank is calculated based on the width of the glass plate to be tested inside the annealing kiln and the kiln thickness. Ideally, the rear end of the water tank and the end cap should tightly seal the opening after the front end of the water tank is inserted into the designated position inside the kiln. The end cap is made of heat-insulating refractory material, preferably ceramic or glass fiber heat-insulating material.

[0020] The optical inspection mechanism is mainly responsible for collecting real-time data of the reflection spectrum of the glass plate; the data cleaning and processing structure is mainly responsible for processing the real-time data of the reflection spectrum and interactive design; the cooling protection mechanism is responsible for high-temperature isolation and cooling protection of optical devices and data transmission systems; the hanging support mechanism is mainly responsible for the lateral movement of the traveling vehicle and water tank, and inserting the front end of the water tank into the designated position in the annealing furnace and fixing it.

[0021] Meanwhile, this invention also proposes a method for real-time quality inspection of coated glass that has completed the online coating process at the hot end (A0 zone) of a float glass production line using the aforementioned detection device, comprising the following steps:

[0022] (1) First, the spectrometer is installed on the movable platform. The movable platform is located on the slider of the slide assembly. The cooling protection mechanism is equipped with a water tank. A long hole is provided at the front end of the bottom plate of the water tank to facilitate optical detection. The spectrometer and the movable platform are located inside the water tank. The rear end of the water tank is fixedly connected to the front end of the calibration box. The rear end of the calibration box is fixedly connected to the front end of the traveling vehicle. The traveling vehicle is pushed to move laterally on the hanging rail.

[0023] (2) Make a hole on one side of the annealing kiln. The shape and size of the hole are determined according to the shape and size of the water tank front end that can be inserted into the kiln body.

[0024] (3) The front end of the water tank equipped with an electric heater is inserted through the above-mentioned opening into the downstream position of the A0 zone of the float glass production line annealing furnace, which is located near the coating host, at an ambient temperature of 550℃~600℃, and is suspended above the glass belt inside the annealing furnace.

[0025] (4) When the front end of the water bag is inserted into the designated position inside the kiln, the rear end of the water bag and the end cap can just seal the opening tightly.

[0026] (5) When the power is turned on, the detection device starts to work and the heating temperature compensation mechanism is turned on, and the electric heater heats up.

[0027] (6) After the online coating process of float glass is completed, the spectral measurement element and probe located at the front end of the water bath are driven by the walking motor to move laterally with the movable platform, and the optical parameters of the coated glass are directly measured under the condition that the glass strip temperature is 550℃~600℃.

[0028] (7) The collected data is transmitted to the central computer human-machine interface to calculate the film thickness and refractive index. The detection data obtained under the condition of ambient temperature of 550℃~600℃ is compared and corrected with the data obtained under the condition of normal temperature. The correction coefficient is 1.02, that is, the refractive index value calculated under the high temperature condition of 550℃~600℃ is 1.02 times that under the condition of normal temperature. The measured value and calculation result are compared with the target data in combination with the correction coefficient, and the coating process parameters are corrected in time to keep the film structure and optical indicators stable within the product quality target range.

[0029] In other words, the method described in this invention can measure the optical parameters (visible light reflectance, chromaticity coordinates, etc.) of the coated glass under hot conditions (glass strip temperature 550℃~600℃) immediately after the coating process is completed, calculate the film thickness and refractive index, compare them with the target values, and feed them back to the process operating system. Based on the deviation between the measured values ​​and the target values, the process parameters are adjusted in a timely manner to keep the film structure stable within the target range. This avoids product defects caused by process deviations and reduces the risk of production losses.

[0030] Specifically, to achieve the above objectives, this invention places a hot-end quality detection device immediately downstream of the coating reactor in the A0 zone of the annealing furnace. This device is arranged on one side of the float glass production line, interspersed with the glass belt drive of the coating main unit in the A0 zone, at an ambient temperature of 550℃~600℃. In the hot-end detection device, the spectral acquisition unit and probe of the optical detection mechanism are mounted on a movable platform. This movable platform is installed inside a cooling water tank and can move laterally via a stepper motor. The front end of the water tank can enter and exit the A0 zone of the annealing furnace. The movable platform receives the reflection spectrum in real time at a designated position, calculates the results, and then transmits them to the central control computer's human-machine interface to achieve the testing and control of the thermal conditions.

