Glass article manufacturing method and glass article manufacturing device

Abstract

To transfer a good quality molten glass from a melting furnace to a molding part of a glass article by sufficiently heating a molten glass in the periphery of a sidewall inside the melting furnace.SOLUTION: A method for manufacturing a glass article includes a melting step of heating and melting a glass raw material Ga with an electrode 3 disposed in a bottom wall 1a of a melting furnace 1 and acquiring a molten glass Gm. The electrode 3 is disposed so as to flow part of a current energized by the electrode 3 through a sidewall 1b of the melting furnace 1.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for producing a glass article from molten glass produced in a melting furnace, and more particularly to an improvement in technology for heating and melting glass raw materials in a melting furnace to obtain molten glass. [Background technology]

[0002] As is well known, a method for manufacturing glass articles such as glass fibers and glass plates includes a melting step of heating and melting glass raw materials in a melting furnace.

[0003] In this melting step, it is known that the molten glass is heated and melted by applying an electric current to the molten glass using electrodes arranged on the bottom wall of the melting furnace, thereby obtaining molten glass (see Patent Documents 1 and 2).

[0004] The molten glass obtained in the melting step flows out of the melting furnace into a transfer channel leading to a glass article forming section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-183031 [Patent Document 2] Japanese Patent Application Publication No. 2019-34871 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the method of disposing electrodes on the bottom wall of the melting furnace as disclosed in Patent Documents 1 and 2, heat inside the melting furnace is dissipated to the outside of the furnace through the side walls. If no measures are taken to address this, a temperature drop occurs around the side walls of the melting furnace, making it difficult to properly heat the molten glass. In this case, glass raw materials that are not sufficiently heated and melted may flow out of the melting furnace into the transfer flow path, which may hinder the supply of high-quality molten glass. Furthermore, the viscosity of the molten glass may increase around the side walls of the melting furnace, forming a stagnant layer. If the molten glass in the stagnant layer flows out of the melting furnace into the transfer flow path, bubbles and striae may occur in the resulting glass product. This may also hinder the supply of high-quality molten glass.

[0007] In view of the above, an object of the present invention is to enable the molten glass to be sufficiently heated around the side walls of the melting furnace, and to transport high-quality molten glass from the melting furnace toward a glass article forming section. [Means for solving the problem]

[0008] A first aspect of the present invention, which has been invented to solve the above-mentioned problems, is a method for manufacturing a glass article, which includes a melting step in which glass raw materials are heated and melted using electrodes arranged on the bottom wall of a melting furnace to obtain molten glass, and is characterized in that the electrodes are arranged so that a part of the current passed through the electrodes flows on a side wall of the melting furnace.

[0009] With this configuration, a portion of the current applied by the electrodes flows to the side wall of the melting furnace, heating the side wall, thereby reducing the temperature drop of the molten glass around the side wall in the melting furnace. This allows the molten glass to be sufficiently heated around the side wall, making it possible to transport high-quality molten glass from the melting furnace toward the forming section of the glass article.

[0010] In this configuration, it is preferable to apply a current to the side wall so that the maximum value of the heat generation per unit area at the side wall is 20% or more and 150% or less of the heat radiation amount from the side wall.

[0011] Here, if the maximum value of the heat generation per unit area on the side wall is 20% or more of the heat radiation from the side wall, the temperature drop of the molten glass around the side wall in the melting furnace can be reliably reduced. On the other hand, if the maximum value of the heat generation per unit area on the side wall is 150% or less of the heat radiation from the side wall, damage to the side wall due to heat can be reduced. Here, the maximum value of the heat generation per unit area on the side wall is calculated using [Equation 5] and [Equation 7] described below. Furthermore, the heat radiation from the side wall is measured using, for example, a heat flow meter (HFM-201 manufactured by Kyoto Electronics Manufacturing Co., Ltd.) and a heat flow sensor (T750S-B manufactured by Kyoto Electronics Manufacturing Co., Ltd.).

[0012] In the above configuration, the electrodes are preferably arranged such that a pair of electrodes between which a current flows is aligned in a direction along the inner wall surface of the side wall closest to the electrode, and multiple pairs of the electrodes are aligned in a direction intersecting the inner wall surface of the side wall.

