Low-knot glass kiln and low-knot glass substrate production method

Abstract

The invention relates to a low-knot glass kiln and a low-knot glass substrate production method.The arch top of the glass kiln is provided with multiple sets of burning guns, the pool bottom of the glass kiln is provided with multiple sets of electrodes, and the burning guns are sequentially divided into a feeding set, a melting set and a cooling set from front to back; gas fuel is introduced into the burning guns of the feeding group and the melting group for burning and heating, and cooling air is introduced into the burning guns of the cooling group for cooling the surface layer of the molten glass; the electrodes are divided into two groups from front to back, and the current of the electrodes in the front group is greater than that of the electrodes in the rear group; under heating of the burning guns and the electrodes, hot spots of the glass kiln occur on the middle rear portion of the glass kiln, the burning guns of the cooling set are arranged behind the hot spots, and the coverage range is not smaller than one fourth of the area of the glass kiln. The burning guns are divided into the feeding group, the melting group and the cooling group, and an upper cooling process is added, so that the surface layer of molten glass at the rear part of the kiln is thickened and coagulated, and the knot defect is inhibited.

Description

Technical Field

[0001] The present application relates to the technical field of glass production, and in particular to a low-knot glass kiln and a low-knot glass substrate production method. Background Art

[0002] Due to the large output volume, high-generation TFT glass substrate production lines often have nodule defects, which seriously affect product quality and output. Among them, the nodule defect is formed in the process of melting glass in the glass kiln because the glass batch is not completely melted and homogenized or there is a surface layer of silicon-rich glass entering the production flow at the rear of the kiln. It is unmelted or drawn in the glass substrate, and the component detection shows that the silicon content is higher than the required glass component, which seriously affects the quality of the glass substrate and is a bad defect. In the prior art, there are some technical means to cause nodules. For example, Chinese Patent 202111251992.1 discloses a method for eliminating scum of medium-borosilicate pharmaceutical glass and a glass melting furnace structure. By introducing gas fuel for combustion, the surface temperature of the glass liquid is always controlled at a high temperature to avoid the glass liquid surface from being overcooled and scum forming, and to avoid the scum causing the glass liquid to nodule. However, it significantly increases the fuel consumption of glass melting, and because silicon is inevitable in the molten glass and excessively high temperatures can more easily lead to softening of the furnace wall, mixing silicon-rich elements into the molten glass, causing nodules, and therefore limited elimination effects. The input-output ratio of the technology is relatively low, severely limiting the economic benefits of high-generation TFT glass substrate production. Summary of the invention

[0003] The present application provides a low-knot glass kiln and a low-knot glass substrate production method to solve the problem in the prior art that kiln defects are prone to occur on high-generation TFT glass substrate production lines, affecting the quality of the glass, and the existing kiln elimination method has a low input-output ratio, which seriously limits the economic benefits of production.

[0004] According to a low-knot glass kiln provided by the present application, a plurality of groups of burning guns are arranged on the top of the glass kiln, and a plurality of groups of electrodes are arranged on the bottom of the glass kiln.

[0005] The burners are divided into a feeding group, a melting group and a cooling group from front to back. Gas fuel is introduced into the burners of the feeding group and the melting group for combustion and heating, and cooling air is introduced into the burners of the cooling group to cool the surface of the glass liquid.

[0006] The electrodes are divided into two groups from front to back, and the current of the electrodes in the front group is greater than the current of the electrodes in the back group;

[0007] The hot spot of the glass furnace occurs in the middle and rear part of the glass furnace. The burning gun of the cooling group is arranged behind the hot spot position and the coverage area is not less than one quarter of the area of ​​the glass furnace.

[0008] In some embodiments, the gas flow rate of the burner in each group is consistent; in the feed group, the natural gas flow rate of the burner is 3-6 Nm 3 / h; in the cooling group, the cooling air flow rate of the burner is 10~30Nm 3 / h.

[0009] In some embodiments, in the feed group, the natural gas flow rate of the burner is 4-5 Nm 3 / h; in the cooling group, the cooling air flow rate of the burner is 20~25Nm 3 / h.

