Method for avoiding liquid level diving of platinum channel in liquid crystal glass production

Abstract

The invention discloses a method for avoiding liquid level diving of a platinum channel in liquid crystal glass production, and relates to the technical field of glass production. According to the technical scheme, the method comprises the following steps: S1, after molten glass enters a lifting section of a platinum channel, carrying out heat preservation on the molten glass; s2, after the molten glass enters the horizontal section of the platinum channel, heating the molten glass to 1600-1610 DEG C; s3, the molten glass enters a first cooling section of the platinum channel for cooling, and the first cooling section is provided with a liquid level meter. The glass liquid entering the lifting section of the platinum channel is subjected to heat preservation, so that the situation that the solubility of the gas is reduced after the temperature of the glass liquid is increased, the gas is separated out and then gathered into bubbles, and the bubbles are gathered into large bubbles on the upper edge of the horizontal part of the outlet end of the lifting section of the platinum channel is avoided; and the sudden change of the detected liquid level, namely the liquid level diving phenomenon, is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of glass production, and in particular to a method for preventing liquid level diving in a platinum channel during production of liquid crystal glass. Background Art

[0002] In the manufacturing process of liquid crystal electronic glass substrates, the kiln melts the batch materials into molten glass. The clarified molten glass is sent to the platinum channel for further clarification and cooled to a temperature suitable for molding requirements.

[0003] The batch material is melted in the kiln to form glass liquid. Under the action of high temperature, the gas solubility decreases, gas is precipitated, and gathered into bubbles, escaping from the surface of the glass liquid. The clarified glass liquid is discharged from the bottom of the kiln and enters the platinum channel and is heated again. At this time, the gas solubility of the glass liquid is further reduced, and gas continues to be precipitated and gathered into bubbles. Under the action of the platinum channel lifting section, the glass liquid is lifted to the free liquid surface and enters the horizontal section of the platinum channel. At this time, the glass liquid completely fills the platinum channel lifting section, but is not completely filled in the platinum channel horizontal section, and the upper part is a gas space. Considering the structural rationality and structural strength, a small part of the lifting section is designed to be in a horizontal state.

[0004] When the glass liquid enters the platinum channel from the kiln and heats up again, the reduction of gas solubility causes gas precipitation and gathers into bubbles. The generated bubbles rise under the drive of the glass liquid and the upward buoyancy, and gather into a super-large bubble (cavity) at the horizontal part of the outlet of the lifting section. When the bubble is large enough, part of it escapes into the horizontal section of the platinum channel, and breaks on the surface of the glass liquid, and is discharged into the gas space above the horizontal section of the platinum channel. In this process, due to the rupture of the super-large bubble, the glass liquid in the platinum channel refluxes, and the level gauge for detecting the glass liquid level in the production of liquid crystal glass substrates is located in the first cooling section of the platinum channel near the horizontal section of the platinum channel, and has high precision and is easily affected. Therefore, the reflux of the glass liquid can easily cause the detection liquid level to drop suddenly, and then quickly rise again, which is called liquid level diving in production. During the liquid level diving process, the DCS system controls the rapid increase and decrease of the feeding rate, which is not conducive to process stability and improving the quality of glass products. Therefore, a method is needed to eliminate bubbles from gathering into a super large bubble at the horizontal part of the outlet end of the lifting section, so as to prevent the detection of a sudden change in the liquid level, stabilize the liquid level, and thus improve the quality of glass products. Summary of the invention

[0005] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art and provide a method for preventing liquid level diving in a platinum channel during the production of liquid crystal glass, by insulating the glass liquid entering a platinum channel lifting section, so as to prevent the solubility of gas from decreasing after the glass liquid is heated, thereby preventing gas from precipitating, and then gathering into bubbles and gathering into large bubbles on the upper edge of the horizontal part at the outlet end of the platinum channel lifting section, thereby avoiding the occurrence of a sudden change in the detected liquid level, i.e., a liquid level diving phenomenon.

[0006] The technical solution of the present invention is:

[0007] A method for preventing a liquid level dive in a platinum channel during production of liquid crystal glass comprises the following steps:

[0008] After the S1 glass liquid enters the platinum channel lifting section, the glass liquid is kept warm;

[0009] After the S2 glass liquid enters the horizontal section of the platinum channel, the glass liquid is heated to 1600-1610°C;

[0010] The S3 glass liquid enters the first cooling section of the platinum channel for cooling, and the first cooling section is provided with a liquid level meter.

[0011] Preferably, in step S1, the temperature of the molten glass at the inlet of the platinum channel lifting section is lower than the temperature of the molten glass at the outlet of the platinum channel lifting section, and the temperature difference is less than 5°C.