[0031] Typically, in the production of online Low-E glass, the conductive functional layer is applied to the surface of the glass strip in zone A0 of the float glass annealing furnace at a temperature of 600°C. Within two minutes of the functional layer being deposited, the visible light reflectance, chromaticity indices L*, a*, and b* of the film can be rapidly measured, and the film thickness and refractive index can be calculated. These values ​​are then compared with the target values ​​and fed back to the process parameter control system for adjustment. Based on the deviation between the measured and target values, the process parameters are adjusted in a timely manner, enabling online real-time measurement and control to keep the film structure stably within the target range.

[0032] During the coating process, the coated glass belt is continuously transported. When it reaches the hot-end spectrometer, the spectrometer measures the optical parameters of the coated glass (including visible light reflectance, chromaticity coordinates L*, a*, and b*). The measurement results are transmitted to the optical analysis processor, input into the optical structure model, and the film thickness and refractive index are calculated. The data is then compared with an empirical database, corrected, and the deviation between the measured structural parameters and the target values ​​is determined. The measured parameters and deviation values ​​are then input into the process operating system. Based on the analysis results from the empirical process parameter database, the process parameters are automatically adjusted. If the film thickness is too large, the concentration of the main coating raw material is reduced; if the film thickness is too small, the concentration of the main coating raw material is increased. Other auxiliary gases (including catalysts, reinforcing agents, diluents, etc.) are adjusted according to the proportion of the main raw materials. This achieves automatic measurement and control of the film structure.

[0033] The device of the present invention has a simple structure, and insertion and withdrawal are simple and quick, making it convenient for installation and maintenance. At the same time, the method of the present invention greatly reduces resource waste and production losses, while stabilizing the temperature gradient of the production line and avoiding a large amount of heat loss. Attached Figure Description

[0034] Figure 1 This is a structural diagram of the spectrometer in this invention;

[0035] Figure 2 This is a top cross-sectional view of the detection device in this invention;

[0036] Figure 3 This is a front view of the detection device in this invention;

[0037] Figure 4 This is a flowchart of the detection process in this invention. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] Example 1

[0040] This invention proposes a device and method for real-time quality detection of the hot end of float glass online coating. The device includes a hanging support mechanism, an optical detection mechanism, a cooling protection mechanism, a calibration box 305, and a central control computer. The hanging support mechanism is equipped with a hanging rail 311 and a traveling vehicle 308. The optical detection mechanism is equipped with a spectrometer, a movable platform 203, and a sliding table assembly 201. The spectrometer is mounted on the movable platform 203, which is located on the slider of the sliding table assembly 201. The cooling protection mechanism is equipped with a water tank 202. An elongated hole for optical detection is provided at the front end of the bottom plate of the water tank 202. The spectrometer and the movable platform 203 are located inside the water tank 202. The rear end of the water tank 202 is fixedly connected to the front end of the calibration box 305. The rear end of the calibration box 305 is fixedly connected to the front end of the traveling vehicle 308. The traveling vehicle 308 can be suspended on the hanging rail 311 by wheels 313 and can move laterally.

[0041] Furthermore, the device of the present invention also includes an audible and visual alarm system and a temperature compensation system. An opening is provided on one side of the annealing furnace. One end of the water tank containing the optical detection devices such as the spectrometer and the movable platform can be inserted through the opening into a designated downstream position near the coating host in the annealing furnace 301A0 area of ​​the float glass production line with an ambient temperature of 550℃~600℃. It is suspended above the glass belt inside the annealing furnace. The walking motor and the drag chain 204 can drive the movable platform 203 to move laterally. The spectral acquisition unit and the probe can perform optical detection through the elongated hole in the bottom plate of the water tank 202 and transmit the detection data to the human-machine interface of the central control computer.