[0010] In some embodiments, at the hot spot of the glass furnace, the bottom temperature of the molten glass is 1600°C to 1650°C, and the space temperature above the molten glass is 1500°C to 1600°C; after the hot spot of the glass furnace, the space temperature above the molten glass within the coverage area of ​​the cooling group is 1480°C to 1520°C.

[0011] In some embodiments, the crown of the glass furnace is provided with multiple sets of crown thermocouples, and the bottom of the glass furnace is provided with multiple sets of bottom thermocouples. The crown thermocouples and the bottom thermocouples are both provided at hot spots of the glass furnace.

[0012] In some embodiments, at the hot spot of the glass furnace, the bottom temperature of the molten glass is 1620°C to 1640°C, and the space temperature above the molten glass is 1530°C to 1570°C; after the hot spot of the glass furnace, the space temperature above the molten glass within the coverage area of ​​the cooling group is 1490°C to 1510°C.

[0013] In some embodiments, the currents of the electrodes in the front group are consistent, the currents of the electrodes in the rear group are consistent, and the total current of the electrodes in the front group accounts for 55% to 70%, and the total current of the electrodes in the rear group accounts for 30% to 45%.

[0014] In some embodiments, the total current of the electrodes in the front group accounts for 60% to 65%, and the total current of the electrodes in the rear group accounts for 35% to 40%.

[0015] In some embodiments, the ratio of the gas energy of the burner to the electric energy of the electrode is 0.5-0.85, wherein the thermal efficiency of the gas energy is 0.65 and the thermal efficiency of the electric energy is 0.9.

[0016] In some embodiments, six groups of burners are evenly distributed on the top of the glass kiln, and six groups of electrodes are evenly distributed on the bottom of the glass kiln, and the positions of the burners and the electrodes correspond one to another; the feeding group, melting group and cooling group include one group of burners, three groups of burners and two groups of burners, respectively, and the electrodes are divided into two groups, front and back.

[0017] According to another aspect of the present application, a method for producing a low-knot glass substrate is provided, which is applied to the above low-knot glass furnace, comprising:

[0018] In the front middle of the glass furnace, the glass material is heated by the feeding group firing gun, the melting group firing gun and the front group electrode to fully melt the glass material and reach the preset hot spot temperature;

[0019] At the rear of the glass furnace, the bottom of the pool is heated by the rear group of electrodes to keep the glass liquid warm, and the surface of the glass liquid is cooled by the cooling group of torches, so that the surface of the glass liquid stagnates and cannot flow out of the glass furnace;

[0020] The clarified glass liquid flowing out of the glass furnace is transported to the production room for glass substrate production.

[0021] By applying the technical solution of the present application, a plurality of groups of burners are provided on the crown of a low-knot glass kiln, a plurality of groups of electrodes are provided on the bottom of the glass kiln, and the burners are divided into a feeding group, a melting group and a cooling group from front to back. Gas fuel is introduced into the burners of the feeding group and the melting group for combustion heating, and cooling air is introduced into the burners of the cooling group to cool the surface of the glass liquid; the electrodes are divided into two groups from front to back, and the current of the electrodes in the front group is greater than the current of the electrodes in the rear group; under the heating of the burners and the electrodes, the hot spot of the glass kiln occurs in the middle and rear part of the glass kiln, and the burners of the cooling group are arranged behind the hot spot position, and the coverage area is not less than one quarter of the area of ​​the glass kiln. The glass kiln of the present application is provided with a top burner and a bottom electrode, which can fully heat the molten glass to fully melt and homogenize it, thereby reducing the probability of nodules caused by uneven glass liquid; at the same time, on this basis, the present application adds an upper cooling process, dividing the burner into a feeding group, a melting group and a cooling group, wherein the feeding group and the melting group maintain the heating effect unchanged, while the cooling group is changed to introduce cooling air, and the coverage area is not less than one-quarter of the area of ​​the glass kiln, thereby effectively reducing the surface temperature of the glass liquid at the rear of the glass kiln, causing the silicon-rich components on its surface to become viscous and stagnant, thereby being unable to flow out of the glass kiln into the production flow, and no nodule defects will be generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0024] Figure 1A schematic structural diagram of a low-knot glass furnace according to an embodiment of the present application is shown;

