JP2017178733A - Production method of glass sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling a temperature efficiently without occurrence of abnormal temperature rise, in introduction of molten glass from a melting furnace to a processing unit in the initial operation.SOLUTION: When raising a temperature of a processing unit by introducing molten glass from a melting furnace to the processing unit at the time of operation start, the processing unit is maintained at a stand-by temperature Tlower than an operation temperature T, and when an introduction rate of the molten glass at which a heat quantity (A) brought into the processing unit by the molten glass and a heat release amount (B) from the processing unit satisfy an inequality (A)<(B) is expressed as an introduction standard flow rate X(kg/s), a flow rate of the molten glass is regulated based on the introduction standard flow rate Xin each prescribed time, when introducing the molten glass, to thereby heat the processing unit up to the operation temperature T.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a glass plate manufacturing method and a manufacturing apparatus.

  In the production of a glass plate, a glass raw material is melted in a melting furnace to produce a molten glass, which is sent through a glass supply pipe to a molten glass processing apparatus such as a clarification pipe or a stirring tank. The molten glass sent to the molten glass processing apparatus is clarified by a clarification tube, stirred by a stirrer in a stirring tank to homogenize glass components, and then sent to a molded body to be formed into sheet glass.

  In the initial stage of operation of a glass plate production apparatus equipped with a melting furnace, a processing apparatus and a molded body, a glass supply pipe is introduced while introducing high-temperature molten glass through the glass supply pipe from the melting furnace to the processing apparatus and the forming pair in order. And the temperature of the processing apparatus is controlled by heating.

In order to heat these apparatuses while introducing high-temperature molten glass into the supply pipe and the processing apparatus at the start of operation, it is necessary to control the introduction speed of the molten glass so as not to cause an abnormal temperature rise of the apparatus. When high temperature molten glass flows out from the melting furnace to the supply pipe, if the temperature of the equipment rises rapidly and the temperature rise function of the equipment is abnormal, it is necessary to take measures such as temporarily adjusting the equipment temperature with the cooling function It becomes.
However, such measures are disadvantageous not only in that it takes a long time to obtain a stable operation, but also in that the temperature of the processing apparatus is controlled to form the temperature history of the target molten glass. Affects quality.

  Regarding a molten glass supply pipe and a clarification pipe, a supply pipe and a clarification pipe made of platinum or a platinum alloy are known (Patent Document 1). Moreover, it discloses about the temperature control required for the molten glass processing apparatus comprised with platinum or a platinum alloy, and the temperature control of a molten glass (patent document 2).

Special table 2008-539162 Japanese Patent Laying-Open No. 2015-199642

  As described above, at the start of the operation of the glass plate manufacturing apparatus, in order to introduce high-temperature molten glass sequentially into the clarification tube and the stirring tank through the glass supply tube, the amount of molten glass introduced (introduction rate) is controlled. However, it is necessary to manage the temperature rise of each device.

  However, for each of the molten glass processing equipment, including the supply pipe, clarification pipe, and stirring tank, the amount of molten glass introduced (introduction speed) is appropriate based on the equipment structure and materials, the temperature of the molten glass, and the installation conditions of each equipment. It is not easy to control the heating of each device while controlling them.

  The purpose of the present invention is to introduce the molten glass from the melting furnace to the processing device sequentially in the initial stage of operation from the start of operation until reaching stable operation, without causing an abnormal temperature rise of the treatment device. An object of the present invention is to provide a glass plate manufacturing method and a glass plate manufacturing apparatus that can control the temperature of the apparatus while maintaining the (introduction speed) optimally and can efficiently reach a stable operation of the processing apparatus.

[1] A melting step of melting a glass raw material in a melting furnace to produce a molten glass, a molten glass processing step of processing the molten glass using a processing apparatus for processing the molten glass made in the melting furnace, A glass plate manufacturing method including a forming step of forming a sheet glass by forming the molten glass processed in the processing step,
At the start of operation, the molten glass from the melting furnace is introduced into the processing apparatus and the processing apparatus is heated to maintain the processing apparatus at a standby temperature T ₂ lower than the operating temperature T _1. Assuming that the introduction rate of molten glass at which the amount of heat (A) brought into the processing apparatus and the heat dissipation amount (B) of the processing apparatus is (A) <(B) is the introduction reference flow rate X ₀ (kg / s), molten glass When the glass plate is introduced, the flow rate of the molten glass is regulated every predetermined time based on the introduction reference flow rate X ₀ , and the processing apparatus is heated to the operating temperature T _1. Method.

[2] The processing apparatus includes: a refining tube for defoaming O ₂ contained in the molten glass to clarify the molten glass; a stirring tank for homogenizing the molten glass; and the molten glass from the melting furnace to the refining tube. A glass supply pipe 1 for transferring at a predetermined temperature, a glass supply pipe 2 for transferring molten glass from the clarification pipe to the stirring tank at a predetermined temperature, and transferring the molten glass from the stirring tank to the molded body at a predetermined temperature. A glass supply pipe 3
When the molten glass is caused to flow out of the melting furnace at the start of operation and the molten glass is introduced into the glass supply pipe 1, the clarification pipe, the glass supply pipe 2, the stirring tank, and the glass supply pipe 3 in this order, each device, the flow rate of the molten glass is regulated by the introduction reference flow rate X ₀ respectively, are heated to the respective operating temperature T _1, the manufacturing method of a glass plate according to [1].

