Device for preventing high-temperature volatilization of bottom thermocouple of substrate glass furnace

Abstract

Provided in the present invention is a device for preventing high-temperature volatilization of a bottom thermocouple of a substrate glass furnace. The device comprises a waterproof junction box, a metal connecting pipe, a precious-metal protective casing, a thermocouple core and a corundum protection pipe, wherein an insulating material is provided between the metal connecting pipe and the precious-metal protective casing, a high-purity alumina slurry is filled between the precious-metal protective casing and the thermocouple core in a sealing manner, and the insulating material is made of high-purity alumina. In the present application, by respectively arranging the insulating material and the high-purity alumina slurry at two ends of the thermocouple core, high-temperature oxygen can be prevented from entering and causing oxidation and volatilization of a wire diameter and the casing, which oxidation and volatilization would otherwise affect the measurement precision of a thermocouple wire; and the furnace can efficiently and stably operate for a long time during a five-year operation cycle, and a direction and basis are provided for the optimization and adjustment of the process.

Description

A device for preventing high-temperature volatilization of thermocouples at the bottom of a glass furnace Technical Field

[0001] The present invention belongs to the technical field of temperature measurement of thermocouples at the bottom of a high-generation substrate glass furnace, and particularly relates to a device for preventing high-temperature volatilization of thermocouples at the bottom of a substrate glass furnace. Background Art

[0002] Glass products have always been widely used in the display field. Without the support of the glass industry, the development of the display device industry is unimaginable. Although other materials can replace glass materials in some applications, they still cannot replace the excellent performance of glass. From the traditional color picture tube industry to the current flat panel display industry, glass has always played a key role in display devices as a key component. In fact, it is the frame and carrier of the entire device, and also an optical element. As the upper and lower substrates of flat panel display devices, both require fine microscopic semiconductor process processing. To meet the requirements of large feed volume, high temperature erosion and long-term efficient and stable operation of substrate glass kilns, the temperature measurement accuracy and long-term stability of the thermocouples at the bottom of the kiln will become one of the difficult problems that must be solved.

[0003] During the manufacturing process of substrate glass, the glass batch material must first be stably and smoothly fed into the feeding port of the melting furnace through the feeding system, and then melted, clarified and homogenized in the furnace to provide qualified homogeneous glass liquid for the next process. The glass liquid melted in the melting furnace is alkali-free high-aluminum borosilicate glass. This glass product is mainly substrate glass for flat panel displays.

[0004] The kiln bottom thermocouple is the primary means of measuring the glass liquid temperature throughout the kiln's entire life cycle, providing a powerful direction for process adjustment and monitoring. Once the measurement accuracy of the bottom thermocouple is significantly reduced or fails, it will bring a fatal blind spot to the process adjustment and optimization of the production line. Therefore, only by solving the problem of high-temperature oxidation and volatilization of the bottom thermocouple can the long-term, efficient and stable operation of the bottom thermocouple be achieved within the five-year operation cycle of the kiln, providing direction and basis for process optimization and adjustment.

[0005] Summary of the Invention

[0006] The present invention is achieved through the following technical solutions:

[0007] A device for preventing high-temperature volatilization of thermocouples at the bottom of a substrate glass kiln, comprising a waterproof junction box, a metal connecting pipe, a precious metal protective sleeve, a thermocouple core and a corundum protective tube, wherein an insulating material is provided between the metal connecting pipe and the precious metal protective sleeve, and a gap sealing material formed by high-purity alumina slurry is sealed and filled between the precious metal protective sleeve and the thermocouple core, wherein the insulating material is high-purity alumina; the corundum protective tube is partially sleeved in the metal connecting pipe, and the other part is sleeved in the precious metal protective sleeve.

[0008] Furthermore, the purity of the high-purity aluminum oxide used in the insulating material is greater than or equal to 99%.

[0009] Furthermore, the insulation resistance of the insulating material at room temperature is greater than 1014Ω.

[0010] Furthermore, the precious metal protection sleeve is made of PtRh10.

[0011] Furthermore, the diameter of the precious metal protection sleeve is 12 mm.

[0012] Furthermore, the thermocouple core adopts a B-type thermocouple or an R-type thermocouple, wherein the positive electrode of the B-type thermocouple is PtRh30 and the negative electrode is PtRh6, the positive electrode of the R-type thermocouple is PtRh13 and the negative electrode is Pt, and the wire diameter of the thermocouple core is 0.8 mm.

[0013] Furthermore, the high-purity alumina slurry includes high-purity alumina and a rheological agent.

[0014] Furthermore, the purity of the high-purity alumina in the high-purity alumina slurry is greater than or equal to 99%.

[0015] Furthermore, the rheological agent in the high-purity alumina slurry is carboxymethyl cellulose.

