High-temperature creep quantity analysis method of overflow brick and related process control method

Abstract

The invention discloses a high-temperature creep quantity analysis method of an overflow brick and a related process control method, and belongs to the technical field of glass substrate manufacturing. According to the method, through the creep test of the system, the function relationship among the steady-state creep rate of the overflow brick material, the bending stress and the temperature is established, so that the prediction of the creep quantity of the overflow brick in a high-temperature working environment is more accurate; through structural simulation and theoretical analysis, the geometric dimension, material characteristics and working environment temperature factors of the overflow brick are comprehensively considered, and a scientific basis is provided for designing the high-strength and low-creep overflow brick; a standardized high-temperature creep analysis process is established, so that evaluation and control of the creep quantity of the overflow brick are more systematized and normalized, the quality of a formed glass substrate is further improved, production interruption and loss caused by the creep problem are reduced, and the production efficiency is improved. On the basis of a creep analysis result, the production process is optimized through reasonable pressure control of the clamping air cylinder, and the quality of the formed glass substrate is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of glass substrate manufacturing, and in particular to a high-temperature creep analysis method of an overflow brick and a related process control method. Background Art

[0002] At high temperatures, the viscosity of the liquid phase inside the material decreases and the amount increases, making it easier for the material to undergo plastic deformation, i.e. creep, when subjected to external forces. As the temperature rises, the creep rate of the material usually increases significantly. The increase in creep rate will cause the material to reach its limit state in a shorter period of time, resulting in fracture or failure. Therefore, there is a close relationship between high temperature and creep performance. High temperature will intensify the creep behavior of the material and shorten its creep life, while creep performance directly affects the application effect and safety of the material in a high temperature environment.

[0003] The glass substrate used in the manufacturing field of TFT-LCD (thin film transistor display) flat panel displays is manufactured in a high temperature environment by overflow pull-down method. In the molding process, the glass liquid melted by the glass melting furnace is supplied to the molten overflow pull-down molding device for manufacturing. The overflow brick is one of the core components of the glass substrate manufacturing molding device. In the process of manufacturing glass substrates, the overflow brick needs to go through the heating, wetting and plate guiding stages. The average temperature of its working environment is about 1207℃. Under high temperature conditions, the overflow brick creeps and sinks. The creep process can be divided into three stages: initial deceleration creep, steady-state creep and accelerated creep. Each stage corresponds to a different strain growth creep rate and damage risk. In the initial deceleration creep stage, the time is short, and the strain increases with time, but the rate of increase gradually slows down; in the steady-state creep stage, the strain increases at a uniform rate with time, and the creep rate is the smallest, but the time is long; in the accelerated creep stage, the creep rate increases rapidly, and the strain increases with time and accelerates until it reaches the rupture point. The greater the stress, the shorter the total creep time; the smaller the stress, the longer the total creep time.

[0004] The creep and sinking of overflow bricks will cause uneven distribution of the flow of molten glass in the width direction of the glass plate, which will lead to thinning of the far and near ends of the formed glass substrate and thickening of the middle part, resulting in poor quality. Especially for large-sized overflow bricks, due to their large size and heavy weight, the high-temperature creep rate is faster, which has an adverse effect on the stability of the production process.

[0005] Reasonable clamping cylinder pressure can effectively control the creep amount. Therefore, in order to cope with the adverse effects of overflow brick creep, how to accurately analyze the high-temperature creep performance of overflow bricks and provide reference process suggestions for clamping cylinder pressure during the overflow brick heating, wetting and plate leading stages for the production line is a very important task, which has far-reaching practical significance for the manufacturing and production of glass substrates. Summary of the invention

[0006] The purpose of the present invention is to provide a method for analyzing the high-temperature creep of overflow bricks and a related process control method. Based on the research on high-strength and low-creep overflow bricks, a standardized high-temperature creep analysis method is established to provide the production line with reference process suggestions for the clamping cylinder pressure in the heating, wetting and plate-leading stages of overflow bricks, so as to overcome the problem in the prior art that the quality of the formed glass substrate does not meet the standards due to high-temperature creep of overflow bricks.

[0007] The present invention solves the above technical problems through the following technical solutions:

[0008] A method for analyzing the high temperature creep of overflow bricks comprises the following steps:

[0009] S1. Select the overflow brick used for mature glass substrate manufacturing as the reference overflow brick. Through simulation, establish the first functional relationship between the deformation bending amount Y and the clamping cylinder pressure P of the reference overflow brick under normal temperature steady-state conditions, and obtain the maximum cylinder pressure P of the reference overflow brick under normal temperature steady-state conditions. maxref and the maximum bending amount Y maxref ;

[0010] S2. Construct a designed overflow brick that is equivalent to the reference overflow brick, obtain the structural parameters of the designed overflow brick and the reference overflow brick, and calculate the bending stress ratio K of the designed overflow brick and the reference overflow brick and the maximum bending stress σ of the designed overflow brick based on the structural parameters. max ; Based on the first functional relationship, combined with the bending stress ratio K and the maximum bending stress σ max , Maximum cylinder pressure P maxref and the maximum bending amount Y maxref , calculate and design the overflow brick bending stress σ corresponding to the clamping cylinder pressure P 2 ;

[0011] S3. Conduct creep tests based on overflow brick materials and establish steady-state creep rate based on test data The second functional relationship between bending stress σ and temperature T; obtain the working environment temperature T of the designed overflow brick W Based on the second functional relationship, the overflow brick bending stress σ corresponding to the clamping cylinder pressure P is designed. 2 ; Get the steady-state creep rate of the designed overflow brick

[0012] S4. Steady-state creep rate based on designed overflow bricks Calculate the creep amount Δ of the designed overflow brick.