[3] The processing unit, when introducing the molten glass, so as not to exceed the introduction reference flow X _0, the flow rate of the molten glass is regulated, is heated to operating temperature T _1, to claim 1 or 2 The manufacturing method of the glass plate of description.

[4] The manufacturing method according to any one of [1] to [3], wherein the heat dissipation amount (B) of the processing apparatus is due to natural heat dissipation.

[5] A melting furnace for melting glass raw material to produce molten glass, a heating means, a processing apparatus for processing the molten glass made in the melting furnace, and a molten glass processed by the processing apparatus. A molding apparatus for forming a sheet glass by molding;
With
At the start of operation, the molten glass from the melting furnace is introduced into the processing apparatus and the processing apparatus is heated to maintain the processing apparatus at a standby temperature T ₂ lower than the operating temperature T _1. Assuming that the introduction rate of molten glass at which the amount of heat (A) brought into the processing apparatus and the heat dissipation amount (B) of the processing apparatus is (A) <(B) is the introduction reference flow rate X ₀ (kg / s), molten glass When the process is introduced, the flow rate of the molten glass is regulated every predetermined time based on the introduction reference flow rate X ₀ , and the processing device is heated to the operation temperature T ₁ by the heating means. Glass plate manufacturing equipment.

[6] The processing apparatus includes: a refining tube for defoaming O ₂ contained in the molten glass to clarify the molten glass; a stirring tank for homogenizing the molten glass; and the molten glass from the melting furnace to the refining tube. A glass supply pipe 1 for transferring at a predetermined temperature, a glass supply pipe 2 for transferring molten glass from the clarification pipe to the stirring tank at a predetermined temperature, and transferring the molten glass from the stirring tank to the molded body at a predetermined temperature. A glass supply pipe 3
When the molten glass is caused to flow out of the melting furnace at the start of operation and the molten glass is introduced into the glass supply pipe 1, the clarification pipe, the glass supply pipe 2, the stirring tank, and the glass supply pipe 3 in this order, each device, the flow rate of molten glass is regulated by the introduction reference flow rate X ₀ respectively, are heated to the respective operating temperature T _1, the manufacturing apparatus of glass plate according to [5].

[7] The processing unit, when introducing the molten glass, so as not to exceed the introduction reference flow X _0, the flow rate of the molten glass is regulated, is heated to operating temperature T _1, [1] or [2 ] The manufacturing apparatus of the glass plate of description.

According to the present invention, the introduction of the molten glass to the processing unit from the operation initial melting furnace, based on the introduction reference flow X _0, rate of introduction is optimally maintained. Since the introduction speed of the molten glass is optimally controlled, the temperature control of the processing apparatus in the initial stage of operation can be efficiently controlled without causing a temperature increase abnormality.

It is a figure which shows an example of the process of the manufacturing method of the glass substrate of this invention. It is a figure which shows typically an example of the apparatus which performs the melting process-cutting process in the manufacturing method of the glass substrate of this invention. It is an image figure which shows the relationship of the temperature management (standby temperature, operation temperature) in the introduction control method of the molten glass at the time of the operation start which concerns on this invention. It is an image figure which shows the relationship (A) <(B) of the amount of heat (A) brought into the processing apparatus in the introduction control method of the molten glass at the time of the operation start which concerns on this invention, and the heat dissipation (B) of the said processing apparatus. It is a figure which shows typically an example of the processing apparatuses 1 to 5 of the molten glass which concern on this invention. It is a figure which shows typically the whole which is an image figure which shows the relationship of the temperature management (standby temperature, operation temperature) of temperature rising control of the processing apparatus (1 to 5) of the molten glass which concerns on this invention.

  Hereafter, the manufacturing method and manufacturing apparatus of the glass substrate of this embodiment, and a stirring tank are demonstrated. FIG. 1 is a diagram showing an example of steps of a method for producing a glass substrate according to the present invention.

(1) Overview of Manufacturing Method of Glass Substrate The manufacturing method of the glass substrate includes a melting step (ST1), a clarification step (ST2), a homogenization step (ST3), a supply step (ST4), and a molding step ( ST5), a slow cooling step (ST6), and a cutting step (ST7) are mainly included. In addition to this, a plurality of glass substrates having a cutting and grinding process, a cleaning process, an inspection process, a packing process, and the like and stacked in the packing process are transported to a supplier.

  The melting step (ST1) is performed in a melting tank. In the melting step, molten glass is made by introducing a glass raw material to the liquid surface of the molten glass stored in the melting tank. Furthermore, molten glass is poured from the outlet provided at the bottom of the melting tank toward the subsequent process.