[0013] In this way, the electrodes are arranged in a manner that allows current to flow efficiently through the side walls.

[0014] In this configuration, it is preferable that the ratio (Lx / L) of the distance Lx from the electrode closest to the inner wall surface of the side wall to the distance L between the pair of electrodes is 3.0 or less.

[0015] Here, if the ratio of the distances is 3.0 or less, the electrode closest to the inner wall surface of the side wall is close to the inner wall surface of the side wall, and a sufficient current can be passed through the side wall.

[0016] In the above configuration, the electrodes may be arranged so as to satisfy the following formula (1).

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[0017] In this way, a specific electrode arrangement can be obtained that makes the maximum heat generation per unit area on the side wall 20% or more of the heat dissipation from the side wall (details are explained in the "Form for implementing the invention" section).

[0018] Furthermore, the electrodes may be arranged so as to satisfy the following formula (2).

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[0019] In this way, a specific electrode arrangement can be obtained that makes the maximum heat generation per unit area on the side wall 50% or more of the heat dissipation from the side wall (details are explained in the "Form for implementing the invention" section).

[0020] In addition, the electrodes may be arranged so as to satisfy the following formula (3).

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[0021] In this way, a specific electrode arrangement can be obtained that keeps the maximum heat generation per unit area on the side wall at 150% or less of the heat dissipation from the side wall (details are explained in the "Form for implementing the invention" section).

[0022] In the above configuration, it is preferable that the ratio (R2 / R1) of the resistivity R2 of the molten glass at a predetermined heating temperature to the resistivity R1 of the firebricks constituting the side wall at the predetermined heating temperature is 1 or more.

[0023] In this way, a sufficient amount of current can be passed through the side wall, thereby preventing insufficient heat generation in the side wall and enabling more appropriate heating of the molten glass around the side wall.

[0024] In the above configuration, the molten glass may be E-glass and the refractory bricks constituting the side walls may be chrome bricks, where E-glass refers to the composition defined in ASTM D578-05 4.2.2.

[0025] In this way, the ratio (R2 / R1) becomes 1 or more, and a sufficient amount of current can be passed through the side wall, thereby preventing insufficient heat generation in the side wall and making it possible to more appropriately heat the molten glass around the side wall. Furthermore, in glass fiber manufacturing methods, E glass is often used as the molten glass, and the side wall of the melting furnace is often made of chrome bricks. Therefore, the molten glass and the melting furnace having the side wall can be effectively used, particularly in glass fiber manufacturing methods.

[0026] A second aspect of the present invention, which has been invented to solve the above-mentioned problems, is an apparatus for manufacturing a glass article, which includes a melting furnace that heats and melts glass raw materials using electrodes arranged on a bottom wall to produce molten glass, and is characterized in that the electrodes are arranged so that a portion of the current passed through the electrodes flows to a side wall of the melting furnace.

[0027] This makes it possible to enjoy the same effects as the previously described manufacturing method having substantially the same configuration as this manufacturing apparatus. [Effects of the Invention]

[0028] According to the present invention, the molten glass can be sufficiently heated around the side walls in the melting furnace, and good quality molten glass can be transported from the melting furnace toward the forming section of the glass article. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a vertical cross-sectional side view illustrating a schematic configuration of a main part of a glass article manufacturing apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic plan view showing the arrangement of electrodes around the side wall of a melting furnace, which is a component of a glass article manufacturing apparatus according to an embodiment of the present invention. [Figure 3] 1 is a graph showing a first simulation result relating to a method for manufacturing a glass article according to an embodiment of the present invention. [Figure 4] 10 is a graph showing second simulation results relating to the method for manufacturing a glass article according to an embodiment of the present invention. [Figure 5] 10 is a graph showing a simulation result in an example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, a method and an apparatus for manufacturing a glass article according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0031] FIG. 1 is a longitudinal sectional side view illustrating the schematic configuration of the main components of a glass article manufacturing apparatus according to this embodiment. As shown in the figure, a melting furnace 1 included in this manufacturing apparatus melts glass raw material (solid raw material) Ga by heating, including electrical heating, to produce molten glass Gm. In this melting furnace 1, a melting space is defined by a bottom wall 1a and a side wall 1b made of firebricks. The upper part of the melting space is covered by a ceiling wall 1c. The molten glass Gm produced in the melting space flows out of an outlet 1d of the melting furnace 1 into a transfer flow path 2 and is transported through the transfer flow path 2 toward a glass article forming unit (not shown). In this embodiment, the glass article forming unit is a bushing that forms glass fibers.