[0013] Furthermore, the first functional relationship is specifically:

[0014] .

[0016] Furthermore, the structural parameters include a first structural parameter and a second structural parameter, the first structural parameter includes: overflow groove width, overflow groove wall thickness, overflow groove depth, inlet section first height, inlet section second height, distal crotch height, overflow surface width and material density, and the second structural parameter includes: proximal crotch height and overflow inclination angle;

[0017] Calculate the bending stress ratio K of the designed overflow brick and the reference overflow brick and the maximum bending stress σ of the designed overflow brick max The specific steps include:

[0018] Calculating the equivalent height correction coefficient of the designed overflow brick and the reference overflow brick according to the first structural parameter;

[0019] Calculating the equivalent thickness of the designed overflow brick and the reference overflow brick according to the first structural parameter and the second structural parameter;

[0020] According to the first structural parameter, in combination with the calculated equivalent height correction coefficient and equivalent thickness, the equivalent height of the designed overflow brick and the reference overflow brick is calculated;

[0021] According to the overflow surface width and equivalent height of the designed overflow brick and the reference overflow brick, the bending stress ratio K of the designed overflow brick and the reference overflow brick is calculated; according to the overflow surface width and equivalent height of the designed overflow brick, the maximum bending stress σ of the designed overflow brick is calculated max ;

[0022] Calculate and design the overflow brick bending stress σ corresponding to the clamping cylinder pressure P 2 The specific steps include:

[0023] Obtain the weight of the designed overflow brick and the reference overflow brick plus glass and the clamping cylinder action area, combined with the maximum cylinder pressure P maxref , calculate the maximum cylinder pressure P of the overflow brick under normal temperature steady state conditions max Based on the overflow surface width of the designed overflow brick and the reference overflow brick, combined with the bending stress ratio K and the maximum bending amount Y of the reference overflow brick under normal temperature steady state conditions maxref , calculate the maximum bending value Y of the overflow brick under normal temperature steady state conditions max ;

[0024] Based on the equivalent relationship between the designed overflow brick and the reference overflow brick, the maximum bending amount Y max and the maximum cylinder pressure P max Substituting into the first functional relationship, we get formula (2). Based on the principle that the ratio of the designed overflow brick bending stress to the maximum bending stress and the ratio of the deformation bending amount to the maximum deformation bending amount are equal, we get formula (3). Combining formulas (2) and (3) we get the overflow brick bending stress σ of the designed overflow brick corresponding to the clamping cylinder pressure P: 2 .

[0025] Furthermore, the specific formula for calculating the equivalent height correction coefficient of the designed overflow brick and the reference overflow brick is:

[0026] K d =-8.59468×10 -6 ×(w+2B)×(h+h 1 +h 2 +H O )×W×ρ+1.169457

[0027] K dref =-8.59468×10 -6 ×(w ref +2B ref )×(h ref +h 1ref +h 2ref +H Oref )

[0028] ×W ref ×ρ+1.169457

[0029] Among them, K d and K dref are the equivalent height correction coefficients of the designed overflow brick and the reference overflow brick respectively; w and w ref are the overflow groove widths of the designed overflow brick and the reference overflow brick respectively; B and B ref are the overflow trough wall thickness of the designed overflow brick and the reference overflow brick respectively; h and h ref are the overflow trough depths of the designed overflow brick and the reference overflow brick respectively; h 1 and h 1ref are the first height of the inlet section of the designed overflow brick and the reference overflow brick respectively; h 2 and h 2ref are the second heights of the inlet sections of the designed overflow brick and the reference overflow brick respectively; H O and H Oref W and W are the far end crotch heights of the designed overflow brick and the reference overflow brick respectively; ref are the overflow surface widths of the designed overflow brick and the reference overflow brick respectively; ρ is the material density of the designed overflow brick and the reference overflow brick;

[0030] The specific formula for calculating the equivalent thickness of the design overflow brick and the reference overflow brick is:

[0031]

[0032] Among them, b and b ref are the equivalent thickness of the designed overflow brick and the reference overflow brick respectively; H I and H Irefare the proximal crotch heights of the designed overflow brick and the reference overflow brick respectively; θ and θ ref are the overflow slope angles of the designed overflow brick and the reference overflow brick respectively;

[0033] The specific formula for calculating the equivalent height of the design overflow brick and the reference overflow brick is:

[0034]

[0035] Among them, d and d ref are the equivalent heights of the designed overflow brick and the reference overflow brick, respectively;

[0036] The specific formula for calculating the bending stress ratio K of the design overflow brick and the reference overflow brick is:

[0037]

[0038] Calculate the maximum bending stress σ of the overflow brick max The specific formula is:

[0039]

[0040] Calculate the maximum cylinder pressure P of the overflow brick under normal temperature steady state conditions max The specific formula is:

[0041]

[0042] Calculate the maximum bending value Y of the overflow brick under normal temperature steady state conditions max The specific formula is:

[0043]

[0044] Formula (2) is specifically:

[0045]

[0046] Where g is the acceleration due to gravity; G and G ref are the weights of the designed overflow brick and the reference overflow brick plus glass, respectively; S and S ref are the clamping cylinder action areas of the designed overflow brick and the reference overflow brick respectively;

