WO2023120155A1

WO2023120155A1 - Method for manufacturing glass article, and device for manufacturing glass article

Info

Publication number: WO2023120155A1
Application number: PCT/JP2022/044867
Authority: WO
Inventors: 信吾鈴木; 孝介愛内
Original assignee: 日本電気硝子株式会社
Priority date: 2021-12-20
Filing date: 2022-12-06
Publication date: 2023-06-29
Also published as: JP2023091397A

Abstract

This method for manufacturing a glass article involves a melting step for heating and melting a glass raw material Ga using an electrode 3 disposed on a bottom wall 1a of a melting furnace 1 to obtain melted glass Gm, wherein the electrode 3 is disposed such that part of current distributed by the electrode 3 flows to a side wall 1b of the melting furnace 1.

Description

Glass article manufacturing method and glass article manufacturing apparatus

The present invention relates to a method and apparatus for producing glass articles from molten glass produced in a melting furnace, and particularly to improvements in technology for heating and melting frit in a melting furnace to obtain molten glass.

As is well known, the method of manufacturing glass articles such as glass fibers and glass plates includes a melting process of heating and melting glass raw materials in a melting furnace.

In this melting step, it is known to obtain molten glass by heating and melting the frit by heating the molten glass using electrodes arranged on the bottom wall of the melting furnace (Patent Document 1, 2).

The molten glass obtained in the melting process flows out from the melting furnace into the transfer channel leading to the molding section of the glass article.

Japanese Patent Application Laid-Open No. 2003-183031 JP 2019-34871 A

By the way, in the method of arranging the electrodes on the bottom wall of the melting furnace as disclosed in

Patent Documents

1 and 2, the heat inside the melting furnace is radiated out of the furnace through the side wall. If no measures are taken against this, a temperature drop will occur around the side walls in the melting furnace, making it difficult to properly heat the molten glass. In this case, frit that has not been sufficiently heated and melted may flow out of the melting furnace into the transfer flow path, thereby interfering with the supply of good quality molten glass. In addition, when the viscosity of the molten glass rises around the side wall in the melting furnace to form a stagnant layer, and the molten glass in the stagnant layer flows out of the melting furnace into the transfer channel, bubbles and striae are formed in the resulting glass article. It may occur. This may also hinder the supply of good quality molten glass.

In view of the above, an object of the present invention is to enable the molten glass to be sufficiently heated around the side wall in the melting furnace, and to transfer the good quality molten glass from the melting furnace to the molding portion of the glass article. be.

A first aspect of the present invention, which has been devised to solve the above problems, is a glass article having a melting step for obtaining molten glass by heating and melting frit using electrodes arranged on the bottom wall of a melting furnace. characterized in that the electrodes are positioned such that a portion of the current conducted by the electrodes flows to the side walls of the melting furnace.

According to such a configuration, part of the current supplied by the electrodes flows through the side walls of the melting furnace, thereby heating the side walls, so that the temperature drop of the molten glass around the side walls in the melting furnace can be reduced. . Therefore, the molten glass can be sufficiently heated around the side walls, and good quality molten glass can be transferred from the melting furnace toward the molding portion of the glass article.

In this configuration, it is preferable to apply current to the side wall so that the maximum amount of heat generated per unit area at the side wall is 20% or more and 150% or less of the amount of heat released from the side wall.

Here, if the maximum value of the amount of heat generated per unit area on the side wall is 20% or more of the amount of heat released from the side wall, it is possible to reliably reduce the temperature drop of the molten glass around the side wall in the melting furnace. On the other hand, if the maximum amount of heat generated per unit area at the side wall is 150% or less of the amount of heat released from the side wall, it is possible to reduce thermal damage to the side wall. Here, the maximum value of the amount of heat generated per unit area on the sidewall is calculated by [Equation 5] and [Equation 7] described later. The amount of heat radiation from the side walls is measured using, for example, a heat flow meter (HFM-201 manufactured by Kyoto Electronics Industry Co., Ltd.) and a heat flow sensor (T750S-B manufactured by Kyoto Electronics Industry Co., Ltd.).