[0032] Examples of the molten glass Gm transferred toward the bushing include E-glass (glass with an alkali content of 2% or less), D-glass (low dielectric constant glass), AR-glass (alkali-resistant glass), C-glass (acid-resistant glass), M-glass (high modulus glass), S-glass (high strength, high modulus glass), T-glass (high strength, high modulus glass), H-glass (high dielectric constant glass), and NE-glass (low dielectric constant glass). The density of the glass is, for example, 2.0 to 3.0 g / cm. 3 is.

[0033] A plurality of electrodes 3 for electrically heating the molten glass Gm are arranged on the bottom wall 1a of the melting furnace 1. These electrodes 3 penetrate the bottom wall 1a, protrude upward, and are immersed in the molten glass Gm. In this embodiment, the lower limit of the upward protrusion length d of these electrodes 3 from the bottom wall 1a is, for example, 20% or more, preferably 30% or more, and more preferably 40% or more of the depth D of the molten glass Gm. Furthermore, the upper limit of the protrusion length d is, for example, 80% or less, preferably 70% or less, and more preferably 60% or less of the depth D of the molten glass Gm. Furthermore, in this embodiment, a system is adopted in which electrical heating by these electrodes 3 and gas combustion heating by a burner are used in combination, but gas combustion heating by a burner may be omitted.

[0034] A screw feeder 4, which is a raw material supply device, is disposed on the upper part of the side wall 1b of the melting furnace 1. This screw feeder 4 sequentially supplies glass raw material Ga to a part of the liquid surface Gma of the molten glass Gm. Note that instead of the screw feeder 4, other raw material supply devices such as a pusher or a vibration feeder may be used.

[0035] In the manufacturing method according to this embodiment, a melting step is carried out by the manufacturing apparatus having the above-described configuration, in which glass raw material Ga is heated and melted using electrodes 3 arranged on the bottom wall 1a of the melting furnace 1 to obtain molten glass Gm.

[0036] FIG. 2 is a cross-sectional plan view showing the arrangement of electrodes 3 relative to side wall 1b. Side wall 1b has a quadrangular (preferably rectangular) shape in plan view and thus has four faces. However, for convenience, only side wall 1b corresponding to one face is shown in FIG. 2. As shown in FIG. 2, electrodes 3 are arranged such that a pair of electrodes 3, between which a current flows, is aligned along the inner wall surface 1z of side wall 1b closest to electrode 3, and multiple pairs of electrodes 3 (two pairs in the illustrated example) are aligned in a direction intersecting with inner wall surface 1z of side wall 1b. Voltages (e.g., single-phase AC voltages) are applied between first electrode 3a and second electrode 3b and between third electrode 3c and fourth electrode 3d. Accordingly, currents flow between first electrode 3a and second electrode 3b and between third electrode 3c and fourth electrode 3d.

[0037] The direction along inner wall surface 1z is preferably a direction parallel to inner wall surface 1z, but may also be a direction inclined at an angle of 10° or less to one side or the other side with respect to this parallel direction. Furthermore, the direction intersecting inner wall surface 1z is preferably a direction perpendicular to inner wall surface 1z, but may also be a direction inclined at an angle of 10° or less to one side or the other side with respect to this perpendicular direction.

[0038] The characteristic configuration and effects of the method for manufacturing a glass article according to this embodiment will be described below.

[0039] The first characteristic feature is that the electrodes 3 are arranged so that a portion of the current flowing between the electrodes 3 flows to the side wall 1b. This allows the current to flow through the side wall 1b, which in turn heats the side wall 1b. In this case, a temperature drop of the molten glass Gm tends to occur around the side wall 1b in the melting furnace 1, but heating the side wall 1b reduces this temperature drop. This allows the molten glass Gm to be sufficiently heated around the side wall 1b, making it possible to produce high-quality molten glass Gm in the melting furnace 1. This allows high-quality molten glass Gm to be transported through the transport flow path 2 toward the bushing.