[0042] Specifically, this invention proposes an online float glass coating hot-end quality inspection device. The device employs a single-sided cantilever insertion structure, which, compared to the commonly used method of spanning both sides of the annealing kiln 301, aims to minimize structural damage and heat loss caused by arranging the inspection device. The structure of this invention is plug-and-play, extremely convenient to install, disassemble, and maintain, and can perform continuous or short-term periodic inspections.

[0043] To reduce the monitoring risks for on-duty personnel and prevent negligence, this invention also includes an audible and visual alarm system. When abnormal detection data is detected, an alarm light flashes continuously or an alarm sound is emitted to prompt on-duty personnel to take action. The audible and visual alarm system is located in the human-machine interface host in the central control room.

[0044] In addition, in order to maintain the stability of the temperature field of the annealing furnace 301 and the normal temperature gradient of the production line, and to compensate for the heat loss from the opening and the heat absorption of the water tank 202, the present invention also provides an electric heating temperature compensation mechanism in the detection device.

[0045] To facilitate the insertion of the detection device, an opening is made on one side of the annealing furnace 301. The water tank 202, which contains the spectrometer, movable platform 203, etc., is inserted through the opening into a designated downstream position in the A0 zone of the float glass production line, which has an ambient temperature of 550℃~600℃, near the coating host and above the continuously running glass belt. It is suspended above the glass belt inside the annealing furnace 301 by the support mechanism.

[0046] The shape and size of the opening in the annealing furnace 301 match the shape and size of the insertion device, greatly reducing heat loss and making installation and disassembly very simple and quick. The opening can be square, round, or other geometric shapes, or any irregular shape, but square or round is preferred.

[0047] The optical inspection mechanism includes a spectrometer, a movable platform 203, a sliding stage assembly 201, a cable chain 204, a walking motor, and optical inspection devices such as power cords and communication cables. The sliding stage assembly 201 has a slider. The spectrometer is mounted on the movable platform 203, which is located on the slider of the sliding stage assembly 201. The spectrometer, equipped with spectral measurement elements and a probe, is fixed on the movable platform 203 and placed inside the water tank 202 of the cooling protection mechanism. The sliding stage assembly 201, cable chain 204, etc., are fixedly connected to the bottom plate of the inner layer of the water tank 202, and the movable platform 203 is fixed to the slider of the sliding stage assembly 201. The power cord and communication cable are arranged inside the cable chain 204 and can move with the movable platform 203. The movable platform 203 is equipped with a positioning photoelectric switch 208 and a shielding plate 207 to ensure accurate measurement position and mechanical safety of the measurement components. When moved to the maintenance area, the entire assembly can be removed for maintenance by opening the protective cover.

[0048] The spectrometer (including data conversion and data cleaning modules) includes a spectral acquisition unit, an optical fiber 105, a collimating lens 103, a color temperature filter 102, and a light source 101. The collimating lens 103 is equipped with an angle adjuster. The angle of the collimating lens 103 can be adjusted by the angle adjuster 104 to find a suitable position relative to the light source 101 and the coated glass 106 that has completed the coating process in area A0, and to sample the reflection spectrum of the glass in real time.

[0049] The cooling protection mechanism includes a water tank 202 and a water circulation system. The water tank 202 is a cuboid, composed of a base plate, side plates, and a cover plate, with the base plate and side plates welded together as a single unit. Both the base plate and the side plates are closed sandwich structures, equipped with inlets and outlets. The cover plate is placed on the water tank 202, forming a closed space with the side plates and the base plate. Circulating cooling water can be injected into the sandwich structure of the water tank 202 to reduce the ambient temperature of the detection environment. The front end of the base plate of the water tank 202 has an elongated hole to facilitate the optical mechanism's detection of the glass, and an air seal is located next to the hole.

[0050] The front end of the water bath can be inserted into the annealing furnace, while a very small portion of the rear end of the water bath remains outside the annealing furnace. The rear end of the water bath is fixedly connected to the calibration box via a flange, or it can be fixedly connected to the calibration box via bolts.

