High-generation display glass production process

Abstract

Disclosed in the present invention is a high-generation display glass production process. In the production process, by differentially controlling the heating temperatures of various sections in a sectional heating melting furnace, a controllable distribution of a thermal field within the melting furnace is achieved; and by combining the sectional heating melting furnace and a staged bubble-removing and clarifying apparatus, a synergistic effect is achieved between the two process steps, ensuring a low microbubble residual rate and low energy consumption, and improving the flow velocity and flow rate of glass melt, thereby increasing production output. By using a tin bath apparatus in which tin vapor and tin bath waste gas in different areas are differentially exhausted, precise control over air inlet and exhaust of the tin bath and precise control over a temperature field are achieved. According to the present invention, combined and innovative research is performed on a plurality of working procedures of a display glass substrate production process, so as to form a display glass substrate production process in which resources are fully utilized, synergistic complementarity of advantages is achieved, and organic unity of a production line is maintained.

Description

A high-generation display glass production process Technical Field

[0001] The present invention relates to the field of glass production technology, and in particular to a manufacturing device and a production process suitable for preparing display glass with low devitrification and low defect rate, as well as an optical element manufacturing method for manufacturing optical elements from a glass formed body obtained by using the device and process, and the optical elements manufactured. Background Art

[0002] Display glass substrates are key strategic materials for the information display industry, representing the highest level of glass manufacturing. Producing high-quality, high-end, and advanced-generation display glass substrates using intelligent, green, low-carbon, and scalable manufacturing processes is the goal of scientific research and development in this field.

[0003] Display devices, including LCDs, place extremely high demands on the surface and internal quality of glass substrates. Microbubbles are a crucial control parameter during the glass substrate manufacturing process. During the glass melting process, a large number of bubbles are generated. To obtain premium, high-end, and high-quality bubble-free molten glass, these bubbles must be eliminated to achieve an acceptable range and state for bubble defects in the glass substrate.

[0004] Today, glass substrates are developing significantly towards larger sizes and higher generations. Many manufacturers have increased the pulling capacity to increase production capacity. However, when the glass production capacity increases, the flow rate of the glass liquid in the channel will increase, and the residence time of bubbles in the clarification pipe section will be shortened, which greatly reduces the probability of bubbles gathering, growing, and floating. As a result, the clarification and bubble removal are not timely and thorough, forming residual microbubbles in the glass plate.

[0005] High-end display glass substrates mostly use alkali-free glass, which has a high melting temperature and high viscosity. Currently, the temperature of the glass liquid is increased to promote the aggregation, enlargement, floating and discharge of bubbles in the glass liquid.

[0006] However, the increased production capacity and temperature of glass melts result in significant energy consumption, which accounts for a relatively high proportion of energy consumption in the glass production process. Simply increasing the temperature of the glass melt to alter the process of bubble generation, aggregation, enlargement, buoyancy, and expulsion results in a relatively crude production method and a relatively simple control approach. To achieve the dual carbon goals and safeguard the security of my country's information display, the development of a high-end display glass substrate production process that meets the production requirements of scale and high production capacity, the quality requirements of low bubble defect rates, high surface flatness, and high generations, and the environmental and economic requirements of green, low energy consumption has always been a highly sought-after research and development direction in this field.

[0007] Summary of the Invention

[0008] In response to the above-mentioned problems, the purpose of the present invention is to propose an intelligent, green, low-carbon, large-scale high-generation display glass substrate manufacturing device and production process suitable for preparing display glass with low devitrification and low defect rate, as well as an optical element manufacturing method for manufacturing optical elements from the glass formed body obtained by using the device and process, and the optical element manufactured. The technical solution of the present invention can effectively reduce or eliminate residual microbubbles in the glass substrate, significantly improve the transmittance and uniformity of the glass substrate, and is suitable for preparing high-generation, high-quality display glass substrates, ensuring the safety of information display, and effectively reducing the energy consumption of the production line, achieving precise temperature control, helping the glass industry to save energy, reduce emissions and reduce consumption, and providing a technical option for achieving my country's dual carbon goals.

[0009] The present invention provides a device for producing display glass substrates, comprising a raw material mixing device, a segmented heating melting furnace, a graded bubble removal and clarification device, a tin bath, an annealing furnace, and a cutting and post-processing device.

[0010] Among them, the partially heated melting furnace includes a control part and a first melting part and a second melting part along the flow direction of the glass liquid. A furnace sill is arranged between the first melting part and the second melting part. A heating component is provided on the first melting part, and another heating component is provided on the second melting part. The control part can control the heating conditions of the first melting part and the second melting part respectively.

[0011] The graded bubble removal and clarification device includes a graded bubble removal and clarification channel, which includes several bubble removal structures for graded removal of bubbles in different depth areas of the glass liquid; the bubble removal structure includes a connecting pipe section and a clarification pipe section, and the inner diameter of the connecting pipe section is smaller than that of the clarification pipe section.

[0012] The control unit of the partially heated melting furnace controls and adjusts the temperature of the first melting unit and the temperature of the second melting unit respectively to adapt to the degassing process of the graded degassing and clarification channel.

[0013] The present invention also provides a production process for display glass substrates, which utilizes the above-mentioned production device for display glass substrates, including a raw material mixing step, a partial heating step, a graded bubble removal and clarification step, a tin bath forming step, an annealing step, a cutting and post-processing step.

[0014] Among them, the partial heating melting furnace in the partial heating step includes a control part and a first melting part and a second melting part along the flow direction of the glass liquid. A furnace sill is arranged between the first melting part and the second melting part. A heating component is provided on the first melting part, and another heating component is provided on the second melting part. The control part can control the heating of the first melting part and the second melting part respectively.