[0040] The second characteristic configuration is that, under the above-described arrangement of electrodes 3, a current flows through side wall 1b so that the maximum value of the heat generated per unit area at side wall 1b is 20% or more and 150% or less of the heat dissipation amount from side wall 1b. In this case, if the maximum value of the heat generated per unit area at side wall 1b is less than 20% of the heat dissipation amount from side wall 1b, it is difficult to sufficiently reduce the temperature drop of molten glass Gm around side wall 1b. On the other hand, if the maximum value of the heat generated per unit area at side wall 1b is more than 150% of the heat dissipation amount from side wall 1b, side wall 1b may be damaged by heat. In contrast, if the numerical range is 20% or more and 150% or less as described above, the temperature drop of molten glass Gm around side wall 1b can be reliably reduced and damage to side wall 1b due to heat can be prevented.

[0041] The third characteristic configuration is that the ratio (Lx / L) of 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 (hereinafter referred to as the shortest distance Lx from the electrode 3 to the side wall 1b) is 3.0 or less to the distance L between the pair of electrodes 3. 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, and a sufficient current can flow through the side wall 1b.

[0042] A fourth characteristic configuration is that the ratio (R2 / R1) of the resistivity R2 of the molten glass Gm at a predetermined heating temperature to the resistivity R1 of the refractory bricks constituting the side wall 1b at the predetermined heating temperature is preferably not less than 1, and more preferably not less than 2. In this case, a sufficient amount of current can be passed through the side wall 1b, thereby eliminating insufficient heat generation in the side wall 1b and making it possible to more appropriately heat the molten glass Gm around the side wall 1b.

[0043] Next, a simulation carried out by the present inventors will be described with reference to Fig. 2. This simulation was carried out to confirm the heat generation effect when a current is passed through the side wall 1b.

[0044] The specific conditions for the simulation were: glass depth D = 1 m; spacing p = 0.5 m between the three pairs of electrodes in the direction intersecting the inner wall surface 1z of the side wall 1b; protrusion length d = 0.5 m of the electrodes 3 from the bottom wall 1a; and thickness t = 0.15 m of the side wall 1b. The simulation was conducted under four conditions: distance L = 1 m, 1.33 m, 1.66 m, and 2 m between the pair of electrodes 3 in the direction along the inner wall surface 1z of the side wall 1b. The simulation was also conducted under three conditions: ratio A (Lx / L) of the shortest distance Lx from the electrode 3 to the distance L between the pair of electrodes 3 = 0.5, 1.0, and 2.0. Furthermore, the simulation was conducted under two conditions: ratio B (R2 / R1) of the resistivity R2 of the molten glass Gm to the resistivity R1 of the side wall 1b = 4 and 8. Here, the resistivity ratio B is the ratio when the side wall 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 electroformed bricks, or the molten glass Gm may be made of a glass other than E-glass among the above-listed glasses. Taking this into consideration, it is preferable that the resistivity ratio B is 1 or more, as described above.

[0045] FIG. 3 shows the average heat generation density ω of the molten glass Gm when the resistivity ratio B is set to 4. ave Maximum heat generation density ω of side wall 1b max The ratio C(ω max / ω ave ) is shown in a graph. ave Maximum heat generation density ω of side wall 1b max The ratio C(ω max / ω ave ) is a graph showing the average heat density ω of the molten glass Gm. ave is the average value of the heat generation per unit volume of the molten glass Gm. Also, the maximum heat generation density ω max is the maximum value of the heat generation per unit volume of the side wall 1b. Figures 3 and 4 plot data obtained for a total of 12 types of data obtained by changing the 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 distance L between the electrodes 3.

[0046] The inventors noticed from Figures 3 and 4 that the ratio C changes exponentially with respect to the ratio A, and calculated the curve S from the simulation results (the plotted data) by the least squares method. The curve S shown in Figure 3 and the curve S shown in Figure 4 are the same. Therefore, the curve S was calculated from a total of 24 types of simulation results. The curve S is expressed by the following formula [4].

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[0047] Average heat density ω of molten glass Gm ave is expressed by the following equation [5].