[0047] Based on the ratio of the designed overflow brick bending stress to the maximum bending stress and the ratio of the deformation bending amount to the maximum deformation bending amount being equal, formula (3) is obtained, which is specifically:

[0048]

[0049] Design the overflow brick bending stress σ corresponding to the clamping cylinder pressure P 2 The specific formula is:

[0050]

[0051] Furthermore, the second functional relationship is specifically:

[0052]

[0053] Calculate the Steady-State Creep Rate of Designed Overflow Bricks The specific formula is:

[0054]

[0055] Where, ε is the bending creep rate, in mm / mm; is the steady-state creep rate, in units of mm / mm / hr; σ and T are the bending stress and temperature applied to the overflow brick, respectively; A and Q are constants related to the overflow brick material; n is the applied stress exponent of the steady-state creep rate of the overflow brick; Q=E / R, E is the creep activation energy, and R is the gas constant.

[0056] Furthermore, the specific formula for calculating the creep amount Δ of the designed overflow brick is:

[0057]

[0058] Among them, t W Design duty cycle for overflow bricks.

[0059] A method for controlling the clamping cylinder pressure of overflow bricks during the heating, wetting and plate-leading stages is provided, based on the analytical method for the high-temperature creep of overflow bricks.

[0060] Furthermore, in the heating stage, when the temperature is less than 900°C, the clamping cylinder pressure of the overflow brick is controlled to be 0;

[0061] When 900℃≤temperature<1235℃, the clamping cylinder pressure of the overflow brick is controlled to be 0.5×F 初始 ;

[0062] When 1235℃≤temperature<1265℃, the clamping cylinder pressure of the overflow brick is controlled to be F 初始 ,

[0063] In the wetting stage, the clamping cylinder pressure of the overflow brick is controlled to be F 初始 ,

[0064] In the stage of leading the plate, the clamping cylinder pressure of the overflow brick is controlled to be F 设计 ,

[0065] in,

[0066]

[0067] F 初始 is the initial clamping cylinder pressure, F 设计 is the design clamping cylinder pressure, F max is the maximum cylinder pressure P max The corresponding maximum cylinder pressure, ROUND() is the rounding function, and G is the weight of the designed overflow brick and glass.

[0068] Furthermore, F max The specific formula is:

[0069] F max =P max ×S / g

[0070] Among them, S is the designed overflow brick clamping cylinder action area, and g is the gravitational acceleration.

[0071] Further, when the clamping cylinder pressure reaches F 设计 , and when the creep amount continues to increase, continue to increase the clamping cylinder pressure, while keeping the clamping cylinder pressure ≤ F max .

[0072] Compared with the prior art, the positive and progressive effects of the present invention are:

[0073] The high-temperature creep amount analysis method of the overflow brick provided by the present invention establishes the precise functional relationship between the steady-state creep rate of the overflow brick material and the bending stress and temperature through systematic creep tests, so that the prediction of the creep amount of the overflow brick under a high-temperature working environment is more accurate; through structural simulation and theoretical analysis, the geometric dimensions, material properties and working environment temperature factors of the overflow brick are comprehensively considered, which provides a scientific basis for designing high-strength, low-creep overflow bricks, helps to optimize its structural design, and improves its service life and stability; at the same time, a creep rate and creep amount calculation method based on creep mechanism and material properties is proposed, which provides a quantitative basis for reasonably setting the clamping cylinder pressure during the production process, effectively controls the creep amount of the overflow brick under high-temperature working conditions, and ensures the stable operation of the production line; a standardized high-temperature creep analysis process is established, which makes the evaluation and control of the creep amount of the overflow brick more systematic and standardized, thereby improving the quality of the formed glass substrate, reducing production interruptions and losses caused by creep problems, and improving production efficiency.

[0074] According to the creep analysis results of overflow bricks, reference process suggestions for the clamping cylinder pressure in the heating, wetting and plate introduction stages are provided for the production line. Through reasonable clamping cylinder pressure control, the production process is optimized to further improve the quality of the formed glass substrate. At the same time, equipment damage and premature scrapping caused by excessive creep are avoided, and the service life of overflow bricks is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The drawings in the specification are used to provide further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0076] Figure 1 It is a structural schematic diagram of the overflow system;

[0077] Figure 2 It is a schematic diagram of the structure of overflow pull-down of a glass substrate;

[0078] Figure 3 It is a schematic diagram of the stress structure of the overflow brick bearing the clamping cylinder;

[0079] Figure 4 It is a schematic diagram of the structural parameters of overflow bricks;

[0080] Figure 5 Schematic diagram of the relationship curve between the clamping cylinder pressure corresponding to the overflow brick clamping cylinder pressure and the overflow brick bending stress in the embodiment;

[0081] Figure 6 Schematic diagram of the curve of creep rate and creep amount corresponding to the overflow brick clamping cylinder pressure in the embodiment.

[0082] Among them, 1 is the overflow brick, 2 is the overflow trough, 3 is the glass liquid feeding device, 4 is the root of the overflow brick, and 5 is the drainage plate;

[0083] 6 is the formed glass substrate, 7 is the downward pulling direction of the glass substrate, W G is the width of the glass substrate, W Y is the width of the glass substrate lead;

[0084] P is the pressure of the overflow brick clamping cylinder, G is the weight of the designed overflow brick plus glass;

[0085] B is the overflow groove wall thickness of the overflow brick, W is the overflow surface width, w is the overflow groove width, h is the overflow groove depth of the inlet section, R is the chamfer radius of the overflow brick tip, φ is the overflow weir inclination angle, θ is the overflow slope angle, h 1 is the first height of the overflow brick inlet section, h 2 is the second height of the inlet section, H O H is the far end height of the overflow brick. I It is the proximal crotch height of the overflow brick;

[0086] Curve ① is the creep amount curve, and curve ② is the creep rate curve. DETAILED DESCRIPTION

[0087] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0088] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0089] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0090] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0091] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0092] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0093] The present invention is further described in detail below in conjunction with the accompanying drawings, which are intended to explain the present invention rather than to limit it.