[0015] The graded bubble removal and clarification device in the graded bubble removal and clarification step includes a graded bubble removal and clarification channel, which includes several bubble removal structures for graded removal of bubbles in different depth areas of the glass liquid; the bubble removal structure includes a connecting pipe section and a clarification pipe section, and the inner diameter of the connecting pipe section is smaller than that of the clarification pipe section.

[0016] The control unit of the partially heated melting furnace controls and adjusts the temperature of the first melting unit and the temperature of the second melting unit respectively to adapt to the degassing process of the graded degassing and clarification channel.

[0017] Preferably, the present invention discloses the types and proportions of glass raw materials for producing display glass substrates. The use of such raw materials can improve the quality of the glass substrates, ensure the smooth operation of the production process, and make the production process green and environmentally friendly.

[0018] Preferably, the tin bath forming step adopts an advanced display glass protective gas implementation device, including a tin bath pool and a tin bath top cover, with several groups of space partitions fixedly installed on the inner side of the tin bath top cover, which separate the interior of the tin bath top cover into several top cover inner grooves through the space partitions, and the upper ends of the top cover inner grooves are fixedly installed with gas supply pipes, and an exhaust slit is opened on the breast wall above the tin bath pool, with several groups of exhaust pipes fixedly installed inside, and exhaust partitions that separate the exhaust slit into multiple independent grooves, and each of the above-mentioned independent grooves is provided with at least one exhaust pipe. In this way, the differentiated supply of protective gas in different areas and the differentiated discharge of tin vapor and waste gas in different areas in the tin bath can be realized autonomously and controllably, ensuring the supply of protective gas and the discharge of tin vapor and waste gas on demand, realizing precise control of air intake and exhaust, maintaining the consistency of the protective gas environment to the maximum extent, reducing the residence time of tin vapor in any place in the bath, reducing the probability of forming defects on the glass plate surface, and improving product quality.

[0019] Preferably, the front of the annealing lehr is provided with a transition roller table integrally connected to the annealing lehr. Preferably, the high-temperature exhaust gas from the tin bath is purified and filtered through an insulated pipe before being fed into the annealing lehr. The high-temperature protective gas in the tin bath enters the annealing lehr entirely, effectively utilizing the residual heat of the tin bath exhaust gas and recycling waste heat, thereby improving thermal energy utilization, saving energy, reducing the oxygen content in the annealing lehr, and extending the service life of the equipment. The annealing lehr is provided with several exhaust pipes, each of which is provided with a thermocouple on one side and a lifting curtain on the other side. The annealing lehr also includes a control unit that can precisely control the exhaust of each exhaust pipe, the raising and lowering of the lifting curtain, and the heating of the heating device according to the temperature requirements of different positions in the annealing lehr, thereby improving the three-dimensional temperature control accuracy of the annealing lehr.

[0020] The present invention also provides a method for manufacturing an optical element, which uses the glass formed body manufactured by the production process for display glass substrates to manufacture the optical element.

[0021] The present invention also provides an optical element, which is manufactured using the glass formed body manufactured by the production process for display glass substrates.

[0022] Beneficial effects of the present invention: The present invention carries out technological innovation in multiple processes of the display glass substrate production process, explores and utilizes the advantages of each process, conducts combination innovation research between the processes, and forms a display glass substrate production process with full utilization of resources, synergistic and complementary advantages, and organically unified production lines.

[0023] Specifically, the present invention calculates and observes the three-dimensional distribution patterns of bubbles of different sizes in the glass melt at different temperatures, at different positions in the melting furnace, and at different positions in the clarification channel, and through ingenious conception, designs an innovative combination device and production process of a partially heated melting furnace and a graded bubble removal and clarification device.

[0024] The multiple bubble removal structures of the graded bubble removal and clarification device enable glass liquid with a large number of bubbles of different diameters to flow through the structure. The lower connecting pipe section effectively separates the lower layer of glass liquid rich in smaller bubbles from the upper layer of glass liquid with larger bubbles. The upper layer of glass liquid with a large number of bubbles is blocked, and the bubbles gather, grow larger, float upward, and are then discharged from the exhaust pipe at the top, thus playing a role in selecting the glass liquid flow.

[0025] When the glass liquid with a small amount of bubbles flows through the reducer, the bubbles gather, grow larger, float up under the action of the inclined tube, and then are discharged in the next exhaust pipe. As the glass liquid continues to flow backward, it undergoes the process of gathering, growing larger, floating up, and being discharged many times, thus achieving full discharge of tiny bubbles in the glass liquid. The glass liquid is clarified efficiently by graded bubble removal, solving the problem of incomplete clarification of large-flow glass liquid.

[0026] After in-depth research, the applicant creatively discovered that by differentially controlling the heating temperatures of various parts of the partially heated melting furnace, a controllable distribution of the thermal field in the melting furnace can be achieved. By combining the partially heated melting furnace with a graded bubble removal and clarification device, a synergistic effect of the two process steps can be achieved: the graded bubble removal and clarification device is utilized to facilitate the characteristics of the process in which bubbles gather, grow, float, and discharge. On the premise of more completely removing bubbles from the molten glass, it becomes possible to control the distribution of the thermal field in the melting furnace, reasonably distribute heat, supply heat on demand, and save resources. At the same time, the partial heating melting furnace is utilized to more accurately control the distribution of the thermal field of the melt in different dimensions, thereby promoting the controllable generation of bubbles in the molten glass, changing the bubble distribution density of different laminar flows in the molten glass, and cleverly combining the structural design of the graded bubble removal and clarification device to achieve the purpose of improving the efficiency of bubble removal in the glass, greatly reducing the residual microbubbles in the glass plate, and improving the quality of the glass substrate. The combination of differentiated control of the partial heating melting furnace and the graded bubble removal and clarification device ensures a low residual microbubble rate and low energy consumption. On this basis, the flow rate and flow of the glass melt can be improved, the output can be increased, and large-scale production can be achieved.