The melting step (ST1) is performed in a melting furnace. In a melting furnace, a glass raw material is put into a liquid surface of molten glass stored in a melting furnace and heated to make molten glass. Furthermore, molten glass is flowed toward the downstream process from the outlet provided in one bottom part of the inner side wall of the melting furnace.
In addition to the method in which electricity flows through the molten glass itself and heats itself by heating, the glass raw material can be melted by supplementing a flame with a burner. A clarifier is added to the glass raw material. As a fining agent, a metal oxide of a type that releases oxygen by a reduction reaction at a high temperature, such as SnO ₂ , As ₂ O ₃ , Sb ₂ O ₃ , and Fe ₂ O ₃ , is known, but is not particularly limited. However, the use of As ₂ O ₃ as a clarifying agent is not desirable from the viewpoint of reducing environmental burden.

The clarification step (ST2) is performed at least in the clarification tank. In the clarification step, first, the molten glass in the clarification tank is heated to cause a reductive reaction in the clarifier contained in the molten glass to generate O ₂ . This O ₂ is absorbed by bubbles containing CO ₂ , SO _2, N _2, etc. contained in the molten glass due to decomposition reaction of the glass raw material, impurities in the glass raw material, entrainment of the atmosphere during melting, etc. As a result, the bubble diameter of the bubbles in the molten glass is enlarged, and the rising speed of the bubbles is increased. By improving the rising speed of the bubbles, the bubbles are lifted to the liquid surface of the molten glass to promote defoaming. That is, the bubbles that have risen to the liquid surface of the molten glass are broken at the liquid surface, and the gas contained in the bubbles is released into the gas phase space in the clarification tank.
Thereafter, the temperature of the molten glass is lowered to cause the fining agent to oxidize and reabsorb O ₂ in the molten glass. The resorption of the O _2, the small bubbles in the molten glass that has not been degassed, together have a reduced O ₂ is degassing the glass temperature of Awanai, gas pressure in the small bubbles is reduced, the reduction Disappear. In addition, a clarification pipe | tube is provided with the vent pipe connected to air | atmosphere in order to discharge | release the gas discharge | released from the molten glass to the gaseous-phase space to air | atmosphere.

In the homogenization step (ST3), the glass component is homogenized by stirring the molten glass in the stirring tank supplied through the pipe extending from the clarification pipe using a stirrer. Thereby, the composition unevenness of the glass which is a cause of striae or the like can be reduced.
In the supply step (ST4), the molten glass is supplied to the molding apparatus through a pipe extending from the stirring tank.

In the molding apparatus, a molding step (ST5) and a slow cooling step (ST6) are performed.
In the forming step (ST5), the molten glass is formed into a sheet glass to make a flow of the sheet glass. For forming, an overflow downdraw method is used.
In the slow cooling step (ST6), the sheet glass that has been formed and flowed is cooled to a desired thickness, so that internal distortion does not occur and warpage does not occur.
In the cutting step (ST7), the sheet glass supplied from the forming device is cut into a predetermined length in the cutting device to obtain a plate-like glass substrate. The cut glass substrate is further cut into a predetermined size to produce a glass substrate having a target size. After this, the end surface of the glass substrate is ground and polished, the glass substrate is cleaned, and after checking for abnormal defects such as bubbles, the glass substrate that has passed the inspection is packed as the final product. The

  Drawing 2 is a figure showing typically an example of the manufacture device of the glass substrate which performs the melting process (ST1)-cutting process (ST7) in this embodiment. As shown in FIG. 2, the apparatus mainly includes a melting apparatus 100, a forming apparatus 200, and a cutting apparatus 300. The melting apparatus 100 includes a melting furnace 101, a clarification tube 102, a stirring tank 103, and glass supply tubes 104, 105, and 106.

In the melting apparatus 101 shown in FIG. 2, the glass raw material is charged using the bucket 101d, but the raw material charging method is not limited, and a screw feeder type or bush plate type charging machine may be used.
In the clarification tube 102, the temperature of the molten glass MG is adjusted, and the clarification of the molten glass MG is performed using the oxidation-reduction reaction of the clarifier. Further, in the stirring vessel 103, the molten glass MG is stirred and homogenized by the stirrer 103a. In the forming apparatus 200, the sheet glass SG is formed from the molten glass MG by the overflow down draw method using the formed body 210.
A flow path of the molten glass MG from the melting furnace 101 to the molding apparatus 200 shown in FIG. 2, specifically, a glass supply pipe 104, a clarification pipe 102, a glass supply pipe 105, a stirring tank 103, and a glass supply pipe 106. At least a part of the inner surface of the flow path forming the flow path of the molten glass MG is made of platinum or a platinum alloy.

(2) Glass substrate Hereinafter, an embodiment of a method for producing a glass substrate according to the present invention will be described.
The glass substrate manufactured in the embodiment of the present invention is, for example, a glass substrate for flat panel display or a glass substrate for curved panel display, and is suitable as a glass substrate for liquid crystal display or a glass substrate for organic EL display, for example. is there. In addition, the glass substrate can also be used as a display for a portable terminal device, a cover glass for a housing, a touch panel plate, a glass substrate for a solar cell, or a cover glass. Particularly, it is suitable for a glass substrate for liquid crystal display. Panel manufacturing such as LTPS (low temperature polysilicon) TFT, oxide semiconductor TFT, IGZO (Indium-Gallium-Zinc-Oxide) TFT display glass substrate, etc., which are required to have particularly low thermal shrinkage. It can be suitably used for products that require high temperature treatment in the process.