[0051] In this invention, an end cap 304 is provided at the rear end of the water jacket 202, near the kiln opening, and is fixed integrally with the water jacket 202. The end cap 304 has a central port, through which the rear end of the water jacket 202, the inlet and outlet pipes of the water circulation system, the cables of the optical detection device and the electric heater 303, etc., pass. The inlet and outlet pipes, the cables of the optical detection device and the electric heater 303, etc., are led out from the periphery of the water jacket 202. The optimal length of the water jacket 202 is calculated based on the width of the glass plate to be tested inside the annealing kiln 301 and the kiln thickness. Ideally, after the front end 303 of the water jacket 202 is inserted into the designated position inside the kiln, the rear end of the water jacket 202 and the end cap 304 should precisely seal the opening. The end cap 304 is made of heat-insulating refractory material, preferably ceramic or glass fiber heat-insulating material.

[0052] The suspension support mechanism includes a suspension rail 311, a traveling trolley 308, wheels 313, etc. The suspension rail 311 is equipped with a pipe rack 314 and a pipe drag chain 312. The traveling trolley 308 is equipped with an electrical cabinet 309 and an industrial air conditioner 310 on its upper part and a fixed beam 306 at its front end. The traveling trolley 308 is suspended on the suspension rail 311 by the wheels 313 and can move laterally. When the front end 303 of the water tank 202 inside the kiln reaches the designated position, the lateral movement of the trolley can be restricted by the fixed beam 306, and the trolley can be fixedly connected to the calibration box by fixing bolts.

[0053] In addition, in order to maintain the stability of the temperature field of the annealing furnace 301 and the normal temperature gradient of the production line, and to compensate for the heat loss from the opening and the heat absorption of the water tank 202, the present invention also provides an electric heating temperature compensation mechanism in the detection device.

[0054] The temperature compensation mechanism includes an electric heater 303 and a heating monitoring system. The electric heater 303 is horizontally fixed to the top of a water tank 202 that can be inserted into an annealing furnace 301.

[0055] The electric heating temperature compensation mechanism, controlled by the heating monitoring system, compensates for heat loss caused by heat dissipation from the openings in the annealing furnace 301 and heat absorption by the water bath 202. It automatically turns the electric heater 303 on or off to maintain a stable internal temperature field in the annealing furnace 301 and ensure the annealing quality of the coated glass.

[0056] The optical detection mechanism is mainly responsible for collecting real-time data of the reflection spectrum of the glass plate; the data cleaning and processing structure is mainly responsible for processing the real-time reflection spectrum data and interactive design; the cooling protection mechanism is responsible for high-temperature isolation and cooling protection of optical devices and data transmission systems; the hanging support mechanism is mainly responsible for the lateral movement of the traveling vehicle 308 and the water tank 202, as well as inserting the front end 303 of the water tank 202 into the designated position in the annealing furnace 301 and fixing it.

[0057] In addition, the present invention also proposes a method for hot-end quality inspection of float glass online coating using the above-mentioned quality inspection device, comprising the following steps:

[0058] (1) First, install the spectrometer on the movable platform 203. The movable platform 203 is located on the slider of the slide assembly 201. The cooling protection mechanism is provided with a water tank 202. A long hole is provided at the front end of the bottom plate of the water tank 202 to facilitate optical detection. The spectrometer and the movable platform 203 are located inside the water tank 202. The rear end of the water tank 202 is fixedly connected to the front end of the calibration box 305. The rear end of the calibration box 305 is fixedly connected to the front end of the traveling vehicle 308. Push the traveling vehicle 308 to move laterally on the hanging rail 311.

[0059] (2) An opening is made on one side of the annealing kiln 301. The shape and size of the opening are determined according to the shape and size of the water tank 202 that can be inserted into the kiln body.

[0060] (3) The front end 303 of the water bag 202 is inserted through the above-mentioned opening into the downstream position of the annealing furnace 301A0 area of ​​the float glass production line with an ambient temperature of 550℃~600℃, and is suspended above the glass 302 belt inside the annealing furnace 301.

[0061] (4) When the front end 303 of the water tank 202 is inserted into the designated position inside the kiln, the rear end of the water tank 202 and the end cap 304 can just seal the opening tightly.