[0027] The production process of the present invention also adopts an innovative tin bath device that can independently and controllably realize the differentiated supply of protective gas in different areas and the differentiated discharge of tin vapor and tin bath exhaust gas in different areas, thereby realizing precise control of the air intake and exhaust of the tin bath and precise control of the temperature field, maintaining the controllability and consistency of the protective gas and the environment to the greatest extent, reducing the residence time of tin vapor in any place in the bath, and improving product quality and the intelligent level of production.

[0028] The present invention cleverly allocates and fully utilizes the waste heat resources in the production line, utilizes the high-temperature protective gas of the tin bath in the annealing kiln, and integrates the transition roller table with the annealing kiln to realize the maximum possible utilization of the waste heat of the tin bath in the annealing kiln; and in order to fully utilize the waste heat of the tin bath, a plurality of exhaust pipes and lifting curtains are arranged on the top of the annealing kiln in the direction from the kiln entrance to the exit, and the exhaust and curtain lifting are controlled by the control unit, thereby intelligently controlling the curtain lifting, exhaust and heating according to the temperature requirements of different positions in the annealing kiln, thereby maximizing the utilization of the waste heat of the tin bath and accurately controlling the temperature of different areas in the annealing kiln, further improving the annealing effect, improving the energy utilization efficiency, extending the service life of the equipment, and further improving the level of intelligent and automated control.

[0029] The above-mentioned production process, unified allocation and utilization of resources, refined and precise control of processes, realize the organic coordination of various production process links, and better achieve the goal of green, intelligent, large-scale, high-quality, and high-generation advanced manufacturing of glass substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of a production line;

[0031] FIG2 is a front view of a partially heated melting furnace;

[0032] FIG3 is a left side view of a partially heated melting furnace;

[0033] Figure 4 is a right side view of a partially heated melting furnace;

[0034] FIG5 is a top view of a partially heated melting furnace;

[0035] Figure 6 is a cross-sectional view of a graded bubble removal and clarification device;

[0036] Figure 7 is a schematic structural diagram of the graded bubble removal and clarification device.

[0037] FIG8 is a schematic diagram of the connection between the clarification pipe section and the connecting pipe section.

[0038] Figure 9 is a schematic diagram of the tin bath structure.

[0039] Figure 10 is a partial enlarged view of the tin bath

[0040] Figure 11 is a top view of the tin bath top cover Specific implementation method:

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] As shown in FIG1 , an apparatus and process for producing display glass substrates includes a raw material mixing device 100 , a segmented heating melting furnace 200 , a graded bubble removal and clarification device 300 , a tin bath 400 , an annealing lehr 500 , and a cutting machine 600 . The structure of each device and the process conditions are described in detail below:

[0043] raw material:

[0044] The glass raw materials of the present invention are preferably alkali-free glass raw materials, comprising the following raw materials in percentage by weight:

[0045] 59-75% SiO2, 12-20% Al2O3, 6-12% B2O3, 0.5-8% MgO, 2-10% CaO, 0.5-8% SrO, 0.1-3% ZrO2, 0.5-6% P2O5, 0.06-1% SnO2;

[0046] Among them, SiO2+Al2O3 is 71-85%;

[0047] (MgO+CaO+SrO) / Al2O3 is 0.3-1;

[0048] The total amount of alkaline earth metal oxides is 3-15%;

[0049] B2O3 / (B2O3+ZrO2+P2O5) is 0.5-1.0;

[0050] (ZrO2+P2O5) / (MgO+CaO+SrO) is 0.1-1.0.

[0051] The glass composition preferably has a β-OH value of less than 0.5%, a boron volatility of less than 11%, and a thermal expansion coefficient of less than 39.5×10 -7 / ℃, Young's modulus higher than 80GPa, strain point higher than 700℃, melting temperature lower than 1662℃, and thermal shrinkage lower than 10ppm.

[0052] The above-mentioned raw materials do not contain toxic substances, are green and environmentally friendly, and are suitable for large-scale production of glass substrates for high-generation displays. By coordinating with other steps of the production process of the present invention, glass substrates for displays with characteristics such as high strain point, high Young's modulus, high hardness, high specific modulus, suitable thermal expansion coefficient, and low thermal shrinkage can be prepared.

[0053] Partially heated melting furnace:

[0054] The partially heated melting furnace of the present invention includes a control unit and a first melting unit and a second melting unit along the flow direction of the glass liquid. A furnace sill is arranged between the first melting unit and the second melting unit, and the furnace sill divides the melting furnace into the first melting unit and the second melting unit. A heating component is provided on the first melting unit, and another heating component is provided on the second melting unit. The control unit can control the heating of the first melting unit and the second melting unit respectively.

[0055] The preferred length-to-width ratio of the melting furnace is 2:1 to 3.5:1, and the furnace sill is set at 2 / 3 to 4 / 5 of the tank length.