In the above configuration, the electrodes are arranged such that a pair of electrodes through which current flows between them is arranged in a direction along the inner wall surface of the side wall closest to the electrodes, and the pair of electrodes is arranged along the inner wall surface of the side wall. It is preferable that a plurality of pairs are arranged in a direction intersecting with.

By doing so, the mode of arranging the electrodes becomes a mode in which the current can be efficiently passed through the side wall.

In this configuration, it is preferable that the ratio of the distance Lx from the electrode closest to the inner wall surface of the side wall to the inner wall surface of the side wall to the distance L between the pair of electrodes (Lx/L) is 3.0 or less. .

Here, if the above distance ratio is 3.0 or less, the electrode closest to the inner wall surface of the side wall will be close to the inner wall surface of the side wall, allowing a sufficient current to flow through the side wall.

In the above configuration, the electrodes may be arranged so as to satisfy the following [Equation 1].

here,
A is the ratio of the distance Lx from the electrode closest to the inner wall surface of the side wall to the inner wall surface of the side wall to the distance L between the pair of electrodes (Lx/L);
Q is the power (W) supplied to the pair of electrodes;
D is the depth (m) of the molten glass in the melting furnace;
p is the distance (m) between the electrode pairs in the direction orthogonal to the inner wall surface of the side wall;
L is the distance (m) between the pair of electrodes,
t is the thickness (m) of the sidewall,
W is the heat radiation amount (W/m ² ) from the side walls.

In this way, it is possible to obtain a specific electrode arrangement mode for making the maximum amount of heat generated per unit area on the side wall 20% or more of the amount of heat released from the side wall (for details, refer to [Invention [Mode for implementation] column).

Furthermore, the electrodes may be arranged so as to satisfy the following [Equation 2].

Here, the meanings of A, Q, D, p, L, t, and W are the same as those in the above formula (1).

In this way, it is possible to obtain a specific electrode arrangement mode for making the maximum amount of heat generated per unit area on the side wall 50% or more of the amount of heat released from the side wall (details are described in [Invention [Mode for implementation] column).

In addition, the electrodes may be arranged so as to satisfy the following [Equation 3].

In this way, it is possible to obtain a specific electrode arrangement mode for making the maximum amount of heat generated per unit area on the side wall 150% or less of the amount of heat released from the side wall (for details, refer to the [Invention [Mode for implementation] column).

In the above configuration, the ratio (R2/R1) of the specific resistance R2 of the molten glass at the predetermined heating temperature to the specific resistance R1 of the refractory bricks forming the side wall at the predetermined heating temperature is preferably 1 or more. .

In this way, a sufficient amount of current can be passed through the side wall, so that insufficient heat generation of the side wall can be eliminated and the molten glass can be heated more appropriately around the side wall.

In the above configuration, the molten glass may be E-glass, and the firebricks forming the side walls may be chrome bricks. E-glass means a composition defined by ASTM D578-05 4.2.2.

In this way, the above-mentioned ratio (R2/R1) becomes 1 or more, and a sufficient amount of current can be passed through the side wall, so that insufficient heat generation of the side wall is eliminated and the molten glass is heated around the side wall. can be performed more appropriately. Further, in the method of producing glass fibers, E-glass is often used as the molten glass, and the side walls of the melting furnace are often made of chrome bricks. Therefore, the molten glass here and the melting furnace with side walls here can be effectively used, in particular, in a method for producing glass fibers.

A second aspect of the present invention, which has been devised to solve the above problems, is the manufacture of a glass article equipped with a melting furnace that heats and melts glass raw materials using electrodes arranged on the bottom wall to produce molten glass. An apparatus, characterized in that the electrodes are arranged such that part of the current conducted by the electrodes flows in the side walls of the melting furnace.

According to this, it is possible to enjoy the same effect as the above-described manufacturing method having substantially the same configuration as this manufacturing apparatus.

