Glass melting furnace and glass article manufacturing method

Abstract

A glass melting furnace 1 comprises: four first single-phase AC power sources 5; four second single-phase AC power sources 6 that have phases different from those of the first single-phase AC power sources 5; a first electrode group 8 that is formed of eight first electrodes 7 arranged on a bottom wall 1a in a 4-row by 2-column matrix; and a second electrode group 10 that is formed of eight second electrodes 9 arranged on the bottom wall 1a in a 4-row by 2-column matrix at positions different but adjacent to the first electrode group 8. Two terminals o, u that form a pair in each of the first single-phase AC power sources 5 are included in different columns in the first electrode group 8, and are connected to two of the first electrodes 7 arranged at two of the every other positions in the column direction Y. Two terminals о', v that form a pair in each of the second single-phase AC power sources 6 are included in different columns in the second electrode group 10, and are connected to two of the second electrodes 9 arranged at two of the every other positions in the column direction Y.

Description

Glass melting furnace and method for manufacturing glass articles

[0001] The present invention relates to a glass melting furnace and a method for manufacturing glass articles using the same.

[0002] The method for manufacturing glass articles includes a melting step for obtaining molten glass. In the melting step, the molten glass may be heated by energization heating using electrodes provided on the bottom wall of the glass melting furnace. In this case, in order to obtain high-quality glass articles, in order to prevent the outflow of undissolved glass raw materials in the melting step, it is necessary to increase the number of electrodes arranged on the bottom wall of the melting furnace and heat and dissolve the glass raw materials evenly throughout the glass melting furnace.

[0003] Therefore, for example, in Patent Document 1, in order to heat and dissolve the glass raw materials evenly throughout the glass melting furnace, it is necessary to arrange 16 electrodes in a matrix (lattice) of at least 4 rows × 4 columns on the bottom wall of the glass melting furnace. It is disclosed that each of the 16 electrodes arranged in a 4-row × 4-column matrix is supplied with power using 4 first single-phase AC power sources and 4 second single-phase AC power sources having a phase difference from the first single-phase AC power sources.

[0004] Further, the same document discloses that depending on the positional relationship between two electrodes (first electrode pair) to which two terminals forming a pair of the first single-phase AC power source are connected and two electrodes (second electrode pair) to which two terminals forming a pair of the second single-phase AC power source are connected, there is a problem of power factor reduction. Specifically, it is disclosed that among the first electrode pair and the second electrode pair, currents with different phases supplied to one electrode pair flow into the other electrode pair through the molten glass and wiring, and an unintended phase difference occurs between the currents and voltages used for energization heating between the first electrode pair and / or between the second electrode pair, resulting in a reduction in the power factor.

[0005] Japanese Patent Application Laid-Open No. 2024-84397

[0006] In Patent Document 1, the electrode connection with the highest power factor is shown in Figure 7 (corresponding to Figure 12(a) in the same document). In the figure, 101 is the side wall of the glass melting furnace, 102 is the first single-phase AC power supply, 103 is the second single-phase AC power supply, o and u are the terminals of the first single-phase AC power supply (first electrode pair), and o' and v are the terminals of the second single-phase AC power supply (second electrode pair). The wiring of the first single-phase AC power supply 102 is shown with solid lines, and the wiring of the second single-phase AC power supply 103 is shown with dotted lines.

[0007] In the electrode connection shown in Figure 7, while the decrease in power factor can be suppressed, it is difficult to bring the molten glass closer to the desired temperature distribution by adjusting the power distribution of each electrode pair. Specifically, this electrode connection is asymmetric with respect to the flow direction of the glass melting furnace and the width direction perpendicular to the flow direction. Therefore, if one attempts to relatively increase the power of electrode pairs in certain regions, such as the upstream side of the glass melting furnace, in order to bring the molten glass closer to the desired temperature distribution, unintended asymmetric convection may occur in the molten glass. Such asymmetric convection can be a factor that hinders bringing the molten glass closer to the desired temperature distribution.