[0012] Preferably, in step S1, the insulation time is 2-3 hours.

[0013] Preferably, in step S1, the temperature of the molten glass at the entrance of the platinum channel lifting section is 1500-1510°C.

[0014] Preferably, in step S2, the heating rate is 20-30°C / h and the heating time is 3-5h.

[0015] Preferably, in step S3, the glass liquid is cooled to 1500-1510°C.

[0016] Preferably, in step S3, the cooling rate is 10-20°C / h and the cooling time is 3-5h.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention heats the glass liquid entering the platinum channel lifting section to avoid the reduction of gas solubility after the glass liquid is heated, thereby preventing the gas from being precipitated, and then gathering into bubbles and gathering into large bubbles on the upper edge of the horizontal part of the outlet end of the platinum channel lifting section. After the generation of large bubbles is avoided, the bubble bursting will not occur, thereby avoiding the occurrence of a sudden change in the detected liquid level, i.e., the liquid level diving phenomenon, and stabilizing the feeding state and the liquid level. At the same time, the glass liquid is heated in the horizontal section of the platinum channel to obtain a high-temperature glass liquid with low gas solubility, and gas is precipitated in this process, gathered into bubbles, and then escaped from the glass liquid. The high-temperature glass liquid with low gas solubility is cooled again, and its gas solubility increases, absorbing visible bubbles in the glass liquid, thereby eliminating the visible bubbles, reducing the bubble defect rate, and improving the quality of glass products. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] In the figure, 1. platinum channel lifting section; 2. platinum channel horizontal section; 3. platinum channel first cooling section; 4. liquid level gauge; 5. free liquid surface. DETAILED DESCRIPTION

[0021] In order to enable persons skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0022] like Figure 1 As shown, the platinum channel includes a platinum channel lifting section 1, a platinum channel horizontal section 2 and a platinum channel first cooling section 3, wherein the inlet and outlet ends of the platinum channel lifting section 1 are both in a horizontal state, and the middle section is a continuously rising channel; the platinum channel horizontal section 2 is in a horizontal state, and there is a gas space on its upper part, the glass liquid is at a free liquid surface 5 and the free liquid surface 5 is higher than the highest point of the platinum channel lifting section 1; the liquid level meter 4 is located in the platinum channel first cooling section 3, installed at the GL liquid level measuring hole, and detects the height of the free liquid surface 5.

[0023] The initial glass liquid from the kiln process enters the platinum channel through the entrance of the platinum channel lifting section 1, and is insulated by the heating circuit of the platinum channel lifting section 1, so that the temperature difference between the glass liquid at the outlet of the platinum channel lifting section 1 and the initial glass liquid is less than 5°C, and the insulation time is 2-3h; then the glass liquid enters the platinum channel horizontal section 2, and is heated by the heating circuit of the platinum channel horizontal section 2, and is heated to 1600-1610°C at a heating rate of 20-30°C / h, and the heating time is 3-5h; finally, the glass liquid enters the first cooling section 3 of the platinum channel for free cooling, and is cooled to 1510-1520°C at a cooling rate of 10-20°C / h, and the cooling time is 3-5h.

[0024] Example 1

[0025] The method of this embodiment for preventing the liquid level of the platinum channel from diving during the production of liquid crystal glass comprises the following steps:

[0026] The initial temperature of the S1 glass liquid is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is kept warm. The temperature of the glass liquid when it reaches the outlet of the platinum channel lifting section 1 is 1510°C, and the time taken is 3 hours;

[0027] After the S2 glass liquid enters the horizontal section 2 of the platinum channel, the glass liquid is heated to 1600°C at a heating rate of 25°C / h, which takes 4 hours;

[0028] The S3 glass liquid enters the first cooling section 3 of the platinum channel and is cooled to 1505°C at a cooling rate of 20°C / h, which takes 5 hours.

[0029] Example 2

[0030] The method of this embodiment for preventing the liquid level of the platinum channel from diving during the production of liquid crystal glass comprises the following steps:

[0031] The initial glass liquid temperature of S1 is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is kept warm. The temperature of the glass liquid when it reaches the outlet of the platinum channel lifting section 1 is 1505°C, and the time taken is 2 hours;

[0032] After the S2 glass liquid enters the horizontal section 2 of the platinum channel, the glass liquid is heated to 1600°C at a heating rate of 25°C / h, which takes 4 hours;

[0033] The S3 glass liquid enters the first cooling section 3 of the platinum channel and is cooled to 1505°C at a cooling rate of 20°C / h, which takes 5 hours.