[0056] The heating components used in the first melting part and the second melting part and the arrangement of each heating component can be the same or different. The heating components can be common heating components such as burners and heating electrodes; preferably, the melting furnace includes a bubbling device, which is arranged in the first melting part and in front of the kiln sill; further preferably, the first melting part and the second melting part are heated by a combined heating electrode and a burner; further preferably, the heating electrode can be a molybdenum electrode; further preferably, the first melting part, i.e., in front of the kiln sill, adopts a bottom-inserted rod-shaped molybdenum electrode combined with a burner for combustion heating, and the second melting part, i.e., behind the kiln sill, adopts a side-inserted plate-type molybdenum electrode, a side-inserted rod-type molybdenum electrode or a combination of side-inserted plate-type and rod-type molybdenum electrode, combined with a burner for combustion heating; further preferably, the flame ejected by the burner is horizontally distributed, the combustion gas is natural gas doped with 0-40% volume content of hydrogen, and the burners are divided into two rows and symmetrically distributed on the breast walls on both sides of the melting part.

[0057] The control part of the melting furnace of the present invention can control the first melting part and the second melting part by adopting a common temperature control method of temperature collection and control such as combined temperature collection and heating component heat output adjustment.

[0058] Preferably, the temperature difference between the first melting part and the second melting part is 5°C-40°C, preferably 10°C-30°C.

[0059] The temperature of the first melting part may be 1650-1690°C, preferably 1650-1680°C, and more preferably 1660-1670°C.

[0060] The temperature of the second melting part may be 1600-1650°C, preferably 1620-1640°C, and more preferably 1630-1640°C.

[0061] Specifically, as shown in Figures 2-5, the melting furnace 200 is divided into a first melting section 201 and a second melting section 202, which are connected in sequence along the direction of glass melt flow. A furnace sill is provided between the first and second melting sections. Preferably, the melting furnace includes a bubbling device 206, which is located in the first melting section, before the furnace sill. The melting furnace also includes a control unit for controlling the temperatures of the first and second melting sections.

[0062] The first melting section, located in front of the kiln sill, utilizes bottom-inserted rod-shaped molybdenum electrodes 203 in combination with burners 204 for combustion and heating. The second melting section, located behind the kiln sill, utilizes electrodes 205 in combination with burners 206 for combustion and heating. Electrode 205 can be a side-inserted plate-type molybdenum electrode, a side-inserted rod-type molybdenum electrode, or a combination of side-inserted plate and rod-type molybdenum electrodes. This configuration enhances the melting capacity of the first melting section, meeting the differentiated and precise temperature control requirements of the first and second melting sections, and ensuring the coordinated and unified high melting capacity and low energy efficiency of each melting section. To meet the requirements of environmental protection and low carbon emissions, the preferred burner combustion and heating method is oxygen-enriched natural gas mixed with 0-40% hydrogen by volume.

[0063] Grading defoaming and clarification device:

[0064] As shown in Figures 6-8, the graded bubble removal and clarification device 300 of the present invention includes a heating tube 302, a graded bubble removal and clarification channel, a cooling tube 307, a stirring barrel 308 and a feeding tube 309, which are connected in sequence as needed along the conveying direction of the glass liquid; the heating tube 302 and other sections of the graded bubble removal and clarification channel are provided with external heating devices, which can be electric heating or other common heating methods. Heat can be provided to the glass liquid through the external heating devices of each part.

[0065] The graded bubble removal and clarification channel preferably adopts a platinum channel, but other types of channels may also be adopted. In this embodiment, a platinum channel is adopted. The graded bubble removal and clarification channel includes several bubble removal structures for graded removal of bubbles in different depth areas of the glass liquid. The bubble removal structure includes a connecting pipe section 303 and a clarification pipe section 305 connected in sequence, and preferably also includes a deformable pipe section 304. The inner diameter of the connecting pipe section 303 is smaller than that of the clarification pipe section 305. The deformable pipe section 304 is used to connect the connecting pipe section 303 and the clarification pipe section 305. The connecting pipe section 303 with a small diameter is connected to the clarification pipe section 305 with a larger diameter through a reducing pipe, which effectively enhances the mechanical strength of the clarification pipe and can effectively support the pipe body at a higher temperature, reduce the creep deformation of the graded bubble removal and clarification channel as a whole under high temperature conditions, ensure its thermal stability under high temperature conditions, avoid the risk of high temperature deformation and collapse of the graded bubble removal and clarification channel, and extend the service life of the graded bubble removal and clarification channel.

[0066] During the transportation of the glass liquid, the height of the glass liquid level 301 inside the clarifying pipe section 305 is L0, the top surface height of the clarifying pipe section 305 is L1, and the top surface height of the connecting pipe section 303 is L2, and L1>L0>L2. In this way, when the glass liquid flows through the bubble discharge structure, the connecting pipe section 303 below the liquid level L0 can effectively separate the glass liquid rich in bubbles, and the upper layer of glass liquid with a large number of bubbles is blocked, and the bubbles gather, grow larger, float up, and are then discharged from the exhaust pipe 306 at the top, while the lower layer of glass liquid with relatively fewer and smaller bubbles can flow through, which plays the role of selecting the glass liquid flow.

[0067] The multi-stage setting of the bubble removal structure serves to separate different layers of glass liquid and realize graded bubble removal. Under the condition of the same length of bubble removal and clarification section, higher clarification efficiency can be obtained than that of the traditional platinum channel.

[0068] The inner diameters of the connecting pipe sections 303 on the various bubble removal structures are all different, and the inner diameters of the connecting pipe sections 303 gradually decrease along the direction of glass liquid transport. Referring to Figure 8 , a, b, and c represent, respectively, schematic diagrams of the docking of the clarification pipe sections 305 and the connecting pipe sections 303 of three bubble removal structures arranged along the direction of glass liquid transport, where H0 represents the diameter of the clarification pipe section 305, H1 represents the diameter of the connecting pipe section 303 of the first bubble removal structure, and H2 and H3 represent the diameters of the connecting pipe sections 303 of the second and third bubble removal structures, respectively, with H0 > H1 > H2 > H3.