[0008] The present invention aims to provide a glass melting furnace that heats molten glass by applying an electric current, which allows for easy adjustment of the temperature distribution of molten glass while suppressing a decrease in the power factor.

[0009] (1) The present invention, devised to solve the above problems, is a glass melting furnace for electrically heating molten glass, comprising: four first single-phase AC power supplies; four second single-phase AC power supplies having a phase difference with the first single-phase AC power supplies; a first electrode group consisting of eight first electrodes arranged in a 4x2 matrix on the bottom wall of the glass melting furnace; and a second electrode group consisting of eight second electrodes arranged in a 4x2 matrix on the bottom wall of the glass melting furnace at a different position adjacent to the first electrode group, wherein the two terminals of each first single-phase AC power supply are included in different rows of the first electrode group and are connected to two first electrodes located at positions skipping one in the row direction, and the two terminals of each second single-phase AC power supply are included in different rows of the second electrode group and are connected to two second electrodes located at positions skipping one in the row direction.

[0010] In this configuration, the first electrode group and the second electrode group are positioned at different locations on the bottom wall of the glass melting furnace. By adjusting the power supply to the first and / or second electrode groups, the temperature of the molten glass at different locations corresponding to each electrode group can be individually adjusted. Furthermore, with the above electrode connection, the electrode connection in the first electrode group and the electrode connection in the second electrode group are substantially symmetrical. Therefore, even if the power supply to one electrode group is relatively increased, asymmetrical convection in the molten glass is less likely to occur, and the temperature distribution of the molten glass can be easily adjusted. Moreover, with the above electrode connection, the distance between at least one of the two first electrodes (referred to as the first electrode pair) connected to the two terminals forming a pair of the first single-phase AC power supply and at least one of the two second electrodes (referred to as the second electrode pair) connected to the two terminals forming a pair of the second single-phase AC power supply is increased. As a result, current leakage between the first electrode pair and the second electrode pair is less likely to occur, and a decrease in the power factor can be suppressed.

[0011] (2) In the configuration of (1) above, it is preferable that the row directions of the first electrode group and the second electrode group are parallel to the flow direction of the glass melting furnace, and that the first electrode group is adjacent to the upstream side of the flow direction of the second electrode group.

[0012] In this way, by relatively increasing the power supply to the first electrode group located upstream, or relatively increasing the power supply to the second electrode group located downstream, it becomes easier to adjust the temperature distribution of the molten glass in the flow direction of the glass melting furnace.

[0013] (3) In the configuration of (1) or (2) above, it is preferable that the second single-phase AC power supply has a phase difference of 1 / 4 period from the first single-phase AC power supply.

[0014] In this way, a Scott connection or similar method can be used to easily obtain a first single-phase AC power supply and a second single-phase AC power supply from a three-phase AC power supply.

[0015] (4) In any of the configurations described in (1) to (3) above, it is preferable that the eight first electrodes of the first electrode group and the eight second electrodes of the second electrode group are arranged in a 4x4 matrix, and that the spacing between adjacent first electrodes, the spacing between adjacent second electrodes, and the spacing between adjacent first electrodes and the second electrodes are all equal.

[0016] In this way, all electrodes in the first and second electrode groups are arranged at equal intervals, improving the symmetry between the electrode connections in the first and second electrode groups, and making it easier to adjust the temperature distribution inside the furnace.

[0017] (5) The present invention, which was devised to solve the above problems, is a method for manufacturing a glass article, characterized by comprising a melting step in which molten glass is formed from glass raw materials using a glass melting furnace having any of the configurations (1) to (4) above.

[0018] In this way, the same effects and benefits as the corresponding configuration described above can be enjoyed.

[0019] According to the present invention, in a glass melting furnace that heats molten glass by applying an electric current, the temperature distribution of the molten glass can be easily adjusted while suppressing a decrease in the power factor.