Although the glass substrate manufactured in this embodiment is not particularly limited, for example, the vertical dimension and the horizontal dimension are 500 mm to 3500 mm, 1500 mm to 3500 mm, 1800 to 3500 mm, 2000 mm to 3500 mm, etc., and 2000 mm to 3500 mm. Preferably there is.
The thickness of the glass substrate is, for example, 0.01 mm to 1.1 mm. More preferably, it is a very thin rectangular plate of 0.75 mm or less, and for example, a thickness of 0.55 mm or less, more preferably 0.45 mm or less is more preferable. As a lower limit of the thickness of a glass substrate, 0.15 mm or more is preferable and 0.25 mm or more is more preferable.

As a glass substrate manufactured by this embodiment, the glass substrate of the following glass compositions is illustrated. That is, the raw material of molten glass is prepared so that the glass substrate of the following glass compositions is manufactured.
<Glass composition>
Examples of the glass composition to which the present embodiment is applied include the following (mass% display).
SiO _2: 50~70% _{(preferably, 57~64%), Al 2 O} 3: 5~25% ( _{preferably, 12~18%), B 2 O} 3: 0~15% ( preferably, 6 ~ 13%), and may optionally contain the following composition. As optional components, MgO: 0 to 10% (preferably 0.5 to 4%), CaO: 0 to 20% (preferably 3 to 7%), SrO: 0 to 20% (preferably, from 0.5 to 8%, more preferably 3~7%), BaO: 0~10% ( preferably 0-3%, more preferably _{0~1%), ZrO 2: 0~10} % ( preferably 0 to 4%, more preferably 0 to 1%). Furthermore, it is more preferable that R ′ ₂ O: more than 0.10% and 2.0% or less (provided that R ′ is at least one selected from Li, Na, and K).
_{Alternatively,} SiO 2: _{50~70% (preferably, 55~65%), B 2 O} 3: 0~10% ( _{preferably, 0~5%, 1.3~5%),} Al 2 O 3: 10-25% (preferably 16-22%), MgO: 0-10% (preferably 0.5-4%), CaO: 0-20% (preferably 2-10%, 2-6 %), SrO: 0 to 20% (preferably 0 to 4%, 0.4 to 3%), BaO: 0 to 15% (preferably 4 to 11%), RO: 5 to 20% (preferably Is preferably 8 to 20%, 14 to 19%) (wherein R is at least one selected from Mg, Ca, Sr and Ba). Furthermore, it is more preferable that R ′ ₂ O contains more than 0.10% and 2.0% or less (provided that R ′ is at least one selected from Li, Na and K).
Furthermore, the following are mentioned as a physical-property value of the glass substrate of this embodiment.
<Young's modulus>
As a Young's modulus of the glass substrate to which this embodiment is applied, for example, 72 (Gpa) or more is preferable, 75 (Gpa) or more is more preferable, and 77 (Gpa) or more is even more preferable.
<Strain point>
As a distortion rate of the glass substrate to which this embodiment is applied, 650 degreeC or more is preferable, for example, 680 degreeC or more is more preferable, 700 degreeC or more and 720 degreeC or more are still more preferable.
Further, for example, the liquid phase viscosity of the glass substrate is 10 ^4.3 poise to 10 ^6.7 poise.
Of course, in the present invention, the glass composition of the glass substrate is not limited.
<Others>
As a method for forming sheet glass from molten glass in this embodiment, a float method, a fusion method, or the like is used. However, a method for manufacturing a glass substrate including offline heat treatment of the glass substrate in this embodiment is a fusion method (overdown). The draw method is suitable for the fusion method because it is difficult to lengthen the slow cooling device on the production line. The thermal contraction rate of the glass substrate before reducing the thermal contraction rate by the heat treatment of this embodiment is 50 ppm or less, preferably 40 ppm or less, more preferably 30 ppm or less, and even more preferably 20 ppm or less. The range of the heat shrinkage rate of the glass substrate before reducing the heat shrinkage rate is preferably 10 ppm to 40 ppm.

  As a method for forming sheet glass from molten glass in this embodiment, a float method, a fusion method, or the like is used. However, a method for manufacturing a glass substrate including offline heat treatment of the glass substrate in this embodiment is a fusion method (overdown). The draw method is suitable for the fusion method because it is difficult to lengthen the slow cooling device on the production line.

(3) Feature “Temperature control of molten glass processing equipment at start of operation”
FIG. 5 is a schematic view of a molten glass processing apparatus heated by the temperature increasing method of the present embodiment in the production of a glass plate. As the processing apparatus, a glass supply pipe 104 (temperature increase control 1) and a fining pipe 102 are used. A processing apparatus including a (temperature increase control 2), a glass supply pipe 105 (temperature increase control 3), a stirring vessel 103 (temperature increase control 4), and a glass supply pipe 106 (temperature increase control 5) is shown.
Hereinafter, a method including a glass supply pipe 104, a clarification pipe 102, a glass supply pipe 105, a stirring tank 103, and a glass supply pipe 106 connected to the melting furnace 101 by a temperature raising method of a molten glass processing apparatus in glass plate manufacturing. A method for raising the temperature of the apparatus will be described.