[0025] Figure 2 A schematic flow chart of a method for producing a low-knot glass substrate according to an embodiment of the present application is shown;

[0026] The above drawings include the following reference numerals:

[0027] 10. Burning gun group; 11. Feeding group; 12. Melting group; 13. Cooling group; 20. Electrode group; 21. Front group; 22. Rear group; 30. Top thermocouple; 40. Bottom thermocouple. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0030] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] Figure 1 An embodiment of a low-knot glass furnace of the present application is schematically shown.

[0034] like Figure 1 As shown, the present application discloses a low-knot glass furnace, the crown of which is provided with multiple groups of burners (i.e., burner group 10), and the bottom of the glass furnace is provided with multiple groups of electrodes (i.e., electrode group 20). Among them, the burner group 10 is divided into a feeding group 11, a melting group 12, and a cooling group 13 from front to back, and gas fuel is introduced into the burners of the feeding group 11 and the melting group 12 for combustion heating; cooling air is introduced into the burners of the cooling group 13 to cool the surface of the glass liquid. The electrode group 20 is divided into two groups from front to back, and the electrode current in the front group 21 is greater than the electrode current in the rear group 22. The hot spot of the glass furnace (i.e., the position with the highest temperature in the glass furnace) occurs in the middle and rear part of the glass furnace, and the burners of the cooling group 13 are arranged behind the hot spot position, and the coverage range is not less than one-fourth of the area of ​​the glass furnace.

[0035] Through the above-mentioned structural design, the glass kiln in the embodiment of the present application is provided with a top burner and a bottom electrode, which can fully heat the glass liquid to make it fully melted and homogenized, thereby reducing the probability of nodules caused by uneven glass liquid; at the same time, on this basis, the present application adds an upper cooling process, and divides the burner into a feeding group 11, a melting group 12 and a cooling group 13, wherein the feeding group 11 and the melting group 12 maintain the heating effect unchanged, while the cooling group 13 is changed to introduce cooling air, and the coverage area is not less than one-quarter of the area of ​​the glass kiln, thereby effectively reducing the surface temperature of the glass liquid at the rear of the glass kiln, making its surface become viscous and stagnant, so that it cannot flow out of the glass kiln into the production flow, and no nodule defects will occur.

[0036] In the production of glass melt furnaces, the upper layer of glass melt in the glass melt is subjected to high temperature, and the volatile components in the upper layer of the glass melt slowly evaporate from the glass melt, while the silicon component in the glass melt is not volatile, so the silicon content of the glass melt in the upper layer of the furnace will gradually increase, and eventually form a silicon-rich layer that is inconsistent with the required composition of the glass substrate. The silicon-rich layer is more viscous than the clarified glass melt, and if it enters the production flow, it will form a nodule defect. Although there are processes in the prior art to further heat the silicon-rich layer to promote reflux and homogenization, the input-output ratio is not worth the cost, and because the enrichment of silicon components in the glass melt is inevitable, the nodules and the effect are not ideal. The present application proposes a set of effective nodule process countermeasures by analyzing the nodule formation mechanism and main nodule components. The method of increasing upper cooling is adopted, and a cooling group 13 burner is set at the rear of the glass kiln. The cooling group 13 burner is used to transport cooling air to cool the upper glass liquid, thereby making the upper silicon-rich layer of glass liquid more viscous, causing it to stagnate and not flow, preventing it from entering the production flow, and thus no nodule defects will be generated again.

[0037] In some embodiments of the present application, the glass furnace is like a house, with two burners forming a pair, and each pair of burners is symmetrically distributed on both sides of the glass furnace. In order to ensure that the glass liquid on both sides of the glass furnace is melted evenly, the gas volume of the left and right burners of each pair of burners is the same, and the gas volume of each pair of burners can be adjusted to adjust the temperature of the corresponding position of the glass furnace. The fluxing electrodes are also distributed on both sides of the furnace like the burners, with the left and right electrodes forming a group. The left and right electrodes in each group are connected through the glass liquid to form a loop, thereby heating the glass liquid. The glass liquid is both a conductor and a heat receiving body. Each group of electrodes is set separately, and the heating amount can be increased by increasing the current.