According to the present invention, it becomes possible to sufficiently heat the molten glass around the side wall in the melting furnace, and it becomes possible to transfer the good quality molten glass from the melting furnace toward the molding portion of the glass article.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal side view which illustrates schematic structure of the principal part in the manufacturing apparatus of the glass article which concerns on embodiment of this invention. 1 is a schematic plan view showing an arrangement of electrodes around a side wall of a melting furnace, which is a component of the apparatus for manufacturing glass articles according to an embodiment of the present invention; FIG. It is a graph which shows the 1st simulation result regarding the manufacturing method of the glass article which concerns on embodiment of this invention. It is a graph which shows the 2nd simulation result regarding the manufacturing method of the glass article which concerns on embodiment of this invention. It is a graph which shows the simulation result in the Example of this invention.

A method and apparatus for manufacturing a glass article according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a vertical cross-sectional side view illustrating the schematic configuration of the main part of the glass article manufacturing apparatus according to the present embodiment. As shown in the figure, a melting furnace 1 provided in this manufacturing apparatus melts frit (solid raw material) Ga by heating including electric heating to generate molten glass Gm. This melting furnace 1 has a melting space defined by a bottom wall 1a and a side wall 1b made of refractory bricks. The upper part of the melting space is covered with the ceiling wall 1c. Molten glass Gm produced in the melting space flows out from the outlet 1d of the melting furnace 1 into the transfer channel 2, and is transferred through the transfer channel 2 toward the molding portion (not shown) of the glass article. In this embodiment, the molding portion of the glass article is a bushing that molds the glass fibers.

Examples of the molten glass Gm transferred toward the bushing include E glass (glass having an alkali content of 2% or less), D glass (low dielectric constant glass), AR glass (alkali resistant glass), C glass (acid resistant glass), glass), M glass (high elastic modulus glass), S glass (high strength, high elastic modulus glass), T glass (high strength, high elastic modulus glass), H glass (high dielectric constant glass), NE glass (low dielectric constant glass) can be mentioned. The density of glass is, for example, 2.0-3.0 g/cm ³ .

A plurality of electrodes 3 are arranged on the bottom wall 1a of the melting furnace 1 for electrically heating the molten glass Gm. These electrodes 3 protrude upward through the bottom wall 1a and are immersed in the molten glass Gm. In the present embodiment, the lower limit of the projection length d upward from the bottom wall 1a of these electrodes 3 is, for example, 20% or more, preferably 30% or more, more preferably 40% or more of the depth D of the molten glass Gm. It is said that Further, the upper limit of the projection length d is, for example, 80% or less, preferably 70% or less, more preferably 60% or less of the depth D of the molten glass Gm. In addition, in this embodiment, a method is adopted in which electric heating by these electrodes 3 and gas combustion heating by a burner are used together, but a method in which gas combustion heating by a burner is omitted may be used.

A screw feeder 4 as a raw material feeder is arranged on the upper part of the side wall 1b of the melting furnace 1. This screw feeder 4 sequentially supplies frit Ga to a portion of the liquid surface Gma of the molten glass Gm. In addition, instead of the screw feeder 4, other raw material feeders such as a pusher and a vibrating feeder may be used.

In the manufacturing method according to the present embodiment, the manufacturing apparatus having the above configuration heats and melts the frit Ga using the electrode 3 arranged on the bottom wall 1a of the melting furnace 1 to obtain the molten glass Gm. A melting process is performed.

FIG. 2 is a cross-sectional plan view showing how the electrodes 3 are arranged with respect to the side wall 1b. Since the side wall 1b has a square shape (preferably a rectangular shape) in a plan view, it has four faces, but for the sake of convenience, only the side wall 1b corresponding to one face is shown in the figure. . As shown in the figure, the electrodes 3 are arranged such that a pair of electrodes 3 through which current flows between them are arranged in a direction along the inner wall surface 1z of the side wall 1b closest to the electrodes 3. A plurality of pairs (two pairs in the figure) are arranged in a direction intersecting the inner wall surface 1z of 1b. A voltage (for example, a single-phase AC voltage) is applied between the first electrode 3a and the second electrode 3b and between the third electrode 3c and the fourth electrode 3d. Accordingly, current flows between the first electrode 3a and the second electrode 3b and between the third electrode 3c and the fourth electrode 3d.