[0020] This is a longitudinal cross-sectional view showing a glass article manufacturing apparatus according to the first embodiment of the present invention. This is a cross-sectional view taken along line A-A in Figure 1. This figure corresponds to a cross-sectional view taken along line A-A in Figure 1 of a glass article manufacturing apparatus according to the second embodiment of the present invention. This figure corresponds to a cross-sectional view taken along line A-A in Figure 1 showing a modified example of the electrode connection of the first embodiment. This figure corresponds to a cross-sectional view taken along line A-A in Figure 1 showing a modified example of the electrode connection of the first embodiment. This figure shows an electrode connection used for numerical simulation of current value and power factor related to a comparative example. This figure shows an example of an electrode connection in a conventional glass article manufacturing apparatus.

[0021] Hereinafter, embodiments of the method for manufacturing glass articles according to the present invention will be described with reference to the drawings. In each embodiment, corresponding components will be denoted by the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the configuration of other embodiments described earlier may be applied to the other parts of that configuration. Furthermore, not only the combinations of configurations explicitly stated in the description of each embodiment, but also the configurations of multiple embodiments may be partially combined even if not explicitly stated, as long as there are no particular problems with the combination.

[0022] (First Embodiment) As shown in Figures 1 and 2, the glass article manufacturing apparatus according to the first embodiment includes a glass melting furnace 1 for forming molten glass Gm from glass raw material Gr. The glass articles manufactured by this manufacturing apparatus are not particularly limited and include, for example, glass plates (including glass films), glass rolls (equipped with a core and a glass film wound in a roll shape around the core), glass fibers, optical glass components, glass tubes, glass blocks, etc. In the figures, XYZ is a Cartesian coordinate system, where the X and Y directions are horizontal and the Z direction is vertical. The X direction is sometimes called the flow direction and the Y direction is called the width direction. Here, the flow direction is the direction from the side in which the glass raw material is fed to the side in which the molten glass is discharged, and the width direction is the direction intersecting the flow direction (in this embodiment, the direction perpendicular to the flow direction).

[0023] The glass melting furnace 1 comprises a bottom wall 1a, side walls 1b, and a ceiling wall 1c, with these walls 1a to 1c forming a space for containing molten glass Gm. The side wall 1b includes a front wall 1b1 and a rear wall 1b2 facing each other in the flow direction X, and a left wall 1b3 and a right wall 1b4 facing each other in the width direction Y. The front wall 1b1 side is the upstream side in the flow direction X, and the rear wall 1b2 side is the downstream side in the flow direction X. The front wall 1b1 has an inlet 2 above the liquid surface of the molten glass Gm. The rear wall 1b2 has an outlet 3 below the liquid surface of the molten glass Gm.

[0024] A feeder 4, such as a screw feeder, is provided at the input port 2 on the front wall 1b1 of the glass melting furnace 1 for feeding in the glass raw material Gr. A transfer pipe for transporting molten glass Gm is connected to the discharge port 3 on the rear wall 1b2 of the glass melting furnace 1, so that molten glass Gm is sequentially supplied from the glass melting furnace 1 to the downstream process. The configuration of the transfer pipe and its downstream side may be changed as appropriate depending on the type of glass product to be manufactured.

[0025] The glass melting furnace 1 comprises four first single-phase AC power supplies 5, four second single-phase AC power supplies 6 having a phase difference with respect to the first single-phase AC power supplies 5, a first electrode group 8 consisting of eight first electrodes 7 arranged in a 4x2 matrix on the bottom wall 1a, and a second electrode group 10 consisting of eight second electrodes 9 arranged in a 4x2 matrix on the bottom wall 1a at a different location adjacent to the first electrode group 8.

[0026] A pair of first single-phase AC power supplies 5 and second single-phase AC power supplies 6 are obtained by converting one three-phase AC power supply into two single-phase AC power supplies with a phase difference of 1 / 4 period between them using a Scott connection (transformer), although this is not shown in the diagram. In other words, using a Scott connection, four first single-phase AC power supplies 5 and four second single-phase AC power supplies 6 with a phase difference of 1 / 4 period relative to the first single-phase AC power supplies 5 are obtained from four three-phase AC power supplies.