[0094] See also Figure 1 The overflow system is composed of an overflow brick 1 and a glass liquid feeding device 3. An overflow trough 2 is provided in the overflow brick 1, and the bottom of the overflow brick 1 is an overflow brick root 4. When the glass substrate is manufactured by a molten overflow method, the glass liquid melted by the glass melting furnace is supplied to the glass liquid feeding device 3 in the molten overflow molding device in the molding process, and overflows along the overflow trough 2 through both sides of the overflow brick 1, and forms a glass substrate from below the overflow brick root 4.

[0095] As the glass melt is pushed from the proximal end to the distal end of the overflow trough, it is pushed by the mass force and pressure in the running direction, overcomes the laminar viscous resistance and flows downward from the overflow weir. The fluid dynamics equation based on this principle integrates the effects of the above forces and is the basis for the design of the overflow trough. On the vertical surface of the overflow, the mass force and pressure are large enough, and the viscosity is relatively low, the effect of the lateral surface tension is very small, and there is almost no lateral contraction; on the inclined surface, the mass force and pressure components along the inclined surface become significantly smaller, and the viscosity gradually increases, the effect of the lateral surface tension becomes prominent, and a significant lateral contraction occurs. Therefore, a platinum material drainage plate 5 is provided at the proximal and distal ends of the inclined surface of the overflow brick to partially resist the lateral contraction of the glass.

[0096] See also Figure 2 The guide plate serves as the molding basis of the glass substrate. During the process of pulling down the glass substrate, the molded glass substrate 5 moves downward along the glass substrate pulling direction 6. G is the width of the glass substrate, W Y is the width of the glass substrate lead.

[0097] See also Figure 3 The force on the overflow brick support part and gravity G (the weight of the overflow brick plus glass) must establish a balanced relationship to ensure the support strength. The pressure P of the overflow brick clamping cylinder should resist the deformation of the overflow brick by gravity G (the weight of the overflow brick plus glass) as much as possible.

[0098] The present invention provides a high-temperature creep analysis method and application of overflow bricks. A mature overflow brick for glass substrate manufacturing is selected as a design reference. The functional relationship between the deformation bending amount Y and the clamping cylinder pressure P of the reference overflow brick under normal temperature steady-state conditions is obtained through structural simulation (such as ANSYS); based on the structural dimensions of the reference overflow brick and the designed overflow brick, the overflow surface lengths W and W of the reference overflow brick and the designed overflow brick are obtained. ref , equivalent widths b and b ref and equivalent heights d and d ref; Based on the three-point bending stress theory, the bending stress ratio K of the designed overflow brick and the reference overflow brick under the condition of no clamping cylinder is obtained; based on the relationship between the steady-state deformation bending amount of the overflow brick and the clamping cylinder pressure (independent of creep) and related equivalence, the functional relationship between the deformation bending amount Y of the designed overflow brick under normal temperature steady-state conditions and the clamping cylinder pressure P is obtained; based on the proportional relationship between the bending stress and the deformation bending amount of the overflow brick under normal temperature steady-state conditions, the overflow brick bending stress σ of the designed overflow brick corresponding to the clamping cylinder pressure P is obtained; creep tests at different stress levels are carried out on the overflow brick material at different test temperatures, and according to the creep test results, the steady-state creep rate of the overflow brick material is established. Functional relationship between bending stress σ and temperature T; Steady-state creep rate based on overflow brick material The functional relationship between bending stress σ and temperature T is used to obtain the designed overflow brick working environment temperature T W and the steady-state creep rate under the corresponding clamping cylinder pressure P Based on the designed working environment temperature of the overflow brick and the steady-state creep rate under the corresponding clamping cylinder bending stress conditions, the design working period t of the overflow brick is calculated. W The creep amount Δ; establish the reference process conditions for the overflow brick clamping cylinder pressure when the overflow brick is heated, moistened and the plate is drawn. Reasonable clamping cylinder pressure is the basis for effectively controlling the creep amount. The clamping cylinder pressure before the overflow brick is drawn (heating and moistening) is recommended as the initial value, and the clamping cylinder pressure after the plate is drawn is recommended as the design value; after the overflow brick creep amount continues to increase, and considering the high temperature strength of the overflow brick, the cylinder clamping force should not be too large, and it is recommended not to exceed the theoretical limit pressure.

[0099] The present invention is described in further detail below in conjunction with embodiments:

[0100] A method for analyzing the high temperature creep of overflow bricks comprises the following steps:

[0101] S1. Select the overflow brick used for mature glass substrate manufacturing as the reference overflow brick. Through simulation, establish the first functional relationship between the deformation bending amount Y and the clamping cylinder pressure P of the reference overflow brick under normal temperature steady-state conditions, and obtain the maximum cylinder pressure P of the reference overflow brick under normal temperature steady-state conditions. maxref and the maximum bending amount Y maxref ;

[0102] Specifically, the first functional relationship is:

[0103]

[0104] Among them, P maxref Y is the maximum cylinder pressure of the reference overflow brick under normal temperature steady state conditions, corresponding to the bending amount of 0; maxref It is the maximum bending amount of the reference overflow brick under normal temperature and steady state conditions, and the corresponding cylinder pressure is 0.