[0069] The shaded part represents the partition 314 between different bubble removal structures. When bubbles of different sizes first pass through a, the bubbles in the upper layer are blocked by the shaded part, which increases the retention of bubbles. The bubbles gather, grow, float and are discharged. After the glass liquid containing small bubbles passes through H1, under the action of the inclined top tube with variable diameter, the small bubbles continue to gather and float. The bubbles in the middle layer gradually become bubbles in the upper layer. When passing through b, the bubbles in the upper layer are blocked by the shaded part, and the bubbles gather, grow, float and are discharged. The glass liquid containing a small number of bubbles in the lower layer flows through the small diameter tube H2 again. Similarly, when passing through the next bubble removal structure c, a small number of small bubbles gradually grow and float to the upper layer of glass liquid. When passing through H3, they are retained, gathered, grown and discharged. After the glass liquid with a large number of bubbles of different bubble diameters passes through multiple bubble removal structures, the bubbles are discharged in stages, thereby achieving a pure glass liquid flow.

[0070] One end of the connecting pipe section 303 is fixedly connected to the deformed pipe section 304, and the shape of the port where the deformed pipe section 304 is connected to the connecting pipe section 303 is consistent with the shape of the port of the connecting pipe section 303; the end of the deformed pipe section 304 away from the connecting pipe section 303 is fixedly connected to the clarification pipe section 305, and the shape of the port of this end is consistent with the shape of the port of the clarification pipe section 305; the bottom surfaces of the clarification pipe section 305, the connecting pipe section 303 and the deformed pipe section 304 are at the same horizontal height, and preferably, the top of the deformed pipe section 304 is set to be an inclined surface.

[0071] The clarification pipe section 305 is fixedly connected to a partition plate 314 at one end away from the deformed pipe section 304, and a through opening for docking with another connecting pipe section 303 is opened at the bottom of one side of the partition plate 314. The other connecting pipe section refers to the connecting pipe section on another adjacent bubble removal structure. The top surface of the clarification pipe section 305 close to the partition plate 314 is fixedly connected to an exhaust pipe 306, and the top end of the exhaust pipe 306 is bent downward; one end of the cooling pipe 307 is fixedly connected to the stirring barrel 308, and a stirring motor 310 is fixedly installed on the top of the stirring barrel 308. The output end of the stirring motor 310 is fixedly connected to a stirring rod, and the bottom of one side of the stirring barrel 308 is fixedly connected to a feeding pipe 309.

[0072] The inlet melt temperature entering the graded bubble removal and clarification channel is preferably 1590℃-1640℃, more preferably 1600℃-1630℃, and further preferably 1615℃-1630℃. The outlet melt temperature leaving the graded bubble removal and clarification channel is preferably 1570℃-1590℃, more preferably 1575℃-1585℃, and further preferably 1580℃-1585℃.

[0073] Tin bath:

[0074] Liquid crystal displays (LCDs) place extremely high demands on the microscopic waviness and surface roughness of glass substrates. To reduce warping, waviness, and the possibility of surface scratches, and to mitigate the impact of tin vapor condensation, the tin bath of the present invention precisely controls the supply of protective gas and the exhaust of tin vapor in separate zones, ensuring the consistency and purity of the environment in the tin bath.

[0075] Specifically, as shown in Figures 9-11, the glass tin bath includes a tin bath pool 401 and a tin bath top cover 406, which are sealed and installed. A top insulation layer 404 is provided between the tin bath pool 401 and the tin bath top cover 406. Several groups of space partitions 408 are fixedly installed on the inner side of the tin bath top cover 406. The space partitions 408 separate the interior of the tin bath top cover 406 into several top cover inner grooves 405, and the upper ends of the top cover inner grooves 405 are each installed with an air supply pipe 407. The protective gas supplied by the air supply pipe can enter the tin bath pool through the pores in the insulation layer. An exhaust slit 409 is opened on the breast wall above the tin bath pool 401, and several groups of exhaust pipes 414 are fixedly installed inside the exhaust slit 409. An exhaust baffle 413 is installed inside the exhaust slit 409 to divide the exhaust slit into multiple independent grooves. Each independent groove separated by the exhaust baffle is provided with at least one exhaust pipe 414. Air supply and exhaust control device, through which the flow of each air supply pipe and exhaust pipe can be controlled separately, and can be controlled by common joint working condition parameter collection, air supply and exhaust adjustment and other data collection and flow control control methods.

[0076] The glass liquid floats on the upper part of the tin liquid, and the protective gas is supplied and discharged between the tin bath pool 401 and the tin bath top cover 406 through the gas supply pipe 407 and the exhaust pipe 414, so that the protective gas flows in the tin bath top cover 406 and the tin bath pool 401.

[0077] The protective gas supplied through the gas supply pipe 407 is a mixture of nitrogen and hydrogen, and the ratio of nitrogen to hydrogen is (94-100):(0-6). Through gas supply control, the proportion of hydrogen in the nitrogen-hydrogen protective gas in the tin bath pool increases gradually from the front end to the back end of the tin bath, and the tin bath pressure is controlled at a positive pressure of 10 to 30 Pa higher than the standard atmospheric pressure. By using a combination of several gas supply pipes 407 and space partitions 408, several independent protective gas supply structures are formed on the upper part of the tin bath top cover 406, and the tin bath top cover 406 of the tin bath pool 401 is subjected to high-density zoning operation, and the protective gas volume of each zone is controlled with high precision, thereby achieving precise control of the temperature field control accuracy inside the tin bath pool 401, further improving the control ability of the thickness, warping and waviness of the glass plate, avoiding any oxygen or oxidizing substances from entering, thereby preventing oxidation of the tin liquid 411, and preventing the tin liquid from forming tin ash after oxidation and scratching the glass substrate; it can also adjust the gas supply and exhaust according to the change of the glass liquid temperature, achieve high-precision control of glass processing, and improve the processing quality of the glass; the precise control of gas supply and exhaust minimizes the retention of tin vapor anywhere in the tank, prevents the tin vapor from condensing in the gaps between the top insulation bricks and the breast wall insulation bricks, and reduces the probability of defects on the glass plate surface.