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[0048] Maximum heat density ω of side wall 1b max is expressed by the following [Equation 6], which is a modification of the above [Equation 4].

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[0049] Furthermore, the maximum heat generation density ωmax By multiplying this by the thickness t of the side wall 1b, the maximum value of the heat generation per unit area of ​​the side wall 1b, ω max Therefore, the following equation (7) holds true:

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[0050] In order to obtain a heating effect on the side wall 1b, the maximum value of the heat generation amount per unit area on the side wall 1b, ω max It is preferable to heat the side wall 1b at a rate of t equal to or greater than 20% of the heat radiation amount W from the side wall 1b (for the reasons already explained). To achieve this, the following formula [8] must be satisfied. The above formula [1] is obtained by substituting the above formula [5] into the following formula [8] and then modifying it.

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[0051] In order to obtain a further heating effect on the side wall 1b, the maximum value ω of the heat generation amount per unit area on the side wall 1b is max It is preferable to heat the side wall 1b at a rate of 50% or more of the heat radiation amount W from the side wall 1b. To achieve this, the following formula [9] must be satisfied. Note that the above-mentioned formula [2] is obtained by substituting the above formula [5] into the following formula [9] and modifying it.

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[0052] On the other hand, excessive heating of the side wall 1b may cause the refractory bricks constituting the side wall 1b to melt and be damaged. maxAs t becomes larger than the amount of heat radiation W from the side wall 1b, the refractory bricks tend to melt and become damaged. In order to prevent excessive heat generation from the side wall 1b, the maximum value ω of the amount of heat generated per unit area of ​​the side wall 1b is max It is necessary to ensure that t does not greatly exceed the amount of heat radiation W from the side wall 1b. Taking this into consideration, the maximum value of the amount of heat generated per unit area on the side wall 1b, ω max It is preferable that t is 1.5 times or less the heat radiation amount W from the side wall 1b. For this to happen, the following formula (10) must be satisfied. Note that the above formula (3) is obtained by substituting the above formula (5) into the following formula (10) and modifying it.

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[0053] The above describes the glass article manufacturing method and manufacturing apparatus according to an embodiment of the present invention, but the present invention is not limited to this, and various variations are possible within the scope of the gist of the present invention.

[0054] For example, in the above embodiment, the arrangement of the electrodes 3 was described for only the side wall 1b corresponding to one surface of the melting furnace 1. However, the same arrangement of the electrodes 3 may also be applied to the side wall opposite the side wall 1b, or to the side walls 1b corresponding to the other three surfaces of the side wall 1b. When the side wall 1b has a rectangular shape in plan view as in the above embodiment, it is preferable to apply the arrangement to both the side wall 1b located between the side wall 1b where the raw material supply device (screw feeder 4) is disposed and the side wall 1b where the outlet 1d is disposed. If the side wall 1b located between the side wall 1b where the raw material supply device (screw feeder 4) is disposed and the side wall 1b where the outlet 1d is disposed is longer than the length of the side wall 1b in plan view, a wider area of ​​the side wall 1b can be heated.

[0055] In the above embodiment, an example has been given of a pair of electrodes 3 arranged in a direction along the inner wall surface 1z of the side wall 1b, with two pairs arranged in a direction intersecting the inner wall surface 1z of the side wall 1b, but three or more pairs may also be arranged in a direction intersecting the inner wall surface 1z of the side wall 1b.

[0056] In the above embodiment, the present invention is applied to a method and apparatus for manufacturing glass fibers, but the present invention may also be applied to a method and apparatus for manufacturing glass articles other than glass fibers (for example, glass plates, glass tubes, etc.). [Example]