[0105] S2. Construct a designed overflow brick that is equivalent to the reference overflow brick, obtain the structural parameters of the designed overflow brick and the reference overflow brick, and calculate the bending stress ratio K of the designed overflow brick and the reference overflow brick and the maximum bending stress σ of the designed overflow brick based on the structural parameters. max ; Based on the first functional relationship, combined with the bending stress ratio K and the maximum bending stress σ max , Maximum cylinder pressure P maxref and the maximum bending amount Y maxref , calculate and design the overflow brick bending stress σ corresponding to the clamping cylinder pressure P 2 ;

[0106] Among them, the structural parameters include the first structural parameters and the second structural parameters. The first structural parameters include: overflow groove width, overflow groove wall thickness, overflow groove depth, inlet section first height, inlet section second height, distal crotch height, overflow surface width and material density. The second structural parameters include: proximal crotch height and overflow inclination angle. For the specific location of the structural parameters, see Figure 4 .

[0107] Calculate the bending stress ratio K of the designed overflow brick and the reference overflow brick and the maximum bending stress σ of the designed overflow brick max The specific steps include:

[0108] Calculating the equivalent height correction coefficient of the designed overflow brick and the reference overflow brick according to the first structural parameter;

[0109] Calculating the equivalent thickness of the designed overflow brick and the reference overflow brick according to the first structural parameter and the second structural parameter;

[0110] According to the first structural parameter, in combination with the calculated equivalent height correction coefficient and equivalent thickness, the equivalent height of the designed overflow brick and the reference overflow brick is calculated;

[0111] According to the overflow surface width and equivalent height of the designed overflow brick and the reference overflow brick, the bending stress ratio K of the designed overflow brick and the reference overflow brick is calculated; according to the overflow surface width and equivalent height of the designed overflow brick, the maximum bending stress σ of the designed overflow brick is calculated max ;

[0112] Calculate and design the overflow brick bending stress σ corresponding to the clamping cylinder pressure P 2 The specific steps include:

[0113] Get the weight of the designed overflow brick and the reference overflow brick plus glass and the clamping cylinder action area, combined with the maximum cylinder pressure P maxref , calculate the maximum cylinder pressure P under normal temperature steady state conditions of the overflow brick design maxBased on the overflow surface width of the designed overflow brick and the reference overflow brick, combined with the bending stress ratio K and the maximum bending amount Y of the reference overflow brick under normal temperature steady state conditions maxref , calculate the maximum bending value Y of the overflow brick under normal temperature steady state conditions max ;

[0114] Based on the equivalent relationship between the designed overflow brick and the reference overflow brick, the maximum bending amount Y max and the maximum cylinder pressure P max Substituting into the first functional relationship, we get formula (2). Based on the principle that the ratio of the designed overflow brick bending stress to the maximum bending stress and the ratio of the deformation bending amount to the maximum deformation bending amount are equal, we get formula (3). Combining formulas (2) and (3) we get the overflow brick bending stress σ of the designed overflow brick corresponding to the clamping cylinder pressure P: 2 ;

[0115] Specifically: The specific formula for calculating the equivalent height correction coefficient of the design overflow brick and the reference overflow brick is: K d =-8.59468×10 -6 ×(w+2B)×(h+h 1 +h 2 +H O )×W×ρ+1.169457

[0116] K dref =-8.59468×10 -6 ×(w ref +2B ref )×(h ref +h 1ref +h 2ref +H Oref )

[0117] ×W ref ×ρ+1.169457

[0118] Among them, K d and K dref are the equivalent height correction coefficients of the designed overflow brick and the reference overflow brick respectively; w and w ref are the overflow groove widths of the designed overflow brick and the reference overflow brick respectively; B and B ref are the overflow trough wall thickness of the designed overflow brick and the reference overflow brick respectively; h and h ref are the overflow trough depths of the designed overflow brick and the reference overflow brick respectively; h 1 and h 1ref are the first height of the inlet section of the designed overflow brick and the reference overflow brick respectively; h 2 and h 2ref are the second heights of the inlet sections of the designed overflow brick and the reference overflow brick respectively; H O and HOref W and W are the far end crotch heights of the designed overflow brick and the reference overflow brick respectively; ref are the overflow surface widths of the designed overflow brick and the reference overflow brick respectively; ρ is the material density of the designed overflow brick and the reference overflow brick;

[0119] The specific formula for calculating the equivalent thickness of the design overflow brick and the reference overflow brick is:

[0120]

[0121] Among them, b and b ref are the equivalent thickness of the designed overflow brick and the reference overflow brick respectively; H I and H Iref are the proximal crotch heights of the designed overflow brick and the reference overflow brick respectively; θ and θ ref are the overflow slope angles of the designed overflow brick and the reference overflow brick respectively;

[0122] The specific formula for calculating the equivalent height of the design overflow brick and the reference overflow brick is:

[0123]

[0124] Among them, d and d ref are the equivalent heights of the designed overflow brick and the reference overflow brick, respectively;

[0125] The specific formula for calculating the bending stress ratio K of the design overflow brick and the reference overflow brick is:

[0126]

[0127] Calculate the maximum bending stress σ of the overflow brick max The specific formula is:

[0128]