[0078] annealing:

[0079] The annealing furnace of the present invention is an ultra-thin glass annealing furnace. Preferably, the transition roller table between the tin bath and the annealing furnace is integrated with the annealing furnace, the transition roller table top cover is integrated with the annealing furnace top cover, and the annealing furnace bottom shell is integrated with the transition roller table bottom shell.

[0080] The high-temperature exhaust gas from the tin bath is preferably purified and filtered through an insulated pipe before being fed into the annealing lehr, allowing all the high-temperature protective gas in the tin bath to enter the annealing lehr. Alternatively, in addition to the high-temperature protective gas from the tin bath, other inert protective gases may be introduced into the annealing lehr as needed.

[0081] Preferably, a plurality of exhaust pipes are arranged on the top of the annealing furnace in the direction from the kiln entrance to the exit, a thermocouple is provided on one side of each exhaust pipe, and a lifting curtain is provided on the other side of the exhaust pipe. A heating device is provided in the annealing furnace, and an annealing furnace control unit is provided. The thermocouple, the lifting curtain, the heating device and the annealing furnace control unit form an electrical signal connection.

[0082] The temperature data of different areas in the annealing furnace are sent to the annealing furnace control unit through electric thermocouples. The annealing furnace control unit controls the appropriate height of the curtain according to these values, and at the same time controls the exhaust volume of the exhaust pipe and the heating device in the annealing furnace, thereby accurately controlling the temperature of different areas in the annealing furnace. At the same time, it effectively utilizes the thermal energy of the high-temperature protective gas in the tin bath, reduces energy consumption, and significantly reduces production costs.

[0083] The annealing lehr effectively utilizes the residual heat of the tin bath, reduces drafts in the annealing lehr, improves the three-dimensional temperature control accuracy of the annealing lehr, reduces the oxygen content in the annealing lehr, and increases the service life of the equipment.

[0084] The present invention also relates to a method for manufacturing an optical element, which uses the glass formed body manufactured by the production process for display glass substrates to manufacture the optical element.

[0085] The present invention also relates to an optical element, which is manufactured by using the glass formed body manufactured by the production process for display glass substrates.

[0086] Example

[0087] Example 1

[0088] The glass substrate raw material is configured according to the following weight percentages, which is an alkali-free glass substrate raw material: 62 wt% SiO2, 9 wt% B2O3, 17 wt% Al2O3, 4 wt% CaO, 2 wt% MgO, 3.8 wt% SrO, 1 wt% ZrO2, 1 wt% P2O5, and 0.2 wt% SnO2. The control unit controls the melting temperature of the first heating section 201 of the partial heating melting furnace 200 to be 1660°C, and the melting temperature of the second heating section 202 to be 1640°C. The pressure in the furnace is controlled to be a positive pressure of 5±0.5Pa higher than the standard atmospheric pressure. After the glass raw material melt is melted, it flows into the graded bubble removal and clarification device 300. The graded bubble removal and clarification device used in this embodiment is a platinum channel. The temperature of the melt entering the graded bubble removal and clarification device 300 is 1630°C, and the temperature of the melt leaving the graded bubble removal and clarification device 300 is 1580°C. After passing through the three-stage graded bubble removal structure, the glass raw material melt flows into the graded bubble removal and clarification device 300. After that, it enters the tin bath 400 for forming; the tin bath inlet temperature is 1300℃, the tin bath outlet temperature is 800℃, the tin bath protective gas requirements are as follows: nitrogen and hydrogen ratio is (94-100): (0-6), the hydrogen ratio increases gradually from the front end to the back end of the tin bath, the tin bath pressure is controlled at a positive pressure of 10 to 30Pa higher than the standard atmospheric pressure, and then the glass substrate enters the annealing furnace 500, the annealing furnace inlet temperature is 750℃, and the annealing furnace outlet temperature is 50℃ to ensure sufficient annealing of the glass plate; after annealing, cutting and other post-processing steps are carried out.

[0089] The molding methods of Examples 2-3 and Comparative Examples 1-2 are the same as those of Example 1, and the specific process parameters used are shown in Table 1 below.

[0090] Testing: The number of bubbles (pieces / kg), light transmittance, and the total unit energy consumption (kJ / kg) of the melting furnace and the graded bubble removal and clarification device of the glass substrates obtained in the examples and comparative examples were measured and counted.

[0091] The testing instruments used were: Bubble Detection Equipment: The ISRA flat glass defect inspection equipment was used to detect the number and distribution of bubbles, and the number of bubbles per unit weight was manually calculated; Transmittance Testing Equipment: A UV-Vis-NIR spectrophotometer (Model: Lambda 750 S) was used to measure the transmittance of the glass sheet in the visible light range. The final results are shown in the table below.

[0092] Table 1

[0093] The above performance and energy consumption tests and statistics clearly show that the technical solution of the present invention can achieve good technical effects, the prepared glass substrate has a higher light transmittance and a smaller number of bubbles, and the process can reduce unit energy consumption.