[Temperature control of glass supply pipe 104]
The temperature increase control of the glass supply pipe 104 will be described.
The melting furnace 101 is provided with a burner and electrodes not shown. When the preparation for starting the operation of the glass plate manufacturing apparatus including the melting furnace is completed, a predetermined amount of glass raw material containing a refining agent is charged into the melting tank 101, and the charged glass raw material is burner heated and energized with a burner flame. Thus, a molten glass MG that is initially introduced into the glass supply pipe 104 (at the start of operation) is produced.

Before the molten glass MG produced in the melting furnace 101 is introduced into the glass supply pipe 104, the glass supply pipe 104 is cooled to a temperature lower than the operating temperature of the glass supply pipe 104 (eg, about 1650 ° C.), for example, about 100 ° C. The temperature is maintained at a standby temperature T ₁ of 200 ° C. lower. To glass supply tube 104 which is maintained at a standby temperature T _1, while introducing molten glass MG made in a melting furnace 101 at a predetermined flowrate (kg / s), temperature of the glass supply tube to operating temperature T ₂ Warming up (temperature rise control 1) (FIG. 3). Standby temperature T ₁ of the processing apparatus of the molten glass, a molten glass temperature Tsurareru in melter 101, the temperature condition of the glass in the supply pipe 104 of the processing unit, operating temperature T _2, can be set on the basis of these.

Regarding the introduction of the molten glass MG from the melting furnace 101 to the glass supply tube 104, the amount of heat (A) brought from the molten glass MG into the glass supply tube 104 and the heat dissipation amount radiated from the entire supply tube unit including the glass supply tube 104. The introduction speed (kg / s) of the molten glass MG having the relationship (B) with (A) <(B) is defined as the introduction reference flow rate X ₀ (kg / s), and the introduction speed is based on the introduction reference flow rate X ₀ . The introduction speed is determined so as not to exceed the introduction reference flow rate X ₀ (kg / s), and the molten glass MG is introduced little by little. By thus regulating the introduction flow rate of the molten glass MG, it is possible to ensure the Atsushi Nobori width of the optimum device for raising the temperature of the glass supply tube 104 from the standby temperature T ₁ of up to operating temperature T ₂ (FIG. 3 and FIG. 4).

When introducing the molten glass MG from the melting furnace 101 to the glass supply pipe 104, the introduction rate of the molten glass MG as described above is not regulated, and the amount of heat brought into the glass supply pipe 104 from the molten glass MG is the glass supply pipe. When the entire supply tube unit containing 104 molten glass in the introduction rate exceeding the heat radiation amount is radiated from (including heat insulating member) (B) is introduced, the glass supply tube 104 is operating in a rapid pace from the standby temperature T ₁ of In some cases, the temperature rises above the temperature T _2, and it becomes impossible to control the temperature of the glass supply pipe 104. In addition, the temperature of the apparatus rises rapidly, and even if the processing apparatus having a higher apparatus temperature than expected exceeding the operating temperature T ₂ is cooled by a cooling function, the apparatus temperature can be controlled. It may take time, or it may be difficult to obtain temperature control to enter a steady state of operation.

(Calculation of introduction reference flow rate _{X 0)}
When introducing molten glass into the glass supply tube 104, to determine the introduction rate based on the introduction reference flow X ₀ (kg / s), a predetermined liquid level position of the glass supply tube 104 (e.g., L ₁ in FIG. 5) Until then, molten glass MG is introduced little by little. By introducing wait temperature T ₁ of molten glass MG into a glass feed tube was maintained at a until a predetermined liquid level position of the glass supply tube 104 filled with molten glass, operating temperature and heated to operating temperature T ₂ is when stabilized , while maintaining the operating temperature T ₂ to wait for the introduction of the molten glass to the next step.

For setting the introduction reference flow X _0, first calculates the heat radiation amount (B). Fluid and structural analysis to calculate the amount of heat release when introducing molten glass MG into the glass supply pipe 104 (heat release amount during introduction time from introduction start to predetermined liquid level position or heat release amount per unit time) Prediction can be calculated using simulation.
Usually, the glass supply pipe 104 is covered with a refractory material or the like, and is provided with a heat retaining structure. As the heat radiation amount when introducing the molten glass MG predetermined temperature in the supply pipe 104 which is heated to the standby temperature T _1, the thermal conductivity of the materials used in the supply pipe 104 and the thermal insulation structure [W / m / K Furthermore, by considering environmental conditions such as the temperature around the glass supply tube unit, the heat release amount (B) that the entire glass supply tube unit radiates to the external space can be calculated by simulation. Alternatively, the heat release amount (B) may be calculated based on the heat release amount data obtained by a small-scale apparatus having a configuration equivalent to the facility specification.

Heat radiation amount between introducing the molten glass MG standby temperature T ₁ of the predetermined temperature to supply pipe 104 which is heated up (B) than, bringing the amount of heat introduced into the glass supply tube 104 from the molten glass MG introduced ( The introduction reference flow rate X ₀ (kg / s) is set so that A) is a small amount of heat. That is, the relationship between the amount of heat (A) brought into the glass supply pipe 104 that is a molten glass processing apparatus and the amount of heat released from the entire supply pipe unit including the glass supply pipe 104 (B) is ( a) <(B) and made as an introduction rate of the molten glass MG is (kg / s) introduced the reference flow _{X 0} is set. The amount of heat (A) brought into the molten glass processing apparatus by the molten glass MG is calculated from the density [kg / m ³ ], the viscosity [Pa · s], and the specific heat [J / kg · K] of the glass.