[0016] Furthermore, the addition amount of the rheological agent is 1.0% to 1.2%, and the sedimentation volume of the suspension in the high-purity alumina slurry is 9-11%. Beneficial effects

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

[0018] The present invention provides a device for preventing high-temperature volatilization of a thermocouple at the bottom of a substrate glass kiln, comprising a waterproof junction box, a metal connecting tube, a precious metal protective sleeve, a thermocouple core and a corundum protective tube, wherein an insulating material is arranged between the metal connecting tube and the precious metal protective sleeve, and a high-purity alumina slurry is sealed and filled between the precious metal protective sleeve and the thermocouple core, wherein the insulating material is high-purity alumina; a portion of the corundum protective tube is sleeved in the metal connecting tube, and the other portion is sleeved in the precious metal protective sleeve; by respectively arranging insulating material and high-purity alumina slurry at both ends of the thermocouple core, the present application can prevent high-temperature oxygen from entering and causing oxidation volatilization of the wire diameter and the sleeve, thereby affecting the measurement accuracy of the thermocouple wire; and can enable the kiln to continue to operate efficiently and stably for a long time within a five-year operation cycle, providing direction and basis for process optimization and adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic structural diagram of a device for preventing high-temperature volatilization of a thermocouple at the bottom of a glass furnace according to a specific embodiment of the present invention;

[0020] FIG2 is a partial diagram of a connecting tube and a precious metal protection sleeve in a specific embodiment of the present invention.

[0021] In the figure: 1. Waterproof junction box; 2. Metal connecting pipe; 3. Precious metal protective sleeve; 4. Gap sealing material; 5. Thermocouple core; 6. Insulation material; 7. Corundum protective tube. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0023] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described 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 should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention 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 numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof 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 clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0025] The present invention provides a device for preventing high-temperature volatilization of thermocouples at the bottom of a substrate glass kiln, as shown in Figures 1 and 2, comprising a waterproof junction box 1, a metal connecting pipe 2, a precious metal protective sleeve 3, a thermocouple core 5 and a corundum protective tube 7. An insulating material 6 is provided between the metal connecting pipe 2 and the precious metal protective sleeve 3. A gap sealing material 4 formed by high-purity alumina slurry is sealed and filled between the precious metal protective sleeve 3 and the thermocouple core 5. The insulating material 6 is made of high-purity alumina; part of the corundum protective tube 7 is sleeved in the metal connecting pipe 2, and the other part is sleeved in the precious metal protective sleeve 3.

[0026] Specifically, the waterproof junction box 1 described in this embodiment is used to protect the internal wires from the intrusion of moisture, thereby avoiding the occurrence of electrical accidents such as short circuits and leakages.

[0027] It should be noted that the corundum protection tube 6 is a tubular structure made of corundum material, which has excellent high temperature resistance, corrosion resistance and wear resistance. It is commonly used in various high-temperature furnaces, thermocouple protection tubes, heat exchangers and other fields. In this embodiment, the corundum protection tube 6 is used as a protective tube for the thermocouple core 5 in the high-temperature furnace to prevent the thermocouple core 5 from corrosion and wear at high temperatures. Due to its excellent high temperature resistance, the corundum protection tube 6 can be used for a long time at high temperatures of up to 1800°C. In addition, it also has good corrosion resistance and can resist the erosion of various chemical substances.

[0028] Preferably, the purity of the high-purity alumina used in the insulating material 6 is greater than or equal to 99%. It should be noted that the high-purity alumina does not contain other impurities and preferably has a purity of 99.5%. Furthermore, the insulation resistance of the insulating material 6 at room temperature is greater than 1014Ω.

[0029] Preferably, the precious metal protection sleeve 3 is made of PtRh10; further, the diameter of the precious metal protection sleeve 3 is 12 mm; it should be noted that the precious metal protection sleeve 3 is usually a tube made of precious metals such as platinum, gold, silver, palladium, etc., which has the characteristics of high purity, high density and high corrosion resistance. These metals have very good chemical stability and can be used in a variety of corrosive environments; in this embodiment, the precious metal protection sleeve 3 is used to protect the thermocouple core 5.

[0030] Preferably, the thermocouple core 5 adopts a B-type thermocouple or an R-type thermocouple, wherein the positive electrode of the B-type thermocouple is PtRh30 and the negative electrode is PtRh6, and the positive electrode of the R-type thermocouple is PtRh13 and the negative electrode is Pt, and the wire diameter of the thermocouple core 5 is 0.8 mm.

[0031] It should be noted that the B-type thermocouple, also known as B-type thermocouple wire, uses 70% platinum and 30% rhodium as the conductor material. This thermocouple has excellent performance in a very high temperature measurement range, approximately 800 degrees Celsius to 1800 degrees Celsius. The B-type thermocouple has good physical and chemical properties, thermoelectric potential stability and good oxidation resistance at high temperatures, and is suitable for use in oxidizing and inert atmospheres.