[0129] Calculate and design the maximum cylinder pressure P of the overflow brick under normal temperature and steady state conditions max The specific formula is:

[0130]

[0131] Calculate the maximum bending value Y of the overflow brick under normal temperature steady state conditions max The specific formula is:

[0132]

[0133] Formula (2) is specifically:

[0134]

[0135] Where g is the acceleration due to gravity; G and Gref are the weights of the designed overflow brick and the reference overflow brick plus glass, respectively; S and S ref are the clamping cylinder action areas of the designed overflow brick and the reference overflow brick respectively;

[0136] Based on the ratio of the designed overflow brick bending stress to the maximum bending stress and the ratio of the deformation bending amount to the maximum deformation bending amount being equal, formula (3) is obtained, which is specifically:

[0137]

[0138] Design the overflow brick bending stress σ corresponding to the clamping cylinder pressure P 2 The specific formula is:

[0139]

[0140] S3. Conduct creep tests based on overflow brick materials and establish steady-state creep rate based on test data The second functional relationship between bending stress σ and temperature T; obtain the working environment temperature T of the designed overflow brick W Based on the second functional relationship, the overflow brick bending stress σ corresponding to the clamping cylinder pressure P is designed. 2 ; Get the steady-state creep rate of the designed overflow brick

[0141] Among them, the second functional relationship is specifically:

[0142]

[0143] Calculate the Steady-State Creep Rate of Designed Overflow Bricks The specific formula is:

[0144]

[0145] Where, ε is the bending creep rate, in mm / mm; is the steady-state creep rate in mm / mm / hr; σ and T are the bending stress and temperature applied to the overflow brick, respectively; A and Q are constants related to the overflow brick material and can be measured by the three-point bending method; n is the applied stress exponent of the steady-state creep rate of the overflow brick; Q=E / R, E is the creep activation energy, and R is the gas constant.

[0146] S4. Steady-state creep rate based on designed overflow bricks Calculate the creep amount Δ of the designed overflow brick.

[0147] The specific formula for calculating the creep amount Δ of the designed overflow brick is:

[0148]

[0149] Among them, t W Design duty cycle for overflow bricks.

[0150] Specifically, in this embodiment, the maximum cylinder pressure P maxref =0.638317951568155MPa, maximum bending amount Y maxref =13.39913μm.

[0151] The overflow surface width of the reference overflow brick is 2008mm; the equivalent thickness of the reference overflow brick is 221.82mm; the equivalent height of the reference overflow brick is 608.74mm; the effective area of ​​the reference overflow brick clamping cylinder is: 0.0230640590156628m 2 .

[0152] The overflow surface width of the overflow brick is designed to be 3316mm; the equivalent thickness of the overflow brick is designed to be 238.27mm; the equivalent height of the overflow brick is designed to be 973.38mm; the effective area of ​​the clamping cylinder of the overflow brick is designed to be 0.0275962383479131m 2 .

[0153] The overflow brick material density of the designed overflow brick and the reference overflow brick is 4430Kg / m 3 .

[0154] Based on the above-mentioned analytical method for the high-temperature creep of overflow bricks, the present invention also provides a control method for designing the clamping cylinder pressure of overflow bricks in the heating, wetting and plate-leading stages.

[0155] Specifically, in the heating stage, when the temperature is less than 900°C, the clamping cylinder pressure of the overflow brick is controlled to be 0;

[0156] When 900℃≤temperature<1235℃, the clamping cylinder pressure of the overflow brick is controlled to be 0.5×F 初始 ;

[0157] When 1235℃≤temperature<1265℃, the clamping cylinder pressure of the overflow brick is controlled to be F 初始 ,

[0158] In the wetting stage, the clamping cylinder pressure of the overflow brick is controlled to be F 初始 ,

[0159] In the stage of leading the plate, the clamping cylinder pressure of the overflow brick is controlled to be F 设计 ,

[0160] in,

[0161]

[0162]

[0163] F 初始 is the initial clamping cylinder pressure, F 设计 is the design clamping cylinder pressure, F max is the maximum cylinder pressure P max The corresponding maximum cylinder pressure, ROUND() is the rounding function, G is the weight of the designed overflow brick plus glass,

[0164] F max The specific formula is:

[0165] F max =P max ×S / g

[0166] Among them, S is the designed overflow brick clamping cylinder action area, g is the gravity acceleration;

[0167] When the clamping cylinder pressure reaches F 设计 , and when the creep amount continues to increase, continue to increase the clamping cylinder pressure, while keeping the clamping cylinder pressure ≤ F max .

[0168] In this embodiment, the weight of the overflow brick plus the glass is G = 3407 kg, F max =4261Kgf,

[0169] F 初始 =3600Kgf, F 设计 =4100Kgf, where Kgf is kilogram-force.

[0170]

[0171] Based on the analysis of the high temperature creep of overflow bricks, a reference process for the clamping cylinder pressure of overflow bricks during heating, wetting and plate introduction stages is provided for the production line, specifically:

[0172] 1. Heating stage: before heating from room temperature to 900℃, the pressure of the overflow brick clamping cylinder is 0; before heating from 900℃ to 1235℃, the pressure of the overflow brick clamping cylinder is 1800Kgf;

[0173] The temperature rises from 1235℃ to 1265℃, and the overflow brick clamping cylinder pressure is 3600Kgf.

[0174] 2. Wetting stage: The pressure of the overflow brick clamping cylinder is 3600Kgf.

[0175] 3. Plate leading stage: The pressure of the overflow brick clamping cylinder is 4100Kgf.