(Management of the liquid surface position in the introduction by introducing a reference flow X ₀₎
Regarding the flow rate control (control of introduction speed) of the molten glass MG introduced from the melting furnace 101 into the glass supply pipe 104, a plurality of thermometers, liquid level meters, and velocimeters from the vicinity of the inlet of the glass supply pipe 104 to the outlet. , by providing the like, can be controlled by monitoring change (difference) to the introduction reference flow X _0, the introduction of the molten glass MG from the melting furnace 101 (introduction rate). When the introduction flow rate (kg / s) of the molten glass MG approaches the introduction reference flow rate X ₀ , the liquid level of the molten glass MG flowing out to the glass supply pipe is suppressed by suppressing the amount of the glass raw material introduced into the melting furnace 101. May be controlled to adjust the flow rate of the molten glass MG introduced. By appropriately managing the introduction control of the introduction speed of the molten glass MG every predetermined time, the introduction of the molten glass and the temperature increase control of the glass supply pipe 104 can be more stably performed.
A reference position L (L _{1 in} FIG. 5) for waiting for introduction into the next process is set in the glass supply pipe 104 (temperature increase control 1). As described above, the supply pipe 104 is heated while restricting the introduction to the glass supply pipe based on the introduction reference flow rate X ₀ , and when the liquid level is introduced to the reference position L ₁ , the introduction of the molten glass MG is waited and supplied. Continue heating tube 104.

As described above, when introducing molten glass into the supply pipe 104 on the basis of the introduced reference flow X _0, the glass supply tube 104 is slightly from the standby temperature T ₁ of up to operating temperature T ₂ while the flow rate regulating (flow control) The temperature is raised step by step. When the liquid level of the molten glass MG reaches the predetermined liquid level position L ₁ of the glass supply pipe 104, temperature control is ensured so that the operation temperature T ₂ of the glass supply pipe 104 becomes constant, and the glass supply pipe 104 is clarified. Wait until the molten glass MG is introduced into the tube 102.
The process of introducing the molten glass MG from the melting furnace to the supply pipe 104 (temperature increase control) by specifying the same liquid level height position as the liquid level position L ₁ of the glass supply pipe 104 in the previous melting furnace. The end position of 1) can be accurately controlled. Further, by specifying such a reference position (L ₁ ) in the immediately preceding process, it can be used as an introduction control means for the introduction speed of the molten glass (FIG. 5).

  The glass supply tube 104 can be made of platinum or a platinum alloy, or can be made of a material in which metal oxide particles are dispersed in platinum or a platinum alloy. That is, reinforced platinum or reinforced platinum alloy in which metal oxide particles are dispersed in platinum or a platinum alloy can be used for the glass supply tube.

  The glass supply pipe 104 is covered with an alumina cement 114a, and a heat transfer member 114b such as a refractory brick is stacked on the outer side to form a transfer pipe unit 114. That is, a heat retaining structure 114 b is provided around the glass supply tube 104. Further, both end portions 104a and 104b of the glass supply tube 104 have a flange shape and project outside the heat retaining structure 114b. Both end portions 104a and 104b of the present embodiment have a flange shape. However, as long as the both end portions 104a and 104b are cooled from the outside of the pipe, they may not have the flange shape.

[Temperature control 2 to Temperature control 5]
The processing apparatus in this embodiment defoams O ₂ contained in the molten glass MG from the melting furnace in addition to the glass supply pipe 104 that transfers the molten glass MG from the melting furnace to the clarification tube at a predetermined temperature. A clarification tube for refining the molten glass, a stirring vessel for homogenizing the molten glass MG, a glass supply tube 2 for transferring the molten glass from the clarification tube to the stirring vessel at a predetermined temperature, and a predetermined amount from the stirring vessel to the compact. A glass supply pipe 3 for transferring the molten glass MG at a temperature of;
Furthermore, at the start of operation, the molten glass is caused to flow out of the melting furnace, and the molten glass MG is predetermined in order from the glass supply pipe 1 to the refining pipe, the glass supply pipe 2, the stirring tank, and the glass supply pipe 3. when introducing to the reference position, in each of these processing devices, the flow rate of the molten glass on the basis of the respective introduction reference flow X ₀ is regulated, it is heated to the respective operating temperature T ₂ (FIG. 6).

Introduction of molten glass MG from the glass supply tube 104 to the clarification tube 102 (temperature increase control 2), introduction of molten glass MG from the clarification tube 102 to the glass supply tube 105 (temperature increase control 3), and stirring from the glass supply tube 105 The introduction of the molten glass MG to the tank 103 (temperature increase control 4) and the introduction of the molten glass MG from the agitation tank 103 to the glass supply pipe 106 (temperature increase control 5) (FIG. 5) are also described above. Similarly, to identify the heat of the molten glass MG to bring the processor (a) <heat radiation amount (B) and a rate of introduction of molten glass comprising introducing reference flow X _{0 (kg} / s) and, introducing the reference flow X ₀ The temperature of the molten glass processing apparatus is raised while regulating the amount of molten glass introduced based on the above.
Thus, temperature increase control 2, Atsushi Nobori control 3, Atsushi Nobori control 4, also in the Atsushi Nobori control 5, by regulating the introduction flow rate of the molten glass MG, heated from standby temperatures T ₁ until operating temperature T ₂ Therefore, it is possible to secure a temperature increase range of the processing apparatus that is optimal for the above (FIGS. 3 and 4).