The direction along the inner wall surface 1z is preferably a direction parallel to the inner wall surface 1z, but a direction inclined within 10° to one side or within 10° to the other side with respect to the parallel direction. There may be. In addition, the direction intersecting the inner wall surface 1z is preferably a direction perpendicular to the inner wall surface 1z. may be

Hereinafter, the characteristic configuration of the method for manufacturing a glass article according to the present embodiment and the effects thereof will be described.

The first characteristic configuration is that the electrodes 3 are arranged so that part of the current flowing between the electrodes 3 flows through the sidewall 1b. According to this, the side wall 1b is heated by the current flowing through the side wall 1b. In this case, the temperature of the molten glass Gm tends to drop around the side wall 1b in the melting furnace 1, but the temperature drop is reduced by heating the side wall 1b. Thereby, the molten glass Gm can be sufficiently heated around the side wall 1b, and the molten glass Gm of good quality can be produced in the melting furnace 1. Therefore, it becomes possible to transfer the molten glass Gm of good quality toward the bushing through the transfer channel 2 .

A second characteristic configuration is that under the arrangement of the electrodes 3 as described above, the maximum amount of heat generated per unit area on the sidewall 1b is 20% or more and 150% or less of the amount of heat released from the sidewall 1b. The difference is that the current flows through the side wall 1b so that In this case, if the maximum amount of heat generated per unit area at the side wall 1b is less than 20% of the amount of heat released from the side wall 1b, the temperature drop of the molten glass Gm around the side wall 1b should be sufficiently reduced. is difficult. On the other hand, if the maximum amount of heat generated per unit area at the side walls 1b exceeds 150% of the amount of heat released from the side walls 1b, the side walls 1b may be thermally damaged. On the other hand, if the numerical range is 20% or more and 150% or less as described above, the temperature drop of the molten glass Gm around the side wall 1b is reliably reduced, and the heat of the side wall 1b Damage etc. can be prevented.

The third characteristic configuration is the distance Lx from the electrode 3 (first electrode 3a and second electrode 3b) closest to the inner wall surface 1z of the side wall 1b to the inner wall surface 1z of the side wall 1b with respect to the distance L between the pair of electrodes 3. The difference is that the ratio (Lx/L) of (hereinafter referred to as the shortest distance Lx from the electrode 3 to the side wall 1b) is 3.0 or less. If the ratio (Lx/L) is 3.0 or less, the first electrode 3a and the second electrode 3b are close to the inner wall surface 1z of the side wall 1b, allowing sufficient current to flow through the side wall 1b.

The fourth characteristic configuration is that the ratio (R2/R1) of the specific resistance R2 of the molten glass Gm at the predetermined heating temperature to the specific resistance R1 of the refractory bricks constituting the side wall 1b at the predetermined heating temperature is preferably 1 As described above, it is more preferable that the number is 2 or more. In this case, a sufficient amount of current can be passed through the side wall 1b, so that insufficient heat generation of the side wall 1b can be eliminated, and the molten glass Gm can be heated more appropriately around the side wall 1b. Become.

Next, the simulation performed by the inventors will be described with reference to FIG. This simulation was performed to confirm the heat generation effect when a current is passed through the side wall 1b.