[0038] In some embodiments of the present application, the gas flow rates of the burners in the feed group 11, the melting group 12 and the cooling group 13 are different, while the gas flow rates of the burners in each group are the same. The feed group 11 and the melting group 12 use natural gas as the fuel gas. In the feed group 11, the natural gas flow rate of the burner is 3-6 Nm 3 / h, in the melting group 12, the natural gas flow rate of the burner is adjusted according to the detected top temperature. In the cooling group 13, the cooling air flow rate of the burner is 10~30Nm 3 / h.

[0039] In addition, in some preferred embodiments of the present application, in the feed group 11, the natural gas flow rate of the burner is 4-5 Nm 3 / h; in cooling group 13, the cooling air flow rate of the burner is 20~25Nm 3 / h.

[0040] like Figure 1As shown, the glass furnace generally adds glass batch materials from the top, and the front end is the feeding area and the middle part is the melting area. Since there are many materials in the feeding area and the temperature is relatively low, it is necessary to burn and heat up quickly to make the glass material melt quickly, so as to fully mix and homogenize and clarify in the melting area. In the embodiment of the present application, through the above-mentioned fuel control of the feeding group 11 burner and the control of the cooling air volume of the cooling group 13 burner, the glass liquid in the front feeding area can be quickly melted and homogenized, and the silicon-rich surface layer of the glass in the rear flow area can be cooled, thereby effectively reducing the uneven melting of the glass material and the nodule defects caused by the silicon-rich layer mixing into the production flow. In addition, through the above-mentioned gas flow control ratio, the pressure of the space before and after the glass furnace can also be balanced, so that the introduction of low-temperature air at the rear end will not affect the gas flow at the front end, thereby ensuring the stable and reliable combustion of the front heating group and melting group burners. In addition, the present application introduces cooling air into the air above the surface of the glass liquid at the rear end of the kiln, which can also reduce the volatilization of light components in the glass liquid at the rear end, thereby reducing the waste of glass liquid components and slowing down the silicon element enrichment phenomenon, further avoiding the problem of nodules in the glass liquid.

[0041] In some embodiments of the present application, Figure 1 As shown, the crown of the glass furnace is provided with a plurality of crown thermocouples 30, and the bottom of the glass furnace is provided with a plurality of bottom thermocouples 40. The crown thermocouples 30 are used to measure the temperature of the upper space of the furnace, and the bottom thermocouples 40 are used to measure the temperature of the glass liquid at the bottom of the furnace. The crown thermocouples 30 and the bottom thermocouples 40 are both provided at the hot spots of the glass furnace, so that the temperature in the glass furnace can be accurately monitored from both ends.

[0042] In some embodiments of the present application, at the hot spot of the glass furnace, the bottom temperature of the glass liquid is 1600℃~1650℃, and the temperature of the space above the glass liquid is 1500℃~1600℃. After the hot spot position of the glass furnace, the temperature of the space above the glass liquid within the coverage range of the cooling group 13 is 1480℃~1520℃. Among them, the higher the temperature of the glass liquid, the better the melting and homogenization effect, but its temperature also has an upper limit. Too high a temperature will aggravate the erosion of the glass furnace, causing the furnace wall of the glass furnace to soften and mix into the glass liquid, causing the risk of nodules. Therefore, the present application reasonably designs the hot spot temperature of the glass liquid so that the glass liquid can be fully melted to meet the requirements of homogenization and mixing, and will not erode the softened furnace wall, avoiding the separation of furnace wall components and mixing into the glass liquid. At the same time, the present application strictly controls the temperature of the space above the rear of the furnace, so that it is in contrast with the hot spot temperature of the melting zone at the front end, and can reliably cool the top silicon-rich layer in the flow production area, so that it will stagnate and will not mix into the production flow and flow out of the furnace.