[0062] (5) When the power is turned on, the detection device starts to work and the heating temperature compensation mechanism is turned on, and the electric heater 303 heats up.

[0063] (6) After the float glass completes the online coating process, the spectral measurement element and probe located at the front end of the water bath 202 are driven by the walking motor to move laterally with the movable platform 203, and the optical parameters of the coated glass are directly measured under the condition that the glass strip temperature is 550℃~600℃.

[0064] (7) The collected data is transmitted to the central computer human-machine interface to calculate the film thickness and refractive index. The detection data obtained under the condition of ambient temperature of 550℃~600℃ is compared and corrected with the data obtained under the condition of normal temperature. The correction coefficient is 1.02, that is, the refractive index value calculated under the high temperature condition of 550℃~600℃ is 1.02 times that under the condition of normal temperature. The measured value and calculation result are compared with the target data in combination with the correction coefficient, and the coating process parameters are corrected in time to keep the film structure and optical indicators stable within the product quality target range.

[0065] Specifically, the method described in this invention can measure the optical parameters (visible light reflectance, chromaticity coordinates, etc.) of the coated glass under hot conditions (glass strip temperature 550℃~600℃) immediately after the coating process is completed, calculate the film thickness and refractive index, compare them with target values, and feed them back to the process operating system. Based on the deviation between the measured values ​​and the target values, the process parameters are adjusted in a timely manner to keep the film structure stable within the target range. This avoids product defects caused by process deviations and reduces the risk of production losses.

[0066] This invention places a hot-end optical detection device immediately downstream of the coating reactor in the annealing furnace 301A0 zone. This device is arranged on one side, interspersed and positioned immediately downstream of the main coating glass belt in the A0 zone of the float glass production line, at an ambient temperature of 550℃~600℃. The spectral acquisition unit of the optical mechanism in the hot-end detection device is mounted on a movable platform 203. The movable platform 203 is installed inside a cooling water tank 202 and can move laterally via a stepper motor, allowing it to enter and exit the annealing furnace 301A0 zone. When the movable platform 203 reaches a designated position, it receives the reflection spectrum in real time, calculates the results, and then transmits them to the human-machine interface, enabling the testing and control of thermal conditions.

[0067] Typically, during the production of online Low-E glass, the conductive functional layer is applied to the surface of the glass strip in zone 301A0 of the float glass annealing furnace at a temperature of 600℃. Within two minutes of the functional layer being deposited, the visible light reflectance, chromaticity indices L*, a*, and b* of the film can be rapidly measured, and the film thickness and refractive index can be calculated. These values ​​are then compared with the target values ​​and fed back to the process parameter control system for adjustment. Based on the deviation between the measured and target values, the process parameters are adjusted in a timely manner, enabling online real-time measurement and control to keep the film structure stably within the target range.

[0068] During the coating process, the coated glass belt is continuously transported. When it reaches the hot-end spectrometer, the spectrometer measures the optical parameters of the coated glass (including visible light reflectance, chromaticity coordinates L*, a*, and b*). The measurement results are transmitted to the optical analysis processor, input into the optical structure model, and the film thickness and refractive index are calculated. The data is then compared with an empirical database, corrected, and the deviation between the measured structural parameters and the target values ​​is determined. The measured parameters and deviation values ​​are then input into the process operating system. Based on the analysis results from the empirical process parameter database, the process parameters are automatically adjusted. If the film thickness is too large, the concentration of the main coating raw material is reduced; if the film thickness is too small, the concentration of the main coating raw material is increased. Other auxiliary gases (including catalysts, reinforcing agents, diluents, etc.) are adjusted according to the proportion of the main raw materials. This achieves automatic measurement and control of the film structure.

[0069] The aforementioned calculation method is based on a thin-film interference theory model:

[0070] n=√((1.52(1+√R)) / (1-√R))

[0071] d=(λ_1λ_2) / (2n(λ_1-λ_2))

[0072] In the formula, n is the refractive index of the film being measured, R is the extreme value of the reflectivity of the film being measured, d is the thickness of the film being measured, and λ1 and λ2 are adjacent extreme wavelengths (λ1>λ2).