[0176] 4. After the subsequent overflow brick creep continues to increase, increase the overflow brick clamping cylinder pressure in a timely manner (according to the specific process effect), but it should not exceed 4261Kgf.

[0177] See also Figure 5 , is a schematic diagram of the relationship curve between the clamping cylinder pressure and the overflow brick bending stress corresponding to the overflow brick clamping cylinder pressure in this embodiment, wherein the blue is the clamping cylinder pressure curve and the red is the overflow brick bending stress curve. Figure 6 , which is a data table and a curve diagram of creep rate and creep amount corresponding to the pressure of the clamping cylinder of the overflow brick in the embodiment. See Table 1, which is the data of creep rate and creep amount corresponding to the pressure of the clamping cylinder of the overflow brick in this embodiment.

[0178] Table 1

[0179]

[0180] Combination Figures 5-6 From Table 1, it can be seen that under the conditions of an average working environment temperature of about 1207°C and an average production cycle of 40 months, when the clamping cylinder pressure is 4261Kgf, the clamping cylinder pressure is 1.513MP, the overflow brick bending stress is 0, and the creep rate is 0; when the clamping cylinder pressure is 4100Kgf, the clamping cylinder pressure is 1.456MP, the overflow brick bending stress is 0.028MP, and the creep rate is 5.85878E-08mm / mm / hr; when the clamping cylinder pressure is 3600Kgf, the clamping cylinder pressure is 1.278MP, the overflow brick bending stress is 0.114MP, and the creep rate is 3.57119E-07mm / mm / hr.

[0181] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for analyzing the high temperature creep of overflow bricks, characterized in that: The following steps are involved: S1. Select the overflow brick used for mature glass substrate manufacturing as the reference overflow brick. Through simulation, establish the first functional relationship between the deformation bending amount Y and the clamping cylinder pressure P of the reference overflow brick under normal temperature steady-state conditions, and obtain the maximum cylinder pressure P of the reference overflow brick under normal temperature steady-state conditions. maxref and the maximum bending amount Y maxref ; S2. Construct a designed overflow brick that is equivalent to the reference overflow brick, obtain the structural parameters of the designed overflow brick and the reference overflow brick, and calculate the bending stress ratio K of the designed overflow brick and the reference overflow brick and the maximum bending stress σ of the designed overflow brick based on the structural parameters. max ; Based on the first functional relationship, combined with the bending stress ratio K and the maximum bending stress σ max , Maximum cylinder pressure P maxref and the maximum bending amount Y maxref , calculate and design the overflow brick bending stress σ2 corresponding to the clamping cylinder pressure P; S3. Conduct creep tests based on overflow brick materials and establish steady-state creep rate based on test data The second functional relationship between bending stress σ and temperature T; obtain the working environment temperature T of the designed overflow brick W Based on the second functional relationship, combined with the overflow brick bending stress σ2 corresponding to the clamping cylinder pressure P of the designed overflow brick, the steady-state creep rate of the designed overflow brick is obtained: S4. Steady-state creep rate based on designed overflow bricks Calculate the creep amount Δ of the designed overflow brick.

2. The high temperature creep analysis method of overflow brick according to claim 1, characterized in that: The first functional relationship is specifically: 。 3. The high temperature creep analysis method of overflow brick according to claim 1, characterized in that: The structural parameters include a first structural parameter and a second structural parameter, wherein the first structural parameter includes: overflow groove width, overflow groove wall thickness, overflow groove depth, inlet section first height, inlet section second height, distal crotch height, overflow surface width and material density, and the second structural parameter includes: proximal crotch height and overflow inclination angle; Calculate the bending stress ratio K of the designed overflow brick and the reference overflow brick and the maximum bending stress σ of the designed overflow brick max The specific steps include: Calculating the equivalent height correction coefficient of the designed overflow brick and the reference overflow brick according to the first structural parameter; Calculating the equivalent thickness of the designed overflow brick and the reference overflow brick according to the first structural parameter and the second structural parameter; According to the first structural parameter, in combination with the calculated equivalent height correction coefficient and equivalent thickness, the equivalent height of the designed overflow brick and the reference overflow brick is calculated; According to the overflow surface width and equivalent height of the designed overflow brick and the reference overflow brick, the bending stress ratio K of the designed overflow brick and the reference overflow brick is calculated; according to the overflow surface width and equivalent height of the designed overflow brick, the maximum bending stress σ of the designed overflow brick is calculated max ; The calculation and design of the overflow brick bending stress σ2 corresponding to the clamping cylinder pressure P specifically includes the following steps: Obtain the weight of the designed overflow brick and the reference overflow brick plus glass and the clamping cylinder action area, combined with the maximum cylinder pressure P maxref , calculate the maximum cylinder pressure P of the overflow brick under normal temperature steady state conditions max Based on the overflow surface width of the designed overflow brick and the reference overflow brick, combined with the bending stress ratio K and the maximum bending amount Y of the reference overflow brick under normal temperature steady state conditions maxref , calculate the maximum bending value Y of the overflow brick under normal temperature steady state conditions max ; Based on the equivalent relationship between the designed overflow brick and the reference overflow brick, the maximum bending amount Y max and the maximum cylinder pressure P max Substituting into the first functional relationship, we get formula (2). Based on the principle that the ratio of the designed overflow brick bending stress to the maximum bending stress and the ratio of the deformation bending amount to the maximum deformation bending amount are equal, we get formula (3). Combining formulas (2) and (3) we get the overflow brick bending stress σ2 of the designed overflow brick corresponding to the clamping cylinder pressure P.