[0034] Example 3

[0035] The method of this embodiment for preventing the liquid level of the platinum channel from diving during the production of liquid crystal glass comprises the following steps:

[0036] The initial temperature of the S1 glass liquid is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is kept warm. The temperature of the glass liquid when it reaches the outlet of the platinum channel lifting section 1 is 1500°C, and the time taken is 3 hours;

[0037] After the S2 glass liquid enters the horizontal section 2 of the platinum channel, the glass liquid is heated to 1600°C at a heating rate of 25°C / h, which takes 4 hours;

[0038] The S3 glass liquid enters the first cooling section 3 of the platinum channel and is cooled to 1505°C at a cooling rate of 20°C / h, which takes 5 hours.

[0039] Example 4

[0040] The method of this embodiment for preventing the liquid level of the platinum channel from diving during the production of liquid crystal glass comprises the following steps:

[0041] The initial glass liquid temperature of S1 is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is kept warm. The temperature of the glass liquid when it reaches the outlet of the platinum channel lifting section 1 is 1505°C, and the time taken is 3 hours;

[0042] After the S2 glass liquid enters the horizontal section 2 of the platinum channel, the glass liquid is heated to 1605°C at a heating rate of 25°C / h, and the time taken is 4 hours;

[0043] The S3 glass liquid enters the first cooling section 3 of the platinum channel and is cooled to 1505°C at a cooling rate of 20°C / h, which takes 5 hours.

[0044] Example 5

[0045] The method of this embodiment for preventing the liquid level of the platinum channel from diving during the production of liquid crystal glass comprises the following steps:

[0046] The initial glass liquid temperature of S1 is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is kept warm. The temperature of the glass liquid when it reaches the outlet of the platinum channel lifting section 1 is 1505°C, and the time taken is 3 hours;

[0047] After the S2 glass liquid enters the horizontal section 2 of the platinum channel, the glass liquid is heated to 1610°C at a heating rate of 25°C / h, and the time taken is 4 hours;

[0048] The S3 glass liquid enters the first cooling section 3 of the platinum channel and is cooled to 1505°C at a cooling rate of 20°C / h, which takes 5 hours.

[0049] Example 6

[0050] The method of this embodiment for preventing the liquid level of the platinum channel from diving during the production of liquid crystal glass comprises the following steps:

[0051] The initial glass liquid temperature of S1 is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is kept warm. The temperature of the glass liquid when it reaches the outlet of the platinum channel lifting section 1 is 1505°C, and the time taken is 3 hours;

[0052] After the S2 glass liquid enters the horizontal section 2 of the platinum channel, the glass liquid is heated to 1605°C at a heating rate of 25°C / h, and the time taken is 4 hours;

[0053] The S3 glass liquid enters the first cooling section 3 of the platinum channel and is cooled to 1500°C at a cooling rate of 20°C / h, which takes 5 hours.

[0054] Example 7

[0055] The method of this embodiment for preventing the liquid level of the platinum channel from diving during the production of liquid crystal glass comprises the following steps:

[0056] The initial glass liquid temperature of S1 is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is kept warm. The temperature of the glass liquid when it reaches the outlet of the platinum channel lifting section 1 is 1505°C, and the time taken is 3 hours;

[0057] After the S2 glass liquid enters the horizontal section 2 of the platinum channel, the glass liquid is heated to 1605°C at a heating rate of 25°C / h, and the time taken is 4 hours;

[0058] The S3 glass liquid enters the first cooling section 3 of the platinum channel and is cooled to 1510°C at a cooling rate of 20°C / h, which takes 5 hours.

[0059] Comparative Example 1

[0060] The difference between Comparative Example 1 and Example 4 is that the initial glass liquid temperature of S1 is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is heated at a heating rate of 25°C / h to a glass liquid temperature of 1560°C at the outlet of the platinum channel lifting section 1, and the heating time is 3 hours.

[0061] Comparative Example 2

[0062] The difference between Comparative Example 2 and Example 4 is that the initial glass liquid temperature of S1 is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is heated at a heating rate of 25°C / h to a glass liquid temperature of 1530°C at the outlet of the platinum channel lifting section 1, and the heating time is 3 hours.

[0063] Comparative Example 3

[0064] The difference between Comparative Example 3 and Example 4 is that the initial glass liquid temperature of S1 is 1505°C. After entering the platinum channel lifting section 1, the glass liquid is heated at a heating rate of 25°C / h to a glass liquid temperature of 1515°C at the outlet of the platinum channel lifting section 1, and the heating time is 3 hours.