[0043] In addition, in some preferred embodiments of the present application, at the hot spot of the glass furnace, the bottom temperature of the glass liquid is 1620°C to 1640°C, and the temperature of the space above the glass liquid is 1530°C to 1570°C; after the hot spot of the glass furnace, the temperature of the space above the glass liquid within the coverage of the cooling group 13 is 1490°C to 1510°C. By further setting the preferred parameters, the nodule rate can be strictly controlled to reduce the risk of product production and improve the quality of the glass substrate.

[0044] In some embodiments of the present application, in the front and rear groups of electrodes, the currents of the electrodes in the front group 21 are consistent, and the currents of the electrodes in the rear group 22 are consistent, and the total current of the electrodes in the front group 21 accounts for 55% to 70%, and the total current of the electrodes in the rear group 22 accounts for 30% to 45%. The coverage of the electrodes in the front group 21 involves the feeding area and melting area of ​​the glass kiln. The energy required in this area is very large. If the glass material in the front of the glass kiln is not melted well, raw materials will be formed in the area where the electrodes in the rear group 22 are located, and the raw materials will form nodules due to poor dissolution when entering the rear process. Therefore, the electrode current of the front group 21 must be set higher to meet the melting requirements of the front of the kiln.

[0045] In addition, in some preferred embodiments of the present application, the total electrode current in the front group 21 accounts for 60% to 65%, and the total electrode current in the rear group 22 accounts for 35% to 40%. Such a ratio can better control the glass melting and insulation process.

[0046] In some embodiments of the present application, in the upper and lower heating energy ratio, the ratio of the gas energy of the burner to the total electric energy of the electrode is set to 0.5-0.85, wherein the thermal efficiency of the gas energy is calculated as 0.65, and the thermal efficiency of the electric energy is calculated as 0.9. Among them, the proportion of gas energy is relatively low, which can reduce the impact of the post-combustion products of natural gas and other gases (such as water, etc.) on the glass liquid and the glass furnace, which helps to ensure the quality of the glass liquid and increase the service life of the glass furnace.

[0047] In some embodiments of the present application, Figure 1As shown, the top of the glass furnace is evenly distributed with six groups of burners, and the bottom of the glass furnace is evenly distributed with six groups of electrodes, and the positions of the burners and electrodes correspond one to another. The feeding group 11, the melting group 12 and the cooling group 13 respectively include one group of burners, three groups of burners and two groups of burners. The electrodes are divided into two groups, front and back. Thus, the feeding group 11 and the melting group 12 cover two-thirds of the area of ​​the glass furnace, the cooling group 13 covers one-third of the area of ​​the glass furnace, and the hot spot position of the glass furnace is generated at two-thirds of the glass furnace. In some other embodiments of the present application, the burners can also be arranged in other numbers, but the coverage area of ​​the cooling group 13 burners must be controlled to be not less than one-fourth of the area of ​​the glass furnace to ensure the thickening and stagnating effect of the silicon-rich layer on the surface of the glass liquid at the rear of the furnace, thereby effectively reducing the outflow of the silicon-rich layer and improving the quality of the glass substrate.

[0048] According to another aspect of the present application, the present application also discloses a method for producing a low-nodule glass substrate, which is applied to the low-nodule glass furnace shown in the above embodiments, and the method comprises:

[0049] Step S210, in the front middle of the glass furnace, the glass material is heated by the burning gun of the feeding group 11, the burning gun of the melting group 12 and the front group 21 electrodes to fully melt the glass material and reach a preset hot spot temperature.

[0050] Step S220, at the rear of the glass furnace, the bottom of the pool is heated by the rear group 22 electrodes to keep the glass liquid warm, and at the same time, the surface of the glass liquid is cooled by the cooling group 13 torches, so that the surface of the glass liquid is stagnant and cannot flow out of the glass furnace.

[0051] Step S230, the clarified glass liquid is drawn out from the lower part of the glass furnace and transferred to the production room for glass substrate production.