[0073] The test was conducted under hot conditions of 550℃ to 600℃. Since the glass density, intrinsic frequency of electron vibration, and thermal radiation coefficient are different from those at room temperature, there is an error compared with the room temperature model. A correction coefficient K value needs to be assigned based on the empirical database. The correction coefficient was calculated and determined to be 1.015 to 1.025, with an average value of 1.02. That is, the refractive index value calculated under high temperature conditions is 1.02 times that under room temperature conditions.

[0074] Using the apparatus and method proposed in this invention, the coated glass is immediately measured and calculated after the coating process is completed, and process feedback is generated. This allows for timely adjustment of process parameters, ensuring that the coated product meets the set functional and quality requirements. In online Low-E coating production, the functional layer is completed within the annealing furnace 301A0 zone, and this feedback time can be completed within 2 minutes. This effectively solves the problem of delayed glass quality inspection and feedback time, significantly reducing quality fluctuation losses caused by coating process variations.

[0075] During the coating process, the coated glass belt is continuously transported. When it reaches the hot-end spectrometer, the spectrometer measures the optical parameters of the coated glass (including visible light reflectance, chromaticity coordinates L*, a*, and b*). The measurement results are transmitted to the optical analysis processor, input into the optical structure model, and the film thickness and refractive index are calculated. The data is then compared with an empirical database, corrected, and the deviation between the measured structural parameters and the target values ​​is determined. The measured parameters and deviation values ​​are then input into the process operating system. Based on the analysis results from the empirical process parameter database, the process parameters are automatically adjusted. If the film thickness is too large, the concentration of the main coating raw material is reduced; if the film thickness is too small, the concentration of the main coating raw material is increased. Other auxiliary gases (including catalysts, reinforcing agents, diluents, etc.) are adjusted according to the proportion of the main raw materials. This achieves automatic measurement and control of the film structure, realizing intelligent production control.

[0076] The process control procedure is as follows: The raw spectral processing module collects reflectance data of the 380–830 nm spectrum through a mechanism on the movable platform 203. It then uses the CIE color model library to calculate the L*a*b value at any given time in real time and uses light interference to calculate the thickness of the film layer being measured in real time. The data cleaning module includes processor hardware, software cleaning algorithms, and a real-time database. The processor, including but not limited to PLCs and industrial computers, is the hardware carrier for data cleaning. The software cleaning algorithm identifies and handles various data quality issues: calibrating bright and dark spectra, correcting and cleaning the raw spectrum, compensating for optical shifts caused by roller fluctuations in the float glass production line, compensating for measurement shifts caused by temperature fluctuations, and performing RGB conversion and color rendering, ensuring the reliability and stability of the measured data. Finally, the processed data is transmitted to the real-time database, which stores historical records of all values ​​for later query and comparison. It also includes a human-machine interface, such as a spectral waveform demonstration diagram, real-time and historical curves of L*a*b*, etc., monitoring all relevant data and ensuring the stability and reliability of the measured data by adjusting parameters such as integration time and smoothing coefficient. By calling the coating experience database and comparing the results of film thickness calculation and L*a*b* numerical calculation, the current production quality is monitored in real time and the process is corrected. For example, when L*a*b* deviates, the fluctuation trend of the required raw materials is deduced in reverse based on the characteristics of the produced products. Combined with factors such as temperature changes in A0 area, SO2 concentration changes, and glass plate vibration changes, the required compensation direction and quantity are determined. By adjusting variables such as process gas concentration or process liquid flow rate through the control system, the stable production is ensured.