The specific conditions under which the simulation was performed were as follows: the glass depth D was 1 m; The thickness d was set to 0.5 m, and the thickness t of the side wall 1b was set to 0.15 m. Then, four conditions of 1 m, 1.33 m, 1.66 m, and 2 m for the distance L between the pair of electrodes 3 in the direction along the inner wall surface 1z of the side wall 1b were tested. Moreover, the ratio A (Lx/L) of the shortest distance Lx from the electrode 3 to the side wall 1b to the distance L between the pair of electrodes 3 was carried out under three conditions of 0.5, 1.0, and 2.0. Furthermore, the ratio B (R2/R1) of the specific resistance R2 of the molten glass Gm to the specific resistance R1 of the side wall 1b was measured under two conditions of 4 and 8. Here, the specific resistance ratio B is the ratio when the sidewall 1b is made of chrome bricks and E glass is used as the molten glass Gm. In this case, the side wall 1b may be made of a refractory material other than chrome bricks, such as an electroformed brick, or a glass other than the E glass listed above may be used as the molten glass Gm. Considering this, the ratio B of the resistivity is preferably 1 or more as described above.

FIG. 3 is a graph showing the ratio C (ω _max /ω _ave ) of the maximum heat generation density ω _max of the sidewall 1b to the average heat generation density ω _ave of the molten glass Gm when the specific resistance ratio B is 4. be. FIG. 4 is a graph showing the ratio C (ω _max /ω _ave ) of the maximum heat generation density ω _max of the sidewall 1b to the average heat generation density ω _ave of the molten glass Gm when the specific resistance ratio B is 8. be. The average calorific value ω _ave of the molten glass Gm is the average value of the calorific value per unit volume of the molten glass Gm. Further, the maximum heat generation density ω _max of the side wall 1b is the maximum value of the heat generation amount per unit volume of the side wall 1b. 3 and 4 show numerical values for the four conditions of the distance L between the electrodes 3 and the three conditions of the ratio A of the shortest distance Lx from the electrode 3 to the side wall 1b to the distance L between the electrodes 3. Data obtained for a total of 12 types are plotted.

From FIGS. 3 and 4, the present inventors focused on the fact that the ratio C changed exponentially with respect to the ratio A, and from the simulation results (the above plotted data), the curve S I figured out. Curve S shown in FIG. 3 and curve S shown in FIG. 4 are the same. Therefore, the curve S is calculated from a total of 24 types of simulation results. This curve S is represented by the following [Equation 4].

here,
ω _max is the maximum heat generation density (W/m ³ ) of the sidewall 1b,
ω _ave is the average heat generation density (W/m ³ ) of the molten glass Gm,
A is the ratio of the shortest distance Lx from the electrode 3 to the side wall 1b to the distance L between the pair of electrodes 3;

The average heat generation density ω _ave of the molten glass Gm is represented by the following [Equation 5].

here,
Q is the power (W) supplied to the pair of electrodes 3,
D is the depth (m) of the molten glass Gm in the melting furnace 1;
p is the interval (m) between the three pairs of electrodes in the direction intersecting the inner wall surface 1z of the side wall 1b,
L is the distance (m) between the pair of electrodes 3 in the direction along the sidewall 1b.

The maximum heat generation density ω _max of the side wall 1b is represented by the following [Equation 6], which is a modification of the above [Equation 4].

Furthermore, by multiplying the maximum heat generation density ω _max of the side wall 1b by the thickness t of the side wall 1b, it is possible to convert the maximum heat generation amount ω _max ·t per unit area of the side wall 1b. Therefore, the following [Equation 7] formula holds.

In order to obtain the heating effect at the side wall 1b, the maximum value ω _max ·t of the heat generation amount per unit area at the side wall 1b must be 20% or more of the heat dissipation amount W from the side wall 1b. is preferably heated (for reasons already mentioned). For that purpose, the following [Equation 8] formula needs to hold. It should be noted that the above-mentioned [Equation 1] is a modified one obtained by substituting the above [Equation 5] into the following [Equation 8].

here,
W is the heat radiation amount (W/m ² ) from the side wall 1b,
t is the thickness (m) of the side wall 1b.

In order to further obtain the heating effect on the side wall 1b, the side wall 1b should be formed such that the maximum value ω _max ·t of the heat generation amount per unit area of the side wall 1b is 50% or more of the heat radiation amount W from the side wall 1b. Heating is preferred. For that purpose, the following [Equation 9] formula must be established. It should be noted that the above-described [Equation 2] is a modified one obtained by substituting the above [Equation 5] into the following [Equation 9].