[0094] After extensive experiments and in-depth theoretical research, the applicant of the present invention analyzed multiple factors such as bubble generation density, bubble generation size, bubble rise rate, bubble absorption limit, and energy consumption limit in each melt laminar flow at different temperatures. This breakthrough led to the segmented temperature control of the glass melting furnace, which was combined with a graded clarification and bubble removal process. This allows for differential temperature control of different locations in the furnace based on the changing patterns of the temperature field of the glass melt at different flow locations and the optimal temperatures required by the glass melt at different flow locations for bubble removal, thereby increasing the precision and autonomy of temperature control. After fine temperature control and heating, the glass melt passes through a graded bubble removal and clarification device. Based on the three-dimensional distribution patterns of bubbles of different sizes within the graded bubble removal and clarification channel and the layer distribution patterns of the melt containing bubbles of different sizes, several bubble removal structures are used to separate bubbles of different sizes when the glass layer liquid containing bubbles of different diameters flows through the structure, or to eliminate them by combining separation with self-absorption, effectively separating and removing bubbles, achieving significant beneficial effects.

[0095] This production process has carried out in-depth research and careful selection in the links such as raw material ratio, melting in the melting furnace, defoaming in the clarification channel, tin bath forming, and annealing, achieving the organic synergy of various production process links, and realizing the organic unity of green, large-scale, intelligent, high-quality, and high-generation production, taking into account energy saving and consumption reduction with quality improvement, social benefits and economic benefits, and has good application prospects.

[0096] The above descriptions are merely preferred embodiments and examples of the present invention. The present disclosure is not limited to the specific details in the above embodiments and examples. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure. It should also be noted that the various specific technical features described in the above specific embodiments and examples can be combined in any suitable manner unless there is any contradiction. In order to avoid unnecessary repetition, the present disclosure will no longer describe various possible combinations. In addition, the various different embodiments and examples of the present disclosure can also be arbitrarily combined, and as long as they do not violate the ideas of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A device for producing display glass substrates, comprising a raw material mixing device, a partial heating melting furnace, a graded bubble removal and clarification device, a tin bath, an annealing furnace, a cutting and post-processing device, Features The partial heating melting furnace includes a control unit and a first melting unit and a second melting unit along the flow direction of the glass liquid. A heating component is provided on the first melting unit, and another heating component is provided on the second melting unit. The control unit can control the heating conditions of the first melting unit and the second melting unit respectively. The graded bubble removal and clarification device comprises a graded bubble removal and clarification channel, which comprises a plurality of bubble removal structures for gradedly removing bubbles in different depth areas of the glass liquid; the bubble removal structure comprises a connecting pipe section and a clarification pipe section, wherein the inner diameter of the connecting pipe section is smaller than that of the clarification pipe section. The control section of the partially heated melting furnace controls and adjusts the temperature of the first melting section and the temperature of the second melting section respectively to adapt to the degassing process of the graded degassing and clarification channel.

2. The device for producing a display glass substrate according to claim 1, characterized in that A kiln sill is arranged between the first melting part and the second melting part, the length-width ratio of the melting furnace is in the range of 2:1 to 3.5:1, and the kiln sill is arranged at 2 / 3 to 4 / 5 of the pool length.

3. The device for producing a display glass substrate according to claim 1 or 2, characterized in that The melting furnace includes a bubbling device, which is arranged in the first melting section and is located in front of the kiln sill; the first melting section and the second melting section are heated by a combined heating of heating electrodes and burners; the heating electrodes can be molybdenum electrodes; the flames ejected by the burners are horizontally distributed, the combustion gas is natural gas mixed with 0-40% volume content of hydrogen, and the burners are divided into two rows and symmetrically distributed on the breast walls on both sides of the melting section.

4. The device for producing a display glass substrate according to claim 1 or 2, characterized in that The first melting section adopts bottom-inserted rod-shaped molybdenum electrode combined with burner combustion heating, and the second melting section adopts side-inserted plate-type molybdenum electrode, side-inserted rod-type molybdenum electrode or side-inserted plate-type and rod-type combination molybdenum electrode, combined with burner combustion heating.

5. The device for producing a display glass substrate according to claim 1 or 2, characterized in that The graded degassing and clarifying device comprises a heating pipe, a graded degassing and clarifying channel, a cooling pipe, a stirring barrel and a feeding pipe which are connected in sequence. Each section of the heating pipe and the graded degassing and clarifying channel is provided with a heating device; one end of the cooling pipe is fixedly connected to the stirring barrel.

6. The device for producing a display glass substrate according to claim 1 or 2, characterized in that The bubble removal structure also includes a deformable pipe section for connecting the connecting pipe section and the clarifying pipe section.

7. The device for producing a display glass substrate according to claim 6, characterized in that The end of the clarification pipe section away from the deformation pipe section is fixedly connected to a partition plate, and a through hole for docking with another connecting pipe section is opened at the bottom of one side of the partition plate; the top surface of the clarification pipe section close to the partition plate is fixedly connected to an exhaust device.

8. The device for producing a display glass substrate according to claim 7, characterized in that The exhaust device is an exhaust pipe, and the top end of the exhaust pipe is bent downward.

9. The device for producing a display glass substrate according to claim 6, characterized in that The bottom surfaces of the clarification pipe section, the connecting pipe section and the deformation pipe section are at the same level, and the top of the deformation pipe section is arranged as an inclined surface.

10. The device for producing a display glass substrate according to claim 1 or 2, characterized in that When the graded degassing and clarification device is in use, the height of the glass liquid level inside the clarification pipe section is L0, the top surface height of the clarification pipe section is L1, and the top surface height of the connecting pipe section is L2, and L1>L0>L2.