[0077] Taking the production of fluorine-doped tin dioxide transparent conductive glass (SnO2:F, abbreviated as FTO) as an example, monobutyltin trichloride (MBTC) is used as the tin source and the main raw material for coating. Oxygen (O2) is used as the oxidant, hydrofluoric acid (HF) as the dopant, water (H2O) as the catalyst, ammonia (NH3) as the reinforcing agent, and nitrogen (N2) as the diluent. During the coating process, optical parameters (including visible light reflectance, chromaticity coordinates L*, a*, and b* values) are measured in real time, and the film thickness is calculated using an optical model. If the calculated thickness is greater than the target film thickness, the MBTC concentration is reduced; if the calculated thickness is less than the target film thickness, the MBTC concentration is increased. The magnitude of the increase or decrease in concentration is based on the analysis results of an empirical process parameter database. The concentrations of other gases are adjusted synchronously according to the formula ratio.

[0078] The present invention has a simple structure, and insertion and removal are easy and quick, making it convenient for installation and maintenance. At the same time, the method of the present invention greatly reduces resource waste and production losses, while stabilizing the temperature gradient of the production line and avoiding a large amount of heat loss.

[0079] Example 2

[0080] Similar to Example 1, the present invention is preferably carried out at an ambient temperature of 550°C.

[0081] Real-time quality testing is preferably performed at an ambient temperature of 550℃. The aim is to measure the film thickness and refractive index data obtained by calculation based on the thin film interference theory model under this testing temperature environment, and then compare and correct the test data obtained under the hot state condition of 550℃ with the data obtained under the normal temperature condition.

[0082] Based on the correction factor K assigned by the testing experience database, the correction factor in this embodiment is calculated to be 1.015, which means that the refractive index value calculated under a high temperature of 550℃ is 1.015 times that under normal temperature conditions.

[0083] Example 3

[0084] Similar to Example 1, this invention is carried out at an ambient temperature of 600°C.

[0085] Real-time quality testing is preferably performed at an ambient temperature of 600℃. The aim is to measure the film thickness and refractive index data obtained by calculation based on the thin film interference theory model under this testing temperature environment, and then compare and correct the test data obtained under the hot state condition of 600℃ with the data obtained under the normal temperature condition.

[0086] Based on the correction factor K assigned by the testing experience database, the correction factor in this embodiment is calculated to be 1.025, which means that the refractive index value calculated under a high temperature of 600℃ is 1.025 times that under normal temperature conditions.

[0087] It should be noted that the above embodiments only illustrate some implementation methods of the present invention and are not intended to limit the present invention in any way. Any modifications and improvements made in accordance with the concept of the present invention will fall within the protection scope of the present invention.