[0027] The first electrode 7 and the second electrode 9 are formed from, for example, rod-shaped molybdenum (Mo). The first electrode 7 and the second electrode 9 protrude into the furnace from the bottom wall 1a of the glass melting furnace 1 and are immersed in the molten glass Gm.

[0028] In the first electrode group 8, the row direction (the direction in which two first electrodes 7 are arranged side by side) is parallel to the flow direction X, and the column direction (the direction in which four first electrodes 7 are arranged side by side) is parallel to the width direction Y. In this embodiment, each first electrode 7 is arranged at equal intervals in the row direction and the column direction. That is, the distance D1 between adjacent first electrodes 7 in the row direction (flow direction X) is equal to the distance D2 between adjacent first electrodes 7 in the column direction (width direction Y).

[0029] The second electrode group 10 is located downstream of the first electrode group 8. In the second electrode group 10, the row direction (the direction in which two second electrodes 9 are arranged) is parallel to the flow direction X, and the column direction (the direction in which four second electrodes 9 are arranged) is parallel to the width direction Y. In this embodiment, each second electrode 9 is arranged at equal intervals in the row direction and the column direction. That is, the distance D3 between adjacent second electrodes 9 in the row direction (flow direction X) is equal to the distance D4 between adjacent second electrodes 9 in the column direction (width direction Y).

[0030] The eight first electrodes 7 of the first electrode group 8 and the eight second electrodes 9 of the second electrode group 10 are arranged in a 4x4 matrix. In this embodiment, the spacing D1, D2 between adjacent first electrodes 7, the spacing D3, D4 between adjacent second electrodes 9, and the spacing D5 between adjacent first electrodes 7 and second electrodes 9 are all equal. The spacing D1 to D5 is, for example, 0.2 m to 2.0 m, and preferably 0.4 m to 1.5 m.

[0031] The two terminals о and u of the four first single-phase AC power supplies 5 are connected one by one to eight first electrodes 7 outside the furnace (for example, below the bottom wall 1a). The two terminals о' and v of the four second single-phase AC power supplies 6 are connected one by one to eight second electrodes 9. In the following explanation, the two (a pair) of first electrodes 7 connected to the pair of terminals о and u of the common first single-phase AC power supply 5 may be referred to as "first electrode pair 7a," and the two (a pair) of second electrodes 9 connected to the pair of terminals о' and v of the common second single-phase AC power supply 6 may be referred to as "second electrode pair 9a."

[0032] In all first single-phase AC power supplies 5, a pair of terminals o and u are located in different rows of the first electrode group 8 and are connected to two first electrodes 7 that are positioned one position apart in the row direction (width direction Y). That is, if the first electrode 7 connected to terminal o is located in the nth row of the first electrode group 8 (where n is 1 or 2), then the first electrode 7 connected to the paired terminal u is located in the (n+1)th or (n-1)th row of the first electrode group 8 (where n+1 and n-1 are 1 or 2). And if the first electrode 7 connected to terminal o is located in the mth row of the first electrode group 8 (where m is 1 to 4), then the first electrode 7 connected to terminal u is located in the (m+2)th or (m-2) row of the first electrode group 8 (where m+2 and m-2 are 1 to 4).

[0033] Similarly, in all second single-phase AC power supplies 6, a pair of terminals о' and v are located in different rows of the second electrode group 10 and are connected to two second electrodes 9 that are positioned one position apart in the row direction (width direction Y). That is, if the second electrode 9 connected to terminal о' is located in the p-th column of the second electrode group 10 (where p is 1 or 2), then the second electrode 9 connected to the corresponding terminal v is located in the p+1 or p-1 column of the second electrode group 10 (where p+1 and p-1 are 1 or 2). And if the second electrode 9 connected to terminal о' is located in the q-th row of the second electrode group 10 (where q is 1 to 4), then the second electrode 9 connected to the corresponding terminal v is located in the q+2 or q-2 row of the second electrode group 10 (where q+2 and q-2 are 1 to 4).