In each of the temperature increase control 2, the temperature increase control 3, the temperature increase control 4, and the temperature increase control 5, the introduction rate of the molten glass MG as described above is not regulated to introduce the molten glass MG, and the molten glass MG is not regulated. When the molten glass is introduced at an introduction rate that exceeds the heat dissipation amount (B) radiated from the entire unit including the heat retaining mechanism provided in the processing device, the processing device is set to the standby temperature T _1. rises above the operating temperature T ₂ at a rapid pace from, it may become impossible to raise the temperature control. The temperature of the device rises rapidly, and the temperature of the device can be controlled even if the processing device that has exceeded the operating temperature T _{2 and} has a higher temperature than expected is cooled by the cooling function. It may take time, or it may be difficult to obtain temperature control to enter a steady state of operation.

Atsushi Nobori control 2, Atsushi Nobori control 3, Atsushi Nobori control 4, temperature increase control 5 also in each case to introduce molten glass to the processor, determine the introduction rate (kg / s) based on the introduction reference flow X ₀ and, up to a constant liquid level position of the processing device in a standby temperature T _1, to introduce the molten glass MG gradually. When the molten glass is filled up to a predetermined liquid surface position and heated to the operating temperature T ₂ and the operating temperature is stabilized, introduction of the molten glass to the next process is awaited while maintaining the operating temperature T ₂ .

Atsushi Nobori control 2, Atsushi Nobori control 3, Atsushi Nobori control 4, also in the Atsushi Nobori control 5 respectively, for setting the introduction reference flow X _0, first calculates the heat radiation amount (B). In the same manner as the supply pipe 104, the calculation of the amount of heat released when the molten glass MG is introduced (the amount of heat released during the introduction time from the start of introduction to the predetermined liquid surface position or the amount of heat released per unit time) is also calculated by the fluid and structural analysis. It can be calculated by simulation or the like. The amount of heat (A) brought into the molten glass processing apparatus by the molten glass MG is calculated from the density [kg / m ³ ], the viscosity [Pa · s], and the specific heat [J / kg · K] of the glass.

In each of the temperature increase control 2, the temperature increase control 3, the temperature increase control 4, and the temperature increase control 5, the amount of heat released while the molten glass MG having a predetermined temperature is introduced into the supply pipe 104 heated to the standby temperature T _1. The introduction reference flow rate X ₀ (kg / s) is set so that the amount of heat (A) brought into the glass supply tube 104 from the introduced molten glass MG is smaller than that in (B).

Atsushi Nobori control 2, Atsushi Nobori control 3, Atsushi Nobori control 4, temperature increase control 5 also in each as described above, may comprise a method and means for monitoring changes (difference) to the introduction reference flow X _0, dissolution The introduction amount (introduction speed) of the molten glass MG from the furnace 101 can be controlled. By appropriately managing the introduction control of the introduction speed of the molten glass MG every predetermined time, the introduction of the molten glass and the temperature rise control of the processing apparatus can be more stably performed.

As described above, when introducing molten glass into the supply pipe 104 on the basis of the introduced reference flow X _0, the glass supply tube 104 is slightly from the standby temperature T ₁ of up to operating temperature T ₂ while the flow rate regulating (flow control) The temperature is raised step by step. When the liquid level of the molten glass MG reaches the predetermined liquid level position L ₁ of the glass supply pipe 104, temperature control is ensured so that the operation temperature T ₂ of the glass supply pipe 104 becomes constant, and the glass supply pipe 104 is clarified. Wait until the molten glass MG is introduced into the tube 102.
In each of the temperature rise control 2, the temperature rise control 3, the temperature rise control 4, and the temperature rise control 5 processing devices, as in the supply pipe 104, the reference position for waiting for the start of glass introduction to the next process is specified. Is preferred.

  Similarly to the glass supply pipe 104, the processing devices in the temperature raising control 2, the temperature raising control 3, the temperature raising control 4, and the temperature raising control 5 are also configured using platinum or a platinum alloy, or platinum or a platinum alloy is made of metal. It can be made of a material in which oxide particles are dispersed.

  Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments, and various modifications and changes may be made without departing from the spirit of the present invention. .