[0032] The R-type thermocouple, also known as a single platinum-rhodium thermocouple, has one conductor composed of 87% platinum and 13% rhodium, while the other conductor is 100% pure platinum. This thermocouple is suitable for temperatures up to 1600 degrees Celsius and offers the highest accuracy, best stability, a wide temperature measurement range, and a long service life. The R-type thermocouple has excellent physical and chemical properties, thermoelectric potential stability, and good oxidation resistance at high temperatures, making it suitable for use in oxidizing and inert atmospheres. However, it has low thermoelectric potential and thermoelectric potential ratio, low sensitivity, decreased mechanical strength at high temperatures, and is very sensitive to pollution. Furthermore, the precious metal material is expensive, resulting in a large one-time investment.

[0033] Those skilled in the art can select an appropriate B-type thermocouple or R-type thermocouple according to actual production needs.

[0034] Preferably, the high-purity alumina slurry comprises high-purity alumina and a rheological agent; further, the purity of the high-purity alumina in the high-purity alumina slurry is greater than or equal to 99%; further, the rheological agent in the high-purity alumina slurry is carboxymethyl cellulose; further, the addition amount of the rheological agent is 1.0% to 1.2%, and the sedimentation volume of the suspension in the high-purity alumina slurry is 9-11%.

[0035] It should be noted that rheological agents are additives used in coating technology to provide pseudoplastic or thixotropic properties. Rheological properties are determined by the composition and concentration of the ingredients in the coating formula. The concentration of the rheological agent determines the coating's rheological properties, affecting the coating's viscosity, thixotropy, flowability, and other properties. Increasing the rheological agent concentration typically increases the coating's viscosity, decreases its flowability, and enhances its thixotropy. Thixotropy refers to the change in viscosity of a coating when subjected to shear forces, which affects its flow and deformation properties. Therefore, the concentration of the rheological agent can be used to control the coating's leveling, anti-sagging, edge coverage, and other properties. Furthermore, the concentration of the rheological agent can affect the coating's drying rate and film-forming process. Excessively high or low concentrations can affect the coating's drying rate and film-forming process, thereby affecting the coating's performance and quality.

[0036] Through a large number of experiments, under the premise of ensuring the fluidity, molding speed and later structural strength of the high-purity alumina slurry, the addition amount of the rheological agent was obtained to be 1.0% to 1.2%. At this time, the sedimentation volume of the suspension in the high-purity alumina slurry is 9-11%, and the high-purity alumina slurry has good physical properties.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for preventing high-temperature volatilization of thermocouples at the bottom of a substrate glass furnace, characterized in that: The invention comprises a waterproof junction box (1), a metal connecting tube (2), a precious metal protective sleeve (3), a thermocouple core (5) and a corundum protective tube (7); an insulating material (6) is arranged between the metal connecting tube (2) and the precious metal protective sleeve (3); a gap sealing material (4) formed by high-purity alumina slurry is sealed and filled between the precious metal protective sleeve (3) and the thermocouple core (5); the insulating material (6) is made of high-purity alumina; a part of the corundum protective tube (7) is sleeved in the metal connecting tube (2), and another part is sleeved in the precious metal protective sleeve (3).

2. A device for preventing high-temperature volatilization of thermocouples at the bottom of a glass substrate furnace according to claim 1, characterized in that: The purity of the high-purity aluminum oxide used in the insulating material (6) is greater than or equal to 99%.

3. The device for preventing high-temperature volatilization of thermocouples at the bottom of a glass furnace according to claim 1, characterized in that: The insulation material (6) has an insulation resistance greater than 1014Ω at room temperature.

4. The device for preventing high-temperature volatilization of thermocouples at the bottom of a glass furnace according to claim 1, characterized in that: The noble metal protection sleeve (3) is made of PtRh10.

5. The device for preventing high-temperature volatilization of thermocouples at the bottom of a glass furnace according to claim 1, characterized in that: The diameter of the noble metal protection sleeve (3) is 12 mm.

6. The device for preventing high-temperature volatilization of thermocouples at the bottom of a glass furnace according to claim 1, characterized in that: The thermocouple core (5) adopts a B-type thermocouple or an R-type thermocouple, wherein the positive electrode of the B-type thermocouple is PtRh30 and the negative electrode is PtRh6, and the positive electrode of the R-type thermocouple is PtRh13 and the negative electrode is Pt. The wire diameter of the thermocouple core (5) is 0.8 mm.

7. The device for preventing high-temperature volatilization of thermocouples at the bottom of a glass furnace according to claim 1, characterized in that: The high-purity alumina slurry comprises high-purity alumina and a rheological agent.

8. A device for preventing high-temperature volatilization of thermocouples at the bottom of a glass substrate furnace according to claim 7, characterized in that: The purity of the high-purity alumina in the high-purity alumina slurry is greater than or equal to 99%.

9. The device for preventing high-temperature volatilization of thermocouples at the bottom of a glass substrate furnace according to claim 7, characterized in that: The rheological agent in the high-purity alumina slurry is carboxymethyl cellulose.

10. The device for preventing high-temperature volatilization of thermocouples at the bottom of a glass substrate furnace according to claim 7, characterized in that: The addition amount of the rheological agent is 1.0% to 1.2%, and the sedimentation volume of the suspension in the high-purity alumina slurry is 9-11%.

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