[0034] In this way, since the first electrode group 8 and the second electrode group 10 are provided at different positions on the bottom wall 1a of the glass melting furnace 1, the temperature of the molten glass Gm at different positions corresponding to each electrode group 8 and 10 can be individually adjusted by adjusting the amount of power supplied to the first electrode group 8 and / or the second electrode group 10.

[0035] Furthermore, with the above electrode connection, the electrode connection in the first electrode group 8 and the electrode connection in the second electrode group 10 are symmetrical with respect to the width direction Y. Therefore, even if the power supply to one of the electrode groups, the first electrode group 8 or the second electrode group 10, is relatively increased, asymmetrical convection is unlikely to occur in the molten glass Gm. Consequently, by adjusting the power distribution between the first electrode group 8 located upstream and the second electrode group 10 located downstream, the temperature distribution in the flow direction X of the molten glass Gm can be easily adjusted.

[0036] Furthermore, with the above electrode connection, the distance between at least one first electrode 7 of the first electrode pair 7a connected to the pair of terminals o and u of the first single-phase AC power supply 5 and at least one second electrode 9 of the second electrode pair 9a connected to the pair of terminals o' and v of the second single-phase AC power supply 6 increases. In other words, even if one first electrode 7 of the first electrode pair 7a is close to one second electrode 9 of the second electrode pair 9a, the other first electrode 7 of the first electrode pair 7a is always separated from the other second electrode 9 of the second electrode pair 9a. Therefore, current leakage between the first electrode pair 7a and between the second electrode pair 9a becomes less likely. Specifically, when considering current flow between the first electrode pair 7a, it is possible to suppress the situation in which current leaks through the path terminal o → molten glass Gm → terminal o' → wiring → terminal v → molten glass Gm → terminal u, causing a phase difference between the current and voltage between the second electrode pair 9a (terminals o' and v). Similarly, when considering current flow between the second electrode pair 9a, the current flows back through the path terminal o' → molten glass Gm → terminal o → wiring → terminal u → molten glass Gm → terminal v, which can suppress the occurrence of a phase difference between the current and voltage between the first electrode pair 7a (terminals o, u). Therefore, the decrease in power factor due to current leakage can be suppressed, and energy efficiency can be improved.

[0037] Furthermore, with the above electrode connection, the distance between the two electrodes in each pair of first electrode pairs 7a and second electrode pairs 9a is increased, which suppresses the generation of overcurrents that can cause electrode wear and other problems.

[0038] Next, a method for manufacturing glass articles using the glass article manufacturing apparatus described above will be explained.

[0039] This manufacturing method includes a melting step in which molten glass Gm is formed from glass raw material Gr using a glass melting furnace 1 provided in the glass article manufacturing apparatus described above. Additional steps may be added as appropriate, depending on the type of glass article to be manufactured. For example, additional steps after the melting step may include a clarification step for clarifying the formed molten glass, a stirring step for stirring the molten glass, a molding step for shaping a glass article from the molten glass, and a processing step for processing the shaped glass article (e.g., cutting, grinding, polishing, washing, inspection, etc.).

[0040] (Second Embodiment) As shown in Figure 3, the glass article manufacturing apparatus according to the second embodiment differs from the glass article manufacturing apparatus according to the first embodiment in the manner of electrode connection in the glass melting furnace 1.

[0041] In detail, in this embodiment, in the 4 rows x 2 columns first electrode group 8, the row direction (the direction in which two first electrodes 7 are arranged) is parallel to the width direction Y, and the column direction (the direction in which four first electrodes 7 are arranged) is parallel to the flow direction X.

