US-20260126327-A1 - APPARATUSES AND METHODS FOR IMPROVING RELIABILITY OF THERMOCOUPLES IN COOLING SECTIONS OF CHANNELS DURING HEATING STAGES

US20260126327A1US 20260126327 A1US20260126327 A1US 20260126327A1US-20260126327-A1

Abstract

Provided is an apparatus for improving reliability of a thermocouple in a cooling section of a channel during a heating stage. The apparatus includes a thermocouple and at least one thermocouple sheet installed on a cooling tube body. Each of the at least one thermocouple sheet is provided with a notch, and the notch has a groove structure. A cavity is formed between the notch and the cooling tube body, and a root of the thermocouple is disposed in the cavity. The root of the thermocouple is a temperature measuring point of a welded thermocouple.

Inventors

Menglong WANG
Hongrong HOU
Wei Yang
Chao Yu
Ting Luo

Assignees

CAIHONG DISPLAY DEVICES CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251230
Priority Date: 20240929

Claims (12)

1 . An apparatus for improving reliability of a thermocouple in a cooling section of a channel during a heating stage, comprising: a thermocouple; and at least one thermocouple sheet installed on a cooling tube body, wherein each of the at least one thermocouple sheet is provided with a notch, the notch having a groove structure; a cavity is formed between the notch and the cooling tube body; and a root of the thermocouple is disposed in the cavity, wherein the root of the thermocouple is a temperature measuring point of a welded thermocouple.
2 . The apparatus of claim 1 , wherein a ceramic fiber cloth is provided over the thermocouple sheet.
3 . The apparatus of claim 2 , wherein a surface area of the ceramic fiber cloth is greater than a surface area of the thermocouple sheet.
4 . The apparatus of claim 2 , wherein a filling material is provided over the ceramic fiber cloth.
5 . The apparatus of claim 1 , wherein the notch is a rectangular slit, wherein a slit width of the notch is greater than 1.2 to 1.5 times a diameter of the thermocouple, and the slit width is less than a diameter of the temperature measuring point.
6 . The apparatus of claim 1 , wherein a length of the notch is within a range of 20 mm to 50 mm.
7 . The apparatus of claim 1 , wherein the at least one thermocouple sheet includes a plurality of thermocouple sheets, and each of the plurality of thermocouple sheets is provided with the notch.
8 . The apparatus of claim 1 , wherein the at least one thermocouple sheet is provided with a plurality of notches.
9 . The apparatus of claim 1 , wherein the at least one thermocouple sheet is welded to the cooling tube body.
10 - 13 . (canceled)
14 . A method for improving reliability of a thermocouple in a cooling section of a channel during a heating stage, adopting the apparatus according to claim 1 , comprising: installing the at least one thermocouple sheet on the cooling tube body; and placing the thermocouple at the notch of the at least one thermocouple sheet, wherein when the thermocouple is subjected to expansion or sagging of the cooling section, the notch having the groove structure allows the thermocouple to release a displacement amount thereby improving the reliability of the thermocouple.
15 . (canceled)

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of International Application No. PCT/CN2025/115611, filed on Aug. 19, 2025, which claims priority to Chinese Patent Application No. 202411374788.2, filed on Sep. 29, 2024, the entire contents of each of which are hereby incorporated by reference. TECHNICAL FIELD The present disclosure relates to a technical field of substrate glass manufacturing, and in particular to apparatus and methods for improving reliability of thermocouples in cooling sections of channels during heating stages. BACKGROUND The hot end technology of substrate glass is a core portion of the preparation of the substrate glass. Each functional zone section of a hot end equipment has its own different process settings. The internal temperature of most regions of the main body of the hot end equipment typically exceeds 1400° C., requiring stable long-term operation. A thermocouple serves as an essential basic component of the hot end equipment for temperature monitoring and process control. Different numbers and positions of thermocouples are generally designed according to different structures and materials of the functional zone sections, respectively. In general, in a high-temperature zone (i.e., a process interval in which the temperature exceeds 1600° C.), the primary issue affecting the thermocouples is material oxidation and volatilization during the long-term operation. By contrast, a low-temperature zone operates relatively constantly, and most thermocouples in the low-temperature zone can meet a service life requirement of more than four years. A certain number of thermocouples are disposed at a top portion of a cooling section within the low-temperature zone. The thermocouples are primarily configured to monitor a flow rate and a temperature of molten glass ultimately delivered to a forming zone. However, the thermocouples exhibit a high incidence of failure during a heating stage. Statistical analysis of multiple production lines has revealed the basic pattern of thermocouple failure in the low-temperature zone. The thermocouple failure predominantly occurs during a later phase of the heating stage, with temperatures generally concentrated between 900° C. and 1200° C. Furthermore, compared to other portions, the thermocouple failure exhibits a distinctly clustered distribution. Mechanism analysis has substantially confirmed that the failure of the thermocouples disposed at the top portion of the cooling section relates to collapse deformation and axial expansion displacement of a cooling tube body during a high-temperature empty-tube stage. In the absence of the molten glass within the tube body, the tube material gradually softens under the high temperature, resulting in slow creep collapse. Combined with the simultaneous axial expansion, pronounced local displacement occurs. In addition, the thermocouples located at the top portion are sintered to a filling layer and thus cannot move freely, causing local stress to accumulate and ultimately reach a tensile limit of thermocouple wires of the thermocouples. Accordingly, for the thermocouples located at the top portion of the cooling tube, at the current stage where it is difficult to significantly enhance the strength of the thermocouple wires themselves, the primary solution to the problem lies in maintaining sufficient mobility of the thermocouple wires, so that the thermocouple wires release the tensile stress over a certain distance. SUMMARY One or more embodiments of the present disclosure provide an apparatus for improving reliability of a thermocouple in a cooling section of a channel during a heating stage. The apparatus includes a thermocouple and at least one thermocouple sheet installed on a cooling tube body. Each of the at least one thermocouple sheet is provided with a notch, and the notch has a groove structure. A cavity is formed between the notch and the cooling tube body. A root of the thermocouple is disposed in the cavity, and the root of the thermocouple is a temperature measuring point of a welded thermocouple. In some embodiments, a ceramic fiber cloth is provided over the thermocouple sheet. In some embodiments, a surface area of the ceramic fiber cloth is greater than a surface area of the thermocouple sheet. In some embodiments, a filling material is provided over the ceramic fiber cloth. In some embodiments, the notch is a rectangular slit, a slit width of the notch is greater than 1.2 to 1.5 times a diameter of the thermocouple, and the slit width is less than a diameter of the temperature measuring point. In some embodiments, a length of the notch is within a range of 20 mm to 50 mm. In some embodiments, the at least one thermocouple sheet includes a plurality of thermocouple sheets, and each of the plurality of thermocouple sheets is provided with the notch. In some embodiments, the at least one thermocouple sheet is provided with a plurality of notches. In some embod