[0052] In some embodiments of the present application, in step S210, the gas flow rates of the burners in the feeding group 11, the melting group 12 and the cooling group 13 are different, while the gas flow rates of the burners in each group are consistent. The feeding group 11 and the melting group 12 use natural gas as the fuel gas. The natural gas flow rate of the burner in the feeding group 11 is 3-6 Nm 3 / h. The cooling air flow rate of the burner in cooling group 13 is 10~30Nm 3 In some preferred embodiments, the natural gas flow rate of the burner in the feed group 11 is 4-5 Nm 3 / h; the cooling air flow rate of the burner in cooling group 13 is 20~25Nm 3 / h.

[0053] In some embodiments of the present application, in step S210, at the hot spot of the glass furnace, the bottom temperature of the glass liquid is controlled to be 1600°C to 1650°C, and the temperature of the space above the glass liquid is controlled to be 1500°C to 1600°C. In step S220, after the hot spot of the glass furnace, the temperature of the space above the glass liquid within the coverage of the cooling group 13 is controlled to be 1480°C to 1520°C. In some preferred embodiments, in step S210, at the hot spot of the glass furnace, the bottom temperature of the glass liquid is controlled to be 1620°C to 1640°C, and the temperature of the space above the glass liquid is controlled to be 1530°C to 1570°C; in step S220, after the hot spot of the glass furnace, the temperature of the space above the glass liquid within the coverage of the cooling group 13 is controlled to be 1490°C to 1510°C.

[0054] In some embodiments of the present application, in the front and rear groups of electrodes, the currents of the electrodes in the front group 21 are consistent, and the currents of the electrodes in the rear group 22 are consistent, and the total current of the electrodes in the front group 21 accounts for 55% to 70%, and the total current of the electrodes in the rear group 22 accounts for 30% to 45%. In some preferred embodiments, the total current of the electrodes in the front group 21 accounts for 60% to 65%, and the total current of the electrodes in the rear group 22 accounts for 35% to 40%.

[0055] In some embodiments of the present application, in the upper and lower end heating energy ratio, the ratio of the gas energy of the burner to the total electric energy of the electrode is set to 0.5-0.85, wherein the thermal efficiency of the gas energy is calculated as 0.65 and the thermal efficiency of the electric energy is calculated as 0.9.

[0056] As described above, this application proposes a set of effective process countermeasures by analyzing the nodule generation mechanism and nodule composition, which is mainly reflected in the setting of kiln process parameters. As shown in Table 1 below, the comparison shows the nodule reduction effect of the glass substrate after the process improvement of this application.

[0057] Table 1 Comparison of the nodule effect of the embodiment of the present application and the applicant's existing process before improvement

[0058]

[0059] In summary, the low-nodule glass kiln of the present application has multiple groups of burners on its top and multiple groups of electrodes on the bottom. The burners are divided into a feeding group, a melting group and a cooling group from front to back. Gas fuel is introduced into the burners of the feeding group and the melting group for combustion and heating, and cooling air is introduced into the burners of the cooling group to cool the surface of the glass liquid; the electrodes are divided into two groups from front to back, and the current of the electrodes in the front group is greater than the current of the electrodes in the rear group; under the heating of the burners and the electrodes, the hot spot of the glass kiln occurs in the middle and rear part of the glass kiln, and the burners of the cooling group are arranged behind the hot spot position, and the coverage area is not less than one quarter of the area of ​​the glass kiln. The glass kiln of the present application is provided with a top burner and a bottom electrode, which can fully heat the molten glass to fully melt and homogenize it, thereby reducing the probability of nodules caused by uneven glass liquid; at the same time, on this basis, the present application adds an upper cooling process, dividing the burner into a feeding group, a melting group and a cooling group, wherein the feeding group and the melting group maintain the heating effect unchanged, while the cooling group is changed to introduce cooling air, and the coverage area is not less than one-quarter of the area of ​​the glass kiln, thereby effectively reducing the surface temperature of the glass liquid at the rear of the glass kiln, causing the silicon-rich components on its surface to become viscous and stagnant, thereby being unable to flow out of the glass kiln into the production flow, and no nodule defects will be generated.