[0042] The second electrode group 10 is provided on one side of the first electrode group 8 in the width direction Y. In the 4 rows x 2 columns of the second electrode group 10, the row direction (the direction in which the two second electrodes 9 are arranged) is parallel to the width direction Y, and the column direction (the direction in which the four second electrodes 9 are arranged) is parallel to the flow direction X.

[0043] Each pair of terminals о, u of the first single-phase AC power supply 5 is connected to two first electrodes 7, which are located in different rows of the first electrode group 8 and are positioned at alternate positions in the row direction (flow direction X). Similarly, each pair of terminals о', v of the second single-phase AC power supply 6 is connected to two second electrodes 9, which are located in different rows of the second electrode group 10 and are positioned at alternate positions in the row direction (flow direction X).

[0044] In this way, the temperature distribution of the molten glass Gm in the width direction Y can be easily adjusted by adjusting the power distribution between the first electrode group 8 located on one side in the width direction Y and the second electrode group 10 located on the other side in the width direction Y. Furthermore, as in the first embodiment, the decrease in the power factor due to current leakage can also be suppressed.

[0045] Note that the present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. The present invention can be variously modified without departing from the gist of the present invention.

[0046] In the above embodiment, the case where (1) the intervals D1 and D2 between adjacent first electrodes 7, (2) the intervals D3 and D4 between adjacent second electrodes 9, and (3) the interval D5 between adjacent first electrode 7 and second electrode 9 are all equal has been described. However, the present invention is not limited to this configuration. For example, at least one of the intervals (1) to (3) may be different from the other intervals. Specifically, as shown in FIG. 4, the intervals D1 and D2 between adjacent first electrodes 7 may be different from the intervals D3 and D4 between adjacent second electrodes 9 (for example, D1 = D2, D3 = D4, and D1 > D3). Alternatively, as shown in FIG. 5, the intervals D1 and D2 between adjacent first electrodes 7 and the intervals D3 and D4 between adjacent second electrodes 9 may be different from the interval D5 between adjacent first electrode 7 and second electrode 9 (for example, D1 = D2 = D3 = D4 and D1 < D5).

[0047] In the above embodiment, the case where one electrode group of 4 rows × 4 columns composed of a first electrode group 8 of 4 rows × 2 columns and a second electrode group 10 of 4 rows × 2 columns is arranged on the bottom wall 1a of the glass melting furnace 1 has been described. However, the number of this 4 rows × 4 columns electrode group may be appropriately changed according to the size of the glass melting furnace 1. That is, a plurality of electrode groups of 4 rows × 4 columns composed of a first electrode group 8 of 4 rows × 2 columns and a second electrode group 10 of 4 rows × 2 columns may be arranged on the bottom wall 1a of the glass melting furnace 1. Further, if the energization heating by the first electrode group 8 and the second electrode group 10 is dominant, an electrode group (including at least one electrode pair) having a different electrode connection mode may be further arranged.

[0048] In the above embodiment, as a method for converting a three-phase AC power supply into a single-phase AC power supply, a Scott connection (transformer) has been exemplified. However, the method for configuring a single-phase AC power supply is not particularly limited. For example, when converting a three-phase AC power supply into a single-phase AC power supply, a Woodbridge connection (transformer), a modified Woodbridge connection (transformer), a loop delta connection (transformer), or the like may be used.

[0049] The following describes examples of the glass melting furnace according to the present invention. Note that the following examples are merely illustrative, and the present invention is not limited in any way to these examples.