[0057] An example of the present invention will be described below. In this example, multiple pairs of electrodes were arranged in a direction along the inner wall surface 1z of the side wall 1b of the melting furnace 1, and in a direction intersecting (perpendicular to) the inner wall surface 1z of the side wall 1b. The depth D of the molten glass Gm in the melting furnace 1 was 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 was 1.5 m, the spacing p between the pair of electrodes 3 in the direction intersecting the inner wall surface 1z of the melting furnace 1 was 0.5 m, the protrusion length d of the electrodes 3 from the bottom wall 1a was 0.5 m, and the thickness t of the side wall 1b was 0.15 m. 100 kW of power was supplied to each pair of electrodes 3. Therefore, the average heat generation density ω of the molten glass Gm in this example was 1. ave is 133.3kW / m from equation [5]. 3 The ratio B (R2 / R1) of the resistivity R2 of the molten glass to the resistivity R1 of the side wall 1b was set to 6. The amount of heat radiation W from the side wall 1b can be measured using, for example, a heat flow meter (HFM-201 manufactured by Kyoto Electronics Manufacturing Co., Ltd.) and a heat flow sensor (T750S-B manufactured by Kyoto Electronics Manufacturing Co., Ltd.), and here it was set to 2000 W / m 2 It was decided.

[0058] Under the above conditions, in order to make the maximum value of the heat generation amount per unit area of ​​the side wall 1b 20% or more of the heat radiation amount W from the side wall 1b, the maximum heat generation density ω of the side wall 1b can be calculated from the formula [8]. max to 2.7kW / m 3 Accordingly, from 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.

[0059] Furthermore, in order to make the maximum value of the heat generation amount per unit area on the side wall 1b 50% or more of the heat radiation amount W from the side wall 1b, the maximum heat generation density ω maxto 6.7kW / m 3 Accordingly, from equation (2), the ratio A needs to be 1.47 or less.

[0060] On the other hand, in order to prevent excessive heating of the side wall 1b, in order to make the maximum heat generation amount per unit area of ​​the side wall 1b 1.5 times or less than the heat radiation amount W from the side wall 1b, the maximum heat generation density ω max to 20kW / m 3 Accordingly, from equation (3), the ratio A needs to be 0.97 or more.

[0061] Based on this theory, simulations were carried out for ratios A of 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0, and the maximum heat generation density ω max The results are shown in Fig. 5. The curve S1 shown in Fig. 5 represents the equation [6]. The above simulation results will be discussed below with reference to Fig. 5.

[0062] When considering equation (1), the simulation results show that when the ratio A is set to 2.0 (greater than 1.89 as mentioned above), the maximum heat generation density ω max is 2.3kW / m 3 This corresponds to 20% of the heat dissipation amount W, which is 2.7 kW / m 3 On the other hand, in the simulation results when the ratio A is set to 1.8 (less than 1.89 as mentioned above), the maximum heat generation density ω max is 3.3kW / m 3 This corresponds to 20% of the heat dissipation amount W, which is 2.7 kW / m 3 From the simulation results, it can be seen that there is a boundary between when the ratio A is between 2.0 and 1.8, at which point the maximum heat generation amount per unit area of ​​the side wall 1b exceeds 20% of the heat radiation amount W from the side wall 1b. This confirms that the formula (1) is appropriate.

[0063] When considering equation 2, the simulation results show that when the ratio A is set to 1.6 (greater than 1.47 as mentioned above), the maximum heat generation density is 4.8 kW / m 3 This corresponds to 50% of the heat dissipation amount W, which is 6.7 kW / m 3 On the other hand, in the simulation results when the ratio A is set to 1.4 (less than 1.47 as mentioned above), the maximum heat generation density ω max is 7.2kW / m 3 This corresponds to 50% of the heat dissipation amount W, which is 6.7 kW / m 3 From the simulation results, it can be seen that there is a boundary between when the ratio A is between 1.6 and 1.4, at which the maximum heat generation amount per unit area of ​​the side wall 1b exceeds 50% of the heat radiation amount W from the side wall 1b. This confirms that the formula (2) is appropriate.

[0064] When considering equation 3, the simulation results show that when the ratio A is set to 1.0 (above 0.97), the maximum heat generation density is 16.9 kW / m 3 This corresponds to 150% of the heat dissipation amount W, and is 20 kW / m 3 On the other hand, in the simulation results when the ratio A is set to 0.8 (less than 0.97 as mentioned above), the maximum heat generation density ω max is 27.4kW / m 3 This corresponds to 150% of the heat dissipation amount W, and is 20 kW / m 3 From the simulation results, it can be seen that there is a boundary between the ratio A of 1.0 and 0.8 at which the maximum heat generation per unit area of ​​the side wall 1b exceeds 150% of the heat radiation amount W from the side wall 1b. This confirmed that the formula (3) is appropriate. [Explanation of symbols]