On the other hand, excessive heating of the side wall 1b causes erosion of the refractory bricks forming the side wall 1b. As the maximum value ω _max ·t of the amount of heat generated per unit area at the side wall 1b becomes larger than the amount W of heat radiation from the side wall 1b, the refractory bricks are likely to be damaged by melting. In order to prevent the side wall 1b from generating excessive heat, it is necessary to prevent the maximum value ω _max ·t of the amount of heat generated per unit area in the side wall 1b from exceeding the heat release amount W from the side wall 1b. . Taking this into consideration, it is preferable that the maximum value ω _max ·t of the amount of heat generated per unit area at the side walls 1b is 1.5 times or less the amount W of heat dissipation from the side walls 1b. For that purpose, the following [Equation 10] formula must be established. It should be noted that the above-described [Equation 3] is a modified one obtained by substituting the above [Equation 5] into the following [Equation 10].

Although the manufacturing method and manufacturing apparatus for glass articles according to the embodiments of the present invention have been described above, the present invention is not limited to this, and various variations are possible without departing from the spirit of the present invention.

For example, in the above-described embodiment, the arrangement of the electrodes 3 was described with respect to only the side wall 1b corresponding to one surface of the melting furnace 1. The side wall 1b corresponding to the surface may also be subject to the same arrangement mode of the electrodes 3. FIG. When the side wall 1b has a square shape in plan view as in the above embodiment, the side wall 1b is positioned between the side wall 1b on which the raw material feeder (screw feeder 4) is arranged and the side wall 1b on which the outflow port 1d is arranged. It is preferable to target both side walls 1b. When the side wall 1b located between the side wall 1b on which the raw material feeder (screw feeder 4) is arranged and the side wall 1b on which the outflow port 1d is arranged are longer than the side wall 1b in plan view, Side wall 1b can be heated over a wide range.

In the above embodiment, the pair of electrodes 3 arranged in the direction along the inner wall surface 1z of the side wall 1b is exemplified in the case where two pairs are arranged in the direction intersecting the inner wall surface 1z of the side wall 1b. Three or more pairs may be arranged in the crossing direction.

In the above embodiments, the present invention is applied to the method and apparatus for producing glass fibers, but the present invention can also be applied to the method and apparatus for producing glass articles other than glass fibers (for example, glass plates and glass tubes). good too.

Examples of the present invention will be described below. In this embodiment, a plurality of pairs of electrodes are arranged along the inner wall surface 1z of the side wall 1b of the melting furnace 1 in a direction intersecting (perpendicular to) the inner wall surface 1z of the side wall 1b. Then, the depth D of the molten glass Gm in the melting furnace 1 is 1 m, the distance L between the pair of electrodes 3 in the direction along the inner wall surface 1z of the melting furnace 1 is 1.5 m, and the inner wall surface 1z of the melting furnace 1 The distance p between the three pairs of electrodes in the intersecting direction was 0.5 m, the projection length d of the electrode 3 from the bottom wall 1a was 0.5 m, and the thickness t of the side wall 1b was 0.15 m. A power of 100 kW was supplied to the electrodes 3 per pair. Therefore, the average heat generation density ω _ave of the molten glass Gm in this example is 133.3 kW/m ³ according to the formula [Equation 5]. Also, the ratio B (R2/R1) of the specific resistance R2 of the molten glass to the specific resistance R1 of the side wall 1b was set to 6. The amount of heat dissipation W from the side wall 1b can be measured using, for example, a heat flow meter (HFM-201 manufactured by Kyoto Electronics Industry Co., Ltd.) and a heat flow sensor (T750S-B manufactured by Kyoto Electronics Industry Co., Ltd.). ^m2 .