[0050] The examples and comparative examples are subject to the following conditions: <Numerical Simulation Conditions> (1) Conditions for molten glass - The depth of the molten glass is 1 m. - The conductivity of the molten glass is 16 S / m. (2) Conditions for electrodes - 16 electrodes are arranged in a 4x4 matrix. - The spacing between adjacent electrodes in the flow direction X and width direction Y is 1 m each. - The distance from the outermost electrode of the 16 electrodes to the side wall of the glass melting furnace is 0.5 m. - The projection length of the electrode from the bottom wall into the furnace is 0.5 m. - The electrodes are cylindrical conductors with a diameter of 100 mm. - The conductivity of the electrodes is 3 x 10 ６ The ratio is S / m. (3) Conditions for single-phase AC power supplies: - Four first single-phase AC power supplies and four second single-phase AC power supplies are provided. - The phase difference between the voltage of the first single-phase AC power supplies and the voltage of the second single-phase AC power supplies is 1 / 4 period. - 50 kW of power is supplied to terminals о, u of all first single-phase AC power supplies and terminals о', v of the second single-phase AC power supplies.

[0051] In the embodiment, the electrode connection shown in Figure 2 above is used. The electrode connection in the embodiment is as described above, so no further explanation is given. On the other hand, in the comparative example, the electrode connection shown in Figure 6 is used. In the comparative example, in all first single-phase AC power supplies 21, a pair of terminals о, u are connected to two first electrodes 23 that are located in the same column of the 4x2 first electrode group 22 and are spaced one position apart in the column direction (width direction Y). Also in the comparative example, in all second single-phase AC power supplies 24, a pair of terminals о', v are connected to two second electrodes 26 that are located in the same column of the 4x2 second electrode group 25 and are spaced one position apart in the column direction (width direction Y). In the figure, 27 represents the side wall of the glass melting furnace.

[0052] Based on the above conditions, numerical simulations were performed for the examples and comparative examples, and the current values ​​and power factors were calculated. The maximum current and power factor for each electrode pair are shown in Table 1 below.

[0053]

[0054] According to Table 1 above, it can be confirmed that the power factor of the example is higher than that of the comparative example. Furthermore, the maximum current value of the example is lower than that of the comparative example, confirming that overcurrent can be suppressed.

[0055] 1 Glass melting furnace 1a Bottom wall 1b Side wall 1c Top wall 2 Input port 3 Discharge port 4 Supply machine 5 First single-phase AC power supply 6 Second single-phase AC power supply 7 First electrode 7a First electrode pair 8 First electrode group 9 Second electrode 9a Second electrode pair 10 Second electrode group Gm Molten glass Gr Glass raw material o, u Terminals of the first single-phase AC power supply o', v Terminals of the second single-phase AC power supply X Flow direction Y Width direction

Claims

1. A glass melting furnace for electrically heating molten glass, comprising: four first single-phase AC power supplies; four second single-phase AC power supplies having a phase difference with the first single-phase AC power supplies; a first electrode group consisting of eight first electrodes arranged in a 4x2 matrix on the bottom wall of the glass melting furnace; and a second electrode group consisting of eight second electrodes arranged in a 4x2 matrix on the bottom wall at a different location adjacent to the first electrode group, wherein two terminals of each of the first single-phase AC power supplies are included in different rows of the first electrode group and connected to two of the first electrodes located at positions skipping one position in the row direction; and two terminals of each of the second single-phase AC power supplies are included in different rows of the second electrode group and connected to two of the second electrodes located at positions skipping one position in the row direction.

2. The glass melting furnace according to claim 1, wherein the row directions of the first electrode group and the second electrode group are parallel to the flow direction of the glass melting furnace, and the first electrode group is adjacent to the second electrode group on the upstream side in the flow direction.

3. The glass melting furnace according to claim 1 or 2, wherein the second single-phase AC power supply has a phase difference of 1 / 4 period from the first single-phase AC power supply.

4. The glass melting furnace according to claim 1 or 2, wherein the eight first electrodes of the first electrode group and the eight second electrodes of the second electrode group are arranged in a 4x4 matrix, and the spacing between adjacent first electrodes, the spacing between adjacent second electrodes, and the spacing between adjacent first electrodes and second electrodes are all equal.

5. A method for manufacturing a glass article, characterized by comprising a melting step of forming molten glass from glass raw materials using a glass melting furnace according to claim 1 or 2.

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