[0060] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A low-knot glass furnace, wherein the top of the glass furnace is provided with multiple sets of burning guns, and the bottom of the glass furnace is provided with multiple sets of electrodes, characterized in that: The burners are divided into a feeding group (11), a melting group (12) and a cooling group (13) from front to back. Gas fuel is introduced into the burners of the feeding group (11) and the melting group (12) for combustion heating, and cooling air is introduced into the burners of the cooling group (13) for cooling the surface of the glass liquid. The electrodes are divided into two groups from front to back, and the current of the electrodes in the front group (21) is greater than the current of the electrodes in the rear group (22); The hot spot of the glass furnace occurs in the middle and rear part of the glass furnace, and the burner of the cooling group (13) is arranged behind the hot spot position, and the coverage area is not less than one quarter of the area of ​​the glass furnace.

2. The low-knot glass furnace according to claim 1, characterized in that: The gas flow rate of the burner in each group is consistent; in the feeding group (11), the natural gas flow rate of the burner is 3-6Nm 3 / h; in the cooling group (13), the cooling air flow rate of the burner is 10 to 30 Nm 3 / h.

3. The low-knot glass furnace according to claim 2, characterized in that: In the feed group (11), the natural gas flow rate of the burner is 4-5 Nm 3 / h; in the cooling group (13), the cooling air flow rate of the burner is 20 to 25 Nm 3 / h.

4. The low-knot glass furnace according to claim 1, characterized in that: The crown of the glass furnace is provided with a plurality of crown thermocouples (30), and the bottom of the glass furnace is provided with a plurality of bottom thermocouples (40). The crown thermocouples (30) and the bottom thermocouples (40) are both provided at hot spots of the glass furnace.

5. The low-knot glass furnace according to claim 1, characterized in that: At the hot spot of the glass furnace, the bottom temperature of the glass liquid is 1600°C to 1650°C, and the space temperature above the glass liquid is 1500°C to 1600°C; after the hot spot of the glass furnace, the space temperature above the glass liquid within the coverage area of ​​the cooling group (13) is 1480°C to 1520°C.

6. The low-knot glass furnace according to claim 1, characterized in that: Among the electrodes, the currents of the electrodes in the front group (21) are consistent, the currents of the electrodes in the rear group (22) are consistent, and the total current of the electrodes in the front group (21) accounts for 55% to 70%, while the total current of the electrodes in the rear group (22) accounts for 30% to 45%.

7. The low-knot glass furnace according to claim 6, characterized in that: The total electrode current in the front group (21) accounts for 60% to 65%, and the total electrode current in the rear group (22) accounts for 35% to 40%.

8. The low-knot glass furnace according to claim 1, characterized in that: The ratio of the gas energy of the burner to the total electric energy of the electrode is 0.5-0.85, wherein the thermal efficiency of the gas energy is 0.65 and the thermal efficiency of the electric energy is 0.

9.

9. The low-knot glass furnace according to any one of claims 1 to 8, characterized in that: The top of the glass furnace is evenly distributed with six groups of burners, and the bottom of the glass furnace is evenly distributed with six groups of electrodes, and the positions of the burners and the electrodes correspond to each other one by one; the feeding group (11), the melting group (12) and the cooling group (13) respectively include one group of burners, three groups of burners and two groups of burners, and the electrodes are divided into two groups, front and back.

10. A method for producing a low-knot glass substrate, applied to the low-knot glass furnace according to any one of claims 1 to 9, characterized in that: include: In the front middle of the glass furnace, the glass material is heated by the feeding group (11) burner, the melting group (12) burner and the front group (21) electrode to fully melt the glass material and reach a preset hot spot temperature; At the rear of the glass furnace, the bottom of the pool is heated by the rear group (22) of electrodes to keep the glass liquid warm, and at the same time, the surface of the glass liquid is cooled by the cooling group (13) of torches, so that the surface of the glass liquid is stagnant and cannot flow out of the glass furnace; The clarified glass liquid is drawn out from the bottom of the glass furnace and transferred to the production room for glass substrate production.

Images