Under the above conditions, in order to make the maximum amount of heat generated per unit area at the side wall 1b 20% or more of the amount W of heat radiation from the side wall 1b, the maximum heat generation density of the side wall 1b is obtained from the equation [Equation 8]. ω _max must be 2.7 kW/m ³ or more. Along with this, according to the formula [Equation 1], the ratio A of the shortest distance Lx from the electrode 3 to the side wall 1b to the distance L between the pair of electrodes 3 must be 1.89 or less.

Furthermore, in order to make the maximum amount of heat generated per unit area at the side wall 1b 50% or more of the amount W of heat radiation from the side wall 1b, the maximum heat generation density ω _max of the side wall 1b is set to 6.5 from the formula [Equation 9]. It is necessary to make it 7 kW/m ³ or more. Along with this, it is necessary to set the ratio A to 1.47 or less according to the formula [Equation 2].

On the other hand, for the purpose of avoiding excessive heating of the side wall 1b, in order to make the maximum value of the heat generation amount per unit area of the side wall 1b 1.5 times or less of the heat dissipation amount W from the side wall 1b, [number 10], it is necessary to set the maximum heat generation density ω _max of the sidewall 1b to 20 kW/m ³ or less. Along with this, it is necessary to set the ratio A to 0.97 or more according to the formula [Equation 3].

Under such a theory, simulations were performed with the ratio A set to 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0 Then, the maximum heat generation density ω _max at the side wall was obtained. FIG. 5 shows the results. A curve S1 shown in FIG. 5 represents the expression [6]. The above simulation results are discussed below with reference to FIG.

Examining the formula [Equation 1], the simulation result when the ratio A is set to 2.0 (above 1.89) shows that the maximum heat generation density ω _max is 2.3 kW / m ³ , and the heat dissipation amount W It is less than the above-mentioned 2.7 kW/m ³ which corresponds to 20%. On the other hand, in the simulation results when the ratio A is set to 1.8 (1.89 or less as described above), the maximum heat generation density ω _max is ^3.3 kW/m It is greater than 2.7 kW/m ³ . From the simulation results here, the maximum value of the amount of heat generated per unit area on the sidewall 1b exceeds 20% of the amount of heat dissipation W from the sidewall 1b while the ratio A is from 2.0 to 1.8. It can be understood that there is a boundary between whether or not From this fact, it was confirmed that the formula [Equation 1] is appropriate.

Examining the formula [Equation 2], the simulation results when the ratio A is set to 1.6 (above 1.47) show that the maximum heat generation density is 4.8 kW / m ³ , which is 50% of the heat dissipation amount W is smaller than the above-mentioned 6.7 kW/m ³ corresponding to . On the other hand, the simulation results when ^the ratio A is set to 1.4 (1.47 or less as described above) show that the maximum heat generation density ω _max is 7.2 kW/m It is greater than 6.7 kW/m ³ . From the simulation results here, the maximum value of the amount of heat generated per unit area on the side wall 1b exceeds 50% of the amount W of heat dissipation from the side wall 1b while the ratio A is from 1.6 to 1.4. It can be understood that there is a boundary between whether or not From this fact, it was confirmed that the formula [Equation 2] is appropriate.

Considering the formula [Equation 3], the simulation result when the ratio A is 1.0 (0.97 or more as described above) shows that the maximum heat generation density is 16.9 kW / m ³ , which is 150% of the heat dissipation amount W is smaller than the above-mentioned 20 kW/m ³ corresponding to . On the other hand, the simulation results when the ratio A is set to 0.8 (less than 0.97 as described above) show that the maximum heat generation density ω _max is 27.4 kW/m ³ , which corresponds to 150% of the heat dissipation amount W. greater than 20 kW/m ³ . From the simulation results here, the maximum value of the amount of heat generated per unit area on the side wall 1b exceeds 150% of the amount of heat dissipation W from the side wall 1b while the ratio A is from 1.0 to 0.8. It can be understood that there is a boundary between whether or not From this fact, it was confirmed that the formula [Equation 3] is appropriate.