4. The high temperature creep analysis method of overflow brick according to claim 3 is characterized in that: The specific formula for calculating the equivalent height correction factor of the design overflow brick and the reference overflow brick is: K d =-8.59468×10 -6 ×(w+2B)×(h+h1+h2+H O )×W×ρ+1.169457 K dref =-8.59468×10 -6 ×(w ref +2B ref )×(h ref +h 1ref +h 2ref +H Oref ) ×W ref ×ρ+1.169457 Among them, K d and K dref are the equivalent height correction coefficients of the designed overflow brick and the reference overflow brick respectively; w and w ref are the overflow groove widths of the designed overflow brick and the reference overflow brick respectively; B and B ref are the overflow trough wall thickness of the designed overflow brick and the reference overflow brick respectively; h and h ref are the overflow trough depths of the designed overflow brick and the reference overflow brick respectively; h1 and h 1ref are the first height of the inlet section of the designed overflow brick and the reference overflow brick respectively; h2 and h 2ref are the second heights of the inlet sections of the designed overflow brick and the reference overflow brick respectively; H o and H oref W and W are the far end crotch heights of the designed overflow brick and the reference overflow brick respectively; ref are the overflow surface widths of the designed overflow brick and the reference overflow brick respectively; ρ is the material density of the designed overflow brick and the reference overflow brick; The specific formula for calculating the equivalent thickness of the design overflow brick and the reference overflow brick is: Among them, b and b ref are the equivalent thickness of the designed overflow brick and the reference overflow brick respectively; H I and H Iref are the proximal crotch heights of the designed overflow brick and the reference overflow brick respectively; θ and θ ref are the overflow slope angles of the designed overflow brick and the reference overflow brick respectively; The specific formula for calculating the equivalent height of the design overflow brick and the reference overflow brick is: Among them, d and d ref are the equivalent heights of the designed overflow brick and the reference overflow brick, respectively; The specific formula for calculating the bending stress ratio K of the design overflow brick and the reference overflow brick is: Calculate the maximum bending stress σ of the overflow brick max The specific formula is: Calculate the maximum cylinder pressure P of the overflow brick under normal temperature steady state conditions max The specific formula is: Calculate the maximum bending value Y of the overflow brick under normal temperature steady state conditions max The specific formula is: Formula (2) is specifically: Where g is the acceleration due to gravity; G and G ref are the weights of the designed overflow brick and the reference overflow brick plus glass, respectively; S and S ref are the clamping cylinder action areas of the designed overflow brick and the reference overflow brick respectively; Based on the ratio of the designed overflow brick bending stress to the maximum bending stress and the ratio of the deformation bending amount to the maximum deformation bending amount being equal, formula (3) is obtained, which is specifically: The specific formula for designing the overflow brick bending stress σ2 corresponding to the clamping cylinder pressure P is: 。 5. The high temperature creep analysis method of overflow brick according to claim 4, characterized in that: The second functional relationship is specifically: Calculate the Steady-State Creep Rate of Designed Overflow Bricks The specific formula is: Where, ε is the bending creep rate, in mm / mm; is the steady-state creep rate, in units of mm / mm / hr; σ and T are the bending stress and temperature applied to the overflow brick, respectively; A and Q are constants related to the overflow brick material; n is the applied stress exponent of the steady-state creep rate of the overflow brick; Q=E / R, E is the creep activation energy, and R is the gas constant.

6. The high temperature creep analysis method of overflow brick according to claim 5, characterized in that: The specific formula for calculating the creep amount Δ of the designed overflow brick is: Among them, t W Design duty cycle for overflow bricks.

7. A method for controlling the clamping cylinder pressure of overflow bricks during the heating, wetting and plate-leading stages, characterized in that: A method for analyzing the high temperature creep of overflow bricks according to any one of claims 3 to 6.

8. The method for controlling the clamping cylinder pressure of overflow bricks during the heating, wetting and plate-leading stages according to claim 7 is characterized in that: In the heating stage, when the temperature is less than 900℃, the clamping cylinder pressure of the overflow brick is controlled to be 0; When 900℃≤temperature<1235℃, the clamping cylinder pressure of the overflow brick is controlled to be 0.5×F 初始 ; When 1235℃≤temperature<1265℃, the clamping cylinder pressure of the overflow brick is controlled to be F 初始 , In the wetting stage, the clamping cylinder pressure of the overflow brick is controlled to be F 初始 , In the stage of leading the plate, the clamping cylinder pressure of the overflow brick is controlled to be F 设计 , in, F 初始 is the initial clamping cylinder pressure, F 设计 is the design clamping cylinder pressure, F max is the maximum cylinder pressure P max The corresponding maximum cylinder pressure, ROUND() is the rounding function, and G is the weight of the designed overflow brick and glass.

9. The method for controlling the clamping cylinder pressure of overflow bricks during the heating, wetting and plate-leading stages according to claim 8 is characterized in that: F max The specific formula is: F max =P max ×S / g Among them, S is the designed overflow brick clamping cylinder action area, and g is the gravitational acceleration.

10. The method for controlling the clamping cylinder pressure of overflow bricks during the heating, wetting and plate-leading stages according to claim 9 is characterized in that: When the clamping cylinder pressure reaches F 设计 , and when the creep amount continues to increase, continue to increase the clamping cylinder pressure, while keeping the clamping cylinder pressure ≤ F max .

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