Claims

1. A method for real-time quality inspection of the hot end of float glass online coating, utilizing a real-time quality inspection device for the hot end of float glass online coating. The device includes a suspension support mechanism, an optical inspection mechanism, a cooling protection mechanism, a calibration box, and a central control computer. The suspension support mechanism is equipped with a suspension rail and a traveling trolley. The optical inspection mechanism includes a spectrometer, a movable platform, and a sliding table assembly. The spectrometer is mounted on the movable platform, which is located on the slider of the sliding table assembly. The cooling protection mechanism includes a water tank with an elongated hole at the front end of the water tank's bottom plate for easy optical inspection. The spectrometer, movable platform, and sliding table assembly are housed within the water tank. The rear end of the water tank is fixedly connected to the front end of the calibration box, and the rear end of the calibration box is fixedly connected to the front end of the traveling trolley. The traveling trolley is suspended from the suspension rail by wheels and moves laterally. The method is characterized by: The detection device also includes a temperature compensation system and an audible and visual alarm system. The temperature compensation system is equipped with an electric heater, which is fixed at the top of the water bath. An opening is made on one side of the annealing furnace. The front end of the water bath, equipped with the electric heater, is inserted through the opening into a designated position near the downstream of the coating host in the A0 zone of the float glass production line annealing furnace, where the ambient temperature is 550℃~600℃. It is suspended above the glass belt inside the annealing furnace. The spectrometer moves laterally with the movable platform and performs optical detection through an elongated hole in the bottom plate of the water bath. The detection data is transmitted to the human-machine interface of the central control computer. When an anomaly is found when comparing the detection data with the data from the calibration box, the audible and visual alarm system issues a warning, including the following steps: (1) First, the spectrometer is installed on the movable platform. The movable platform is located on the slider of the slide assembly. The cooling protection mechanism is equipped with a water tank. A long hole is provided at the front end of the bottom plate of the water tank to facilitate optical detection. The spectrometer and the movable platform are located inside the water tank. The rear end of the water tank is fixedly connected to the front end of the calibration box. The rear end of the calibration box is fixedly connected to the front end of the traveling vehicle. The traveling vehicle is pushed to move laterally on the hanging rail. (2) Make an opening on one side of the annealing furnace. The shape and size of the opening are determined according to the shape and size of the water tank front end that can be inserted into the furnace body; (3) Insert the front end of the water tank equipped with an electric heater into the downstream position of the A0 zone of the float glass production line annealing furnace with an ambient temperature of 550℃~600℃ through the above opening, and suspend it above the glass belt inside the annealing furnace. (4) When the front end of the water bag is inserted into the designated position inside the kiln, the rear end of the water bag and the end cap can just seal the opening tightly. (5) When the power is turned on, the detection device starts to work and the heating temperature compensation mechanism is turned on, and the electric heater heats up. (6) After the online coating process of float glass is completed, the spectral measurement element and probe located at the front end of the water bath are driven by the walking motor to move laterally with the movable platform, and the optical parameters of the coated glass are directly measured under the condition that the glass strip temperature is 550℃~600℃. (7) The collected data is transmitted to the central computer human-machine interface to calculate the film thickness and refractive index. The detection data obtained under the condition of ambient temperature of 550℃~600℃ is compared and corrected with the data obtained under the condition of normal temperature. The correction coefficient is 1.02, that is, the refractive index value calculated under the high temperature condition of 550℃~600℃ is 1.02 times that under the condition of normal temperature. The measured value and calculation result are compared with the target data in combination with the correction coefficient, and the coating process parameters are corrected in time to keep the film structure and optical indicators stable within the product quality target range.

2. The method for real-time quality detection of the hot end of float glass online coating according to claim 1, characterized in that: The water tank has an end cap at its rear end, which is near the opening in the kiln body. The end cap is fixed to the water tank as a whole. When the front end of the water tank is inserted into the designated position inside the kiln body, the rear end of the water tank and the end cap can tightly seal the opening.

3. The method for real-time quality detection of the hot end of float glass online coating according to claim 1, characterized in that: The water tank has a cuboid structure, consisting of a bottom plate, side plates, and a cover plate. The bottom plate and side plates are welded together as a whole. The cover plate is placed on the water tank and forms a closed space with the side plates and bottom plate. The water tank is provided with a water inlet and a water outlet, and an air seal is provided next to the elongated hole at the front end of the bottom plate.

4. The method for real-time quality detection of the hot end of float glass online coating according to claim 1, characterized in that: The traveling vehicle is also equipped with an electrical control cabinet, an industrial air conditioner, and a fixed beam, which limits the lateral movement of the vehicle.

5. The method for real-time quality detection of the hot end of float glass online coating according to claim 1, characterized in that: The opening on one side of the annealing furnace is square or round, and the shape and size of the opening match the insertion device.

6. The method for real-time quality detection of the hot end of float glass online coating according to claim 1, characterized in that: The temperature compensation system also includes a suspension system and a heating monitoring system.

7. The method for real-time quality detection of the hot end of float glass online coating according to claim 2, characterized in that: The end cap is made of heat-insulating material.

8. The method for real-time quality detection of the hot end of float glass online coating according to claim 1, characterized in that: The optical parameters of the coated glass detected by the optical inspection agency, including visible light reflectance and chromaticity coordinates L*, a*, and b*, are transmitted to the optical analysis processor and input into the optical structure model. The calculated film thickness and refractive index data are then compared with the empirical database and corrected with the reference correction system data. This allows us to know the deviation between the detected values ​​and the target value range using the method.

9. A method for real-time quality detection of the hot end of float glass online coating according to claim 8, characterized in that: If the film thickness and optical performance values ​​of the coated glass detected in real time using the method described above exceed the target value range when compared with the data from the calibration box, it indicates that the online coating quality is abnormal, and the audible and visual alarm system will issue an alarm signal.

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