1 Melting Furnace 1a Bottom Wall 1b Side Wall 1z Side Wall Inner Wall 3 Electrode

3a First Electrode

3b Second Electrode

3c Third Electrode 3d Fourth Electrode Ga Frit Gm Molten Glass

Claims

A method for producing a glass article comprising a melting step of obtaining molten glass by heating and melting glass raw materials using electrodes arranged on the bottom wall of a melting furnace,
A method for producing a glass article, characterized in that the electrodes are arranged such that a portion of the current conducted by the electrodes flows to the side walls of the melting furnace.
2. The method for manufacturing a glass article according to claim 1, wherein current is passed through the sidewalls so that the maximum amount of heat generated per unit area at the sidewalls is 20% or more and 150% or less of the amount of heat released from the sidewalls. .
A mode of arranging the electrodes is such that the pair of electrodes through which current flows between them is arranged in the direction along the inner wall surface of the side wall closest to the electrodes, and the pair of electrodes is arranged in the direction intersecting the inner wall surface of the side wall. 3. The apparatus for manufacturing a glass article according to claim 1 or 2, wherein a plurality of pairs are arranged side by side.
4. The glass according to claim 3, wherein the ratio of the distance Lx from the electrode closest to the inner wall surface of the side wall to the inner wall surface of the side wall to the distance L between the pair of electrodes (Lx/L) is 3.0 or less. Equipment for manufacturing goods.
5. The method for producing a glass article according to claim 3 or 4, wherein the electrodes are arranged so as to satisfy the following [Equation 1].

here,
A is the ratio of the distance Lx from the electrode closest to the inner wall surface of the side wall to the inner wall surface of the side wall to the distance L between the pair of electrodes (Lx/L);
Q is the power (W) supplied to the pair of electrodes;
D is the depth (m) of the molten glass in the melting furnace;
p is the distance (m) between the electrode pairs in the direction orthogonal to the inner wall surface of the side wall;
L is the distance (m) between the pair of electrodes,
t is the thickness (m) of the sidewall,
W is the heat radiation amount (W/m 2 ) from the side walls.
5. The method for manufacturing a glass article according to claim 3 or 4, wherein the electrodes are arranged so as to satisfy the following [Equation 2].

here,
A is the ratio of the distance Lx from the electrode closest to the inner wall surface of the side wall to the inner wall surface of the side wall to the distance L between the pair of electrodes (Lx/L);
Q is the power (W) supplied to the pair of electrodes;
D is the depth (m) of the molten glass in the melting furnace;
p is the distance (m) between the electrode pairs in the direction orthogonal to the inner wall surface of the side wall;
L is the distance (m) between the pair of electrodes,
t is the thickness (m) of the sidewall,
W is the heat radiation amount (W/m 2 ) from the side walls.
5. The method for manufacturing a glass article according to claim 3 or 4, wherein the electrodes are arranged so as to satisfy the following [Equation 3].

here,
A is the ratio of the distance Lx from the electrode closest to the inner wall surface of the side wall to the inner wall surface of the side wall to the distance L between the pair of electrodes (Lx/L);
Q is the power (W) supplied to the pair of electrodes;
D is the depth (m) of the molten glass in the melting furnace;
p is the distance (m) between the electrode pairs in the direction orthogonal to the inner wall surface of the side wall;
L is the distance (m) between the pair of electrodes,
t is the thickness (m) of the sidewall,
W is the heat radiation amount (W/m 2 ) from the side walls.
The ratio (R2/R1) of the specific resistance R2 of the molten glass at the predetermined heating temperature to the specific resistance R1 of the refractory bricks forming the side wall at the predetermined heating temperature is 1 or more. A method for producing the glass article according to 1.
The method for producing a glass article according to any one of claims 1 to 8, wherein the molten glass is E-glass and the firebricks forming the side walls are chromium bricks.
An apparatus for manufacturing a glass article comprising a melting furnace that heats and melts frit to produce molten glass using electrodes arranged on a bottom wall,
An apparatus for manufacturing glass articles, wherein the electrodes are arranged so that part of the current supplied by the electrodes flows to the side wall of the melting furnace.