As described above, regarding the introduction of the molten glass MG into the processing apparatus for processing the molten glass, in each processing apparatus, the amount of heat (A) brought from the molten glass MG to the processing apparatus and the heat released from the entire processing apparatus unit. The introduction speed (kg / s) of the molten glass MG that has a relationship with the amount of heat (B) where (A) <(B) is taken as the introduction reference flow rate X ₀ (kg / s). It is set based on ₀ , and the molten glass MG is introduced little by little based on the introduction reference flow rate X ₀ (kg / s). By thus regulating the introduction flow rate of the molten glass MG, can each processor to ensure the Atsushi Nobori width of the optimum device for heating from the standby temperature T ₁ of up to operating temperature T ₂ (FIG. 6 ).
In each processing apparatus, the introduction speed of the molten glass is optimally controlled based on the introduction reference flow rate X ₀ (kg / s) at the start of operation. There is no need to take measures such as adjusting the temperature of the apparatus with a cooling function, and an efficient and stable steady state can be reached. Furthermore, since the steady state can be reached smoothly without any abnormality, it is advantageous in that the temperature history of the target molten glass is formed in each processing apparatus, and a glass substrate of good quality can be mass-produced.

101 Melting furnace (melting equipment)
102 clarification tube 103 stirring tank (stirring device)
104 Glass supply pipe 1
105 Glass supply tube 2
106 Glass supply tube 3
200 Molding device 210 Molded body 300 Cutting device

Claims (7)

A melting step of melting glass raw material in a melting furnace to produce molten glass, a molten glass processing step of processing molten glass using a processing apparatus for processing the molten glass made in the melting furnace, and the molten glass processing A glass plate manufacturing method including a forming step of forming a sheet glass by forming a molten glass processed in the step,
At the start of operation, the molten glass from the melting furnace is introduced into the processing apparatus, and the processing apparatus is heated to maintain the processing apparatus at a standby temperature T ₁ lower than the operating temperature T _2. Assuming that the introduction rate of molten glass at which the amount of heat (A) brought into the processing apparatus and the heat dissipation amount (B) of the processing apparatus is (A) <(B) is the introduction reference flow rate X ₀ (kg / s), molten glass When the glass plate is introduced, the flow rate of the molten glass is regulated every predetermined time based on the introduction reference flow rate X ₀ , and the processing apparatus is heated to the operating temperature T _2. Method. The processing apparatus includes: a refining tube for defoaming O ₂ contained in the molten glass from the melting furnace to clarify the molten glass; a stirring tank for homogenizing the molten glass; and the melting furnace to the refining tube. A glass supply pipe 1 for transferring the molten glass at a predetermined temperature, a glass supply pipe 2 for transferring the molten glass from the clarification pipe to the stirring tank at a predetermined temperature, and melting from the stirring tank to the molded body at the predetermined temperature. A glass supply pipe 3 for transferring glass,
At the start of operation, the molten glass is caused to flow out of the melting furnace, and the molten glass is sequentially supplied to the glass supply pipe 1, the refining pipe, the glass supply pipe 2, the stirring tank, and the glass supply pipe 3 in order. when introducing to a position, in each of the processing apparatus, the flow rate of the molten glass on the basis of each of the introduction reference flow X ₀ is regulated, is heated to the respective operating temperature T _2, according to claim 1 Manufacturing method of glass plate. The treatment the introduction of the molten glass in the apparatus, the introduced reference flow X ₀ and not as being flow restriction than is heated until said operating temperature T _2, the manufacture of glass plate according to claim 1 or 2 Method.   The said processing apparatus is a manufacturing method of the glass plate as described in any one of Claim 1 to 3 which thermally radiates the amount of method heat (B), without being accompanied by cooling. A melting furnace for melting glass raw material to produce molten glass;
A processing device provided with heating means, for introducing and processing the molten glass;
A molding apparatus for forming a sheet glass by molding the molten glass processed by the processing apparatus,
At start operations, the molten glass from the melting furnace is introduced into the processing apparatus, to heat the apparatus, maintaining said processing apparatus at operating temperature T ₂ lower standby temperatures T ₁ than the molten glass Is the introduction reference flow rate X ₀ (kg / s), the amount of heat introduced into the processing apparatus (A) and the heat dissipation amount (B) of the processing apparatus is (A) <(B). when introducing the molten glass, every predetermined time, the introduction reference flow X ₀ to regulate the flow rate of the molten glass on the basis of said processing apparatus is heated to operating temperature T ₂ by the heating means, that A glass plate manufacturing apparatus. The processing apparatus includes: a refining tube for defoaming O ₂ contained in the molten glass to clarify the molten glass; a stirring tank for homogenizing the molten glass; and the molten glass from the melting furnace to the refining tube at a predetermined temperature. A glass supply pipe 1 for transferring at a predetermined temperature, a glass supply pipe 2 for transferring molten glass from the clarification pipe to the stirring tank at a predetermined temperature, and a glass supply for transferring molten glass from the stirring tank to the molded body at a predetermined temperature. A tube 3;
At the start of the operation, the molten glass is caused to flow out of the melting furnace, and the molten glass is supplied to the glass supply pipe 1, the clarification pipe, the glass supply pipe 2, the stirring tank, and the glass supply pipe 3 in order. when introducing to the reference position, each processing device is the flow rate of the molten glass on the basis of each of the introduction reference flow X ₀ is regulated, it is heated to the respective operating temperature T _2, according to claim 5 Glass plate manufacturing equipment. The processing unit, when introducing the molten glass, so as not to exceed the introduction reference flow X _0, comprising a regulating means for the flow rate of the molten glass is regulated, is heated to a year operating temperature T _2, wherein Item 7. An apparatus for producing a glass plate according to Item 5 or 6.