[0065] 1 melting furnace 1a Bottom wall 1b side wall 1z Inner surface of side wall 3 electrodes 3a First electrode 3b Second electrode 3c Third electrode 3d fourth electrode Ga ガラス raw materials Gm melting ガラス

Claims

1. A method for manufacturing a glass article, comprising a melting step of heating and melting glass raw materials using electrodes arranged on a bottom wall of a melting furnace to obtain molten glass, The electrode is arranged so that a portion of the current passed through the electrode flows to a side wall of the melting furnace; A method for manufacturing a glass article, comprising: passing an electric current through the side wall so that the maximum heat generation amount per unit area of ​​the side wall is 20% or more and 150% or less of the heat radiation amount from the side wall.

2. 2. The method for manufacturing a glass article according to claim 1, wherein the electrodes are arranged such that a pair of electrodes between which a current flows is aligned in a direction along the inner wall surface of the side wall closest to the pair of electrodes, and multiple pairs of the electrodes are aligned in a direction intersecting the inner wall surface of the side wall.

3. A method for manufacturing a glass article, comprising a melting step of heating and melting glass raw materials using electrodes arranged on the bottom wall of a melting furnace to obtain molten glass, The electrode is arranged so that a portion of the current passed through the electrode flows to a side wall of the melting furnace; The electrodes are arranged such that a pair of electrodes between which a current flows is aligned in a direction along the inner wall surface of the side wall closest to the pair of electrodes, and a plurality of pairs of the electrodes are aligned in a direction intersecting the inner wall surface of the side wall, A method for manufacturing a glass article, characterized in that the electrodes are arranged so as to satisfy the following formula (1): [Equation 1] where: A is a ratio (Lx / L) of a distance Lx from an electrode closest to the inner wall surface of the side wall to the distance L between the pair of electrodes, and 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 pair in a direction perpendicular to the inner wall surface of the side wall, L is the distance (m) between the pair of electrodes, t is the thickness of the side wall (m), W is the amount of heat dissipated from the side wall (W / m 2 ).

4. A method for manufacturing a glass article, comprising a melting step of heating and melting glass raw materials using electrodes arranged on the bottom wall of a melting furnace to obtain molten glass, The electrode is arranged so that a portion of the current passed through the electrode flows to a side wall of the melting furnace; The electrodes are arranged such that a pair of electrodes between which a current flows is aligned in a direction along the inner wall surface of the side wall closest to the pair of electrodes, and a plurality of pairs of the electrodes are aligned in a direction intersecting the inner wall surface of the side wall, A method for manufacturing a glass article, characterized in that the electrodes are arranged so as to satisfy the following formula (2): [Equation 2] where: A is a ratio (Lx / L) of a distance Lx from an electrode closest to the inner wall surface of the side wall to the distance L between the pair of electrodes, and 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 pair in a direction perpendicular to the inner wall surface of the side wall, L is the distance (m) between the pair of electrodes, t is the thickness of the side wall (m), W is the amount of heat dissipated from the side wall (W / m 2 ).

5. A method for manufacturing a glass article, comprising a melting step of heating and melting glass raw materials using electrodes arranged on the bottom wall of a melting furnace to obtain molten glass, The electrode is arranged so that a portion of the current passed through the electrode flows to a side wall of the melting furnace; The electrodes are arranged such that a pair of electrodes between which a current flows is aligned in a direction along the inner wall surface of the side wall closest to the pair of electrodes, and a plurality of pairs of the electrodes are aligned in a direction intersecting the inner wall surface of the side wall, A method for manufacturing a glass article, characterized in that the electrodes are arranged so as to satisfy the following formula (3): [Equation 3] where: A is a ratio (Lx / L) of a distance Lx from an electrode closest to the inner wall surface of the side wall to the distance L between the pair of electrodes, and 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 pair in a direction perpendicular to the inner wall surface of the side wall, L is the distance (m) between the pair of electrodes, t is the thickness of the side wall (m), W is the amount of heat dissipated from the side wall (W / m 2 ).

6. The method for manufacturing a glass article according to any one of claims 2 to 5, wherein a ratio (Lx / L) of a distance Lx from an electrode closest to the inner wall surface of the side wall to a distance L between the pair of electrodes is 3.0 or less.