11. The device for producing a display glass substrate according to claim 1 or 2, characterized in that The inner diameters of the connecting pipe sections on the plurality of bubble removal structures are different from each other, and the inner diameter of the connecting pipe section closer to the outlet direction of the graded bubble removal and clarification device is smaller.

12. The device for producing a display glass substrate according to claim 1 or 2, characterized in that: The tin bath comprises a tin bath pool and a tin bath top cover, a plurality of groups of space partitions are fixedly installed on the inner side of the tin bath top cover, the interior of the tin bath top cover is divided into a plurality of top cover inner grooves by the space partitions, and the upper ends of the top cover inner grooves are fixedly installed with air supply pipes, an exhaust slit is opened on the breast wall above the tin bath pool, a plurality of groups of exhaust pipes are fixedly installed inside the exhaust slit, an exhaust partition is installed inside the exhaust slit to divide the exhaust slit into a plurality of independent grooves, each of the above-mentioned independent grooves is provided with at least one exhaust pipe, and the air supply and exhaust control device can control the flow rate of each air supply pipe and the flow rate of each exhaust pipe separately, so as to autonomously and controllably realize the differentiated supply of protective gas in different areas and autonomously and controllably realize the differentiated discharge of tin vapor in different areas.

13. The device for producing a display glass substrate according to claim 1 or 2, characterized in that: The transition roller table between the tin bath and the annealing kiln is connected to the annealing kiln as a whole, the transition roller table top cover is connected to the annealing kiln top cover as a whole, the annealing kiln bottom shell is connected to the transition roller table bottom shell as a whole, and a number of exhaust pipes are arranged on the top of the annealing kiln in the direction from the kiln entrance to the exit, a thermocouple is provided on one side of each exhaust pipe, and a lifting curtain is provided on the other side of the exhaust pipe. A heating device is provided in the annealing kiln, and an annealing kiln control unit is provided. The thermocouple, the lifting curtain, the heating device and the annealing kiln control unit form an electrical signal connection, and the temperature data of different areas in the annealing kiln are sent to the annealing kiln control unit through the thermocouple. The annealing kiln control unit controls the appropriate height of the curtain to be raised and lowered according to these values, and at the same time controls the exhaust volume of the exhaust pipe and the heating device in the annealing kiln.

14. The device for producing a display glass substrate according to claim 13, characterized in that: The annealing furnace comprises an insulated pipeline with a purification and filtering device for conveying high-temperature waste gas from the tin bath into the annealing furnace, and a pipeline for introducing inert protective gas into the annealing furnace.

15. A process for producing a display glass substrate, which utilizes the device for producing a display glass substrate according to claims 1 to 14, comprising a raw material mixing step, a partial heating step, a graded bubble removal and clarification step, a tin bath forming step, an annealing step, a cutting and post-processing step, Features The partial heating melting furnace in the partial heating step includes a control unit and a first melting unit and a second melting unit along the flow direction of the glass liquid. A heating component is provided on the first melting unit, and another heating component is provided on the second melting unit. The control unit can control the heating of the first melting unit and the second melting unit respectively. The graded bubble removal and clarification device in the graded bubble removal and clarification step comprises a graded bubble removal and clarification channel, which comprises a plurality of bubble removal structures for gradedly removing bubbles in different depth areas of the glass liquid; the bubble removal structure comprises a connecting pipe section and a clarification pipe section, wherein the inner diameter of the connecting pipe section is smaller than that of the clarification pipe section. The control section of the partially heated melting furnace controls and adjusts the temperature of the first melting section and the temperature of the second melting section respectively to adapt to the degassing process of the graded degassing and clarification channel.

16. The process for producing a display glass substrate according to claim 15, characterized in that The temperature of the first melting portion is greater than the temperature of the second melting portion.

17. The process for producing a display glass substrate according to claim 16, characterized in that The temperature difference between the first melting part and the second melting part is 5°C-40°C, preferably 10°C-30°C.

18. The process for producing a display glass substrate according to claim 16, characterized in that The temperature of the first melting part may be 1650-1690°C, preferably 1650-1680°C, and further preferably 1660-1670°C. The temperature of the second melting part may be 1600-1650°C, preferably 1620-1640°C, and further preferably 1630-1640°C.

19. The process for producing a display glass substrate according to claim 15, characterized in that The ratio of nitrogen and hydrogen in the protective gas in the tin bath is (94-100): (0-6), and the ratio of hydrogen in the nitrogen-hydrogen protective gas increases gradually from the front end to the rear end, and the tin bath pressure is controlled at a positive pressure of 10 to 30 Pa higher than the standard atmospheric pressure.

20. The process for producing a display glass substrate according to claim 15, characterized in that The glass raw materials are preferably alkali-free glass raw materials, including the following raw materials in weight percentage: 59-75% SiO2, 12-20% Al2O3, 6-12% B2O3, 0.5-8% MgO, 2-10% CaO, 0.5-8% SrO, 0.1-3% ZrO2, 0.5-6% P2O5, 0.06-1% SnO2; Among them, SiO2+Al2O3 is 71-85%; (MgO+CaO+SrO) / Al2O3 is 0.3-1; The total amount of alkaline earth metal oxides is 3-15%; B2O3 / (B2O3+ZrO2+P2O5) is 0.5-1.0; (ZrO2+P2O5) / (MgO+CaO+SrO) is 0.1-1.

0.

21. A method for manufacturing an optical element, which uses the glass formed body manufactured by the process for producing a display glass substrate according to claims 15 to 20 to manufacture the optical element.

22. An optical element manufactured by using the glass formed body manufactured by the process for producing a display glass substrate according to claims 15 to 20.

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