[0065] Comparative Example 4

[0066] The difference between Comparative Example 4 and Example 4 is that after the S2 glass liquid enters the horizontal section 2 of the platinum channel, the glass liquid is heated to 1590° C. at a heating rate of 25° C. / h, and the time taken is 4 hours.

[0067] Comparative Example 5

[0068] The difference between Comparative Example 5 and Example 4 is that the S3 glass liquid enters the first cooling section 3 of the platinum channel, and is cooled to 1540° C. at a cooling rate of 20° C. / h, and the time taken is 5 hours.

[0069] The glass liquid temperature, liquid level diving times, single liquid level diving recovery time and product yield at each section of the platinum channel in Examples 1-7 and Comparative Examples 1-5 are shown in Table 1-2. The number of bubble defects in the product is detected by a bubble detector to obtain the total bubble volume of the product per hour; the bubble defect rate refers to the percentage of defective products caused by bubble defects in the total number of products produced.

[0070] Table 1 Glass liquid temperature, number of liquid level dives, single liquid level dive recovery time and product yield

[0071]

[0072] Table 2 Glass liquid temperature, number of liquid level dives, single liquid level dive recovery time and product yield

[0073]

[0074] It can be seen from Example 4 and Comparative Examples 1-3 in Comparative Table 1-2 that the glass liquid is kept warm after entering the platinum channel lifting section 1 so that the temperature difference between the glass liquid at the outlet and the inlet of the platinum channel lifting section 1 is less than 5°C, so that the gas solubility of the glass liquid entering the platinum channel lifting section 1 does not change, and the gas is prevented from precipitating out after the gas solubility of the glass liquid decreases, and then aggregating into bubbles, and aggregating into large bubbles on the upper edge of the horizontal part at the outlet end of the platinum channel lifting section 1, thereby causing a sudden change in the detected liquid level, stabilizing the feeding state and the liquid level, eliminating the liquid level diving phenomenon, and reducing the bubble defect rate of the product.

[0075] By comparing Example 4 and Comparative Example 4, it can be seen that by raising the temperature of the molten glass in the horizontal section 2 of the platinum channel to within the range defined by the present invention, the gas solubility of the molten glass in the horizontal section 2 of the platinum channel can be rapidly reduced, which is beneficial to the precipitation of the gas and causes the gas to gather into bubbles and escape, thereby lowering the gas rate of the molten glass and reducing the bubble defect rate of the product.

[0076] By comparing Example 4 and Comparative Example 5, it can be seen that by lowering the temperature of the molten glass in the first cooling section 3 of the platinum channel to within the range defined by the present invention, the gas solubility of the molten glass in the first cooling section 3 of the platinum channel can be rapidly increased, small bubbles can be absorbed, and thus visible bubbles can be eliminated, thereby reducing the bubble defect rate of the product.

Claims

1. A method for preventing liquid level diving in a platinum channel during production of liquid crystal glass, characterized in that: The following steps are involved: After the S1 glass liquid enters the platinum channel lifting section (1), the glass liquid is kept warm; After the S2 glass liquid enters the horizontal section (2) of the platinum channel, the glass liquid is heated to 1600-1610°C; The S3 glass liquid enters the first cooling section (3) of the platinum channel for cooling, and the first cooling section is provided with a liquid level meter (4).

2. The method for preventing the liquid level of the platinum channel from diving in the production of liquid crystal glass according to claim 1, characterized in that: In step S1, the temperature of the glass liquid at the inlet of the platinum channel lifting section (1) is lower than the temperature of the glass liquid at the outlet of the platinum channel lifting section (1), and the temperature difference is less than 5°C.

3. The method for preventing the liquid level of the platinum channel from diving in the production of liquid crystal glass according to claim 1, characterized in that: In step S1, the insulation time is 2-3 hours.

4. The method for preventing the liquid level of the platinum channel from diving in the production of liquid crystal glass according to claim 1, characterized in that: In step S1, the temperature of the glass liquid at the entrance of the platinum channel lifting section (1) is 1500-1510°C.

5. The method for preventing the liquid level of the platinum channel from diving in the production of liquid crystal glass according to claim 1, characterized in that: In step S2, the heating rate is 20-30°C / h and the heating time is 3-5h.

6. The method for preventing the liquid level of the platinum channel from diving in the production of liquid crystal glass according to claim 1, characterized in that: In step S3, the glass liquid is cooled to 1500-1510°C.

7. The method for preventing the liquid level of the platinum channel from diving in the production of liquid crystal glass according to claim 6, characterized in that: In step S3, the cooling rate is 10-20°C / h and the cooling time is 3-5h.

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