7. The method for manufacturing a glass article according to any one of claims 3 to 5, wherein an electric current is passed through the side wall so that the maximum value of the heat generation amount per unit area in the side wall is 20% or more and 150% or less of the heat radiation amount from the side wall.

8. 8. The method for manufacturing a glass article according to any one of claims 1 to 7, wherein a ratio (R2 / R1) of a resistivity R2 of molten glass at a predetermined heating temperature to a resistivity R1 of the refractory bricks constituting the side wall at the predetermined heating temperature is 1 or more.

9. 9. The method for manufacturing a glass article according to claim 1, wherein the molten glass is E-glass and the refractory bricks constituting the side walls are chrome bricks.

10. An apparatus for manufacturing a glass article, comprising a melting furnace for heating and melting glass raw materials using electrodes arranged on a bottom wall to produce molten glass, The electrodes are arranged so that a portion of the current passed through the electrodes flows to a side wall of the melting furnace; A glass article manufacturing apparatus characterized in that it is configured to pass an electric current through the side wall so that the maximum heat generation amount per unit area at the side wall is 20% or more and 150% or less of the heat radiation amount from the side wall.

11. An apparatus for manufacturing a glass article, comprising a melting furnace for heating and melting glass raw materials using electrodes arranged on a bottom wall to produce molten glass, The electrodes are arranged so that a portion of the current passed through the electrodes flows to a side wall of the melting furnace; The electrodes are arranged such that a pair of electrodes between which a current flows is aligned in a direction along the inner wall surface of the side wall closest to the pair of electrodes, and a plurality of pairs of the electrodes are aligned in a direction intersecting the inner wall surface of the side wall, A glass article manufacturing apparatus characterized in that the electrodes are arranged so as to satisfy the following formula (1): [Equation 1] where: A is a ratio (Lx / L) of a distance Lx from an electrode closest to the inner wall surface of the side wall to the distance L between the pair of electrodes, and 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 pair in a direction perpendicular to the inner wall surface of the side wall, L is the distance (m) between the pair of electrodes, t is the thickness of the side wall (m), W is the amount of heat dissipated from the side wall (W / m 2 ).

12. An apparatus for manufacturing a glass article, comprising a melting furnace for heating and melting glass raw materials using electrodes arranged on a bottom wall to produce molten glass, The electrodes are arranged so that a portion of the current passed through the electrodes flows to a side wall of the melting furnace; The electrodes are arranged such that a pair of electrodes between which a current flows is aligned in a direction along the inner wall surface of the side wall closest to the pair of electrodes, and a plurality of pairs of the electrodes are aligned in a direction intersecting the inner wall surface of the side wall, A glass article manufacturing apparatus characterized in that the electrodes are arranged so as to satisfy the following formula (2): [Equation 2] where: A is a ratio (Lx / L) of a distance Lx from an electrode closest to the inner wall surface of the side wall to the distance L between the pair of electrodes, and 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 pair in a direction perpendicular to the inner wall surface of the side wall, L is the distance (m) between the pair of electrodes, t is the thickness of the side wall (m), W is the amount of heat dissipated from the side wall (W / m 2 ).

13. An apparatus for manufacturing a glass article, comprising a melting furnace for heating and melting glass raw materials using electrodes arranged on a bottom wall to produce molten glass, The electrodes are arranged so that a portion of the current passed through the electrodes flows to a side wall of the melting furnace; The electrodes are arranged such that a pair of electrodes between which a current flows is aligned in a direction along the inner wall surface of the side wall closest to the pair of electrodes, and a plurality of pairs of the electrodes are aligned in a direction intersecting the inner wall surface of the side wall, A glass article manufacturing apparatus characterized in that the electrodes are arranged so as to satisfy the following formula (3): [Equation 3] where: A is a ratio (Lx / L) of a distance Lx from an electrode closest to the inner wall surface of the side wall to the distance L between the pair of electrodes, and 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 pair in a direction perpendicular to the inner wall surface of the side wall, L is the distance (m) between the pair of electrodes, t is the thickness of the side wall (m), W is the amount of heat dissipated from the side wall (W / m 2 ).

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