Device for producing glass article and method for producing glass article

Abstract

A device (11) for producing a glass article comprises a melting furnace (12) that produces molten glass (G2) by heating and melting a glass raw material (G1) and a raw material supply machine (13) that supplies the glass raw material (G1) to the melting furnace (12). The raw material supply machine (13) is provided with a container (14) that can accommodate the glass raw material (G1) and a screw feeder (15) that feeds out the glass raw material (G1) in the container (14) onto the molten glass (G2). The screw feeder (15) includes a first screw feeder (16) and a second screw feeder (17) that are disposed adjacently in the horizontal direction. The container (14) includes a shared container (18) that is shared by the first screw feeder (16) and the second screw feeder (17).

Description

Manufacturing apparatus for glass articles and manufacturing method for glass articles 【0001】 The present invention relates to a manufacturing apparatus for glass articles and a manufacturing method for glass articles. 【0002】 As described in Patent Document 1, molten glass for manufacturing glass articles can be produced using a melting furnace that melts glass raw materials. A raw material feeder for supplying the glass raw materials into the melting furnace is connected to the side wall of the melting furnace. The raw material feeder includes a container capable of storing the glass raw materials and a screw feeder that sends out the glass raw materials in the container into the melting furnace. 【0003】 Japanese Patent Application Laid-Open No. 2010-222217 【0004】 When the raw material feeder for supplying glass raw materials to the melting furnace as described above includes a plurality of screw feeders, the space around the melting furnace is narrowed by a plurality of containers provided corresponding to the plurality of screw feeders. As a result, for example, it may be difficult to secure a space for performing maintenance work on the melting furnace. 【0005】 An object of the present invention is to provide a manufacturing apparatus for glass articles and a manufacturing method for glass articles that enable easy securing of the space around the melting furnace. 【0006】 Each aspect of the manufacturing apparatus for glass articles and the manufacturing method for glass articles that solve the above problems will be described. The manufacturing apparatus for glass articles according to Aspect 1 is a manufacturing apparatus for glass articles including a melting furnace that generates molten glass by heating and melting glass raw materials, and a raw material feeder that supplies the glass raw materials to the melting furnace. The raw material feeder includes a container capable of accommodating the glass raw materials and a screw feeder that sends out the glass raw materials in the container onto the molten glass. The screw feeder includes a first screw feeder and a second screw feeder arranged adjacent to each other along the horizontal direction, and the container includes a common container common to the first screw feeder and the second screw feeder. According to this configuration, the first screw feeder, the second screw feeder, and the common container can be arranged around the melting furnace as one supply unit. 【0007】 In the glass article manufacturing apparatus of Embodiment 2, if the distance between the first screw feeder and the second screw feeder is defined as the first distance D1, the distance between the first screw feeder and the side wall of the melting furnace adjacent to the first screw feeder at a position opposite the second screw feeder, and the member of the third screw feeder adjacent to the first screw feeder that is closer to the first screw feeder, is defined as the second distance D2, and the distance between the first screw feeder and the side wall of the melting furnace adjacent to the second screw feeder at a position opposite the first screw feeder, and the member of the third screw feeder adjacent to the second screw feeder that is closer to the second screw feeder, is defined as the third distance D3, then the relationship represented by the following formulas (1) and (2) may be satisfied. 【0008】 D2 > D1 ... (1) D3 > D1 ... (2) With this configuration, by making the first distance D1 narrower than the second distance D2 and the third distance D3, the space around the melting furnace on the sides of the first screw feeder and the second screw feeder can be expanded. 【0009】 In the glass article manufacturing apparatus of Embodiment 3, in Embodiment 1 or Embodiment 2, when the first screw feeder and the second screw feeder are viewed from inside the melting furnace, the first screw feeder may be positioned to the left of the second screw feeder, the first screw feeder may be equipped with a first screw that feeds the glass raw material by rotating clockwise, and the second screw feeder may be equipped with a second screw that feeds the glass raw material by rotating counterclockwise. 【0010】 With this configuration, the first screw feeder can deliver the glass raw material biased to the opposite side from the second screw feeder. The second screw feeder can deliver the glass raw material biased to the opposite side from the first screw feeder. This promotes the diffusion of the glass raw material along the width direction of the melting furnace. 【0011】 In the glass article manufacturing apparatus of Embodiment 4, in any one of Embodiments 1 to 3, when the first screw feeder and the second screw feeder are viewed from inside the melting furnace, the first screw feeder is positioned to the left of the second screw feeder, and each of the first screw feeder and the second screw feeder comprises a supply pipe and a screw positioned inside the supply pipe, and the open end faces of the supply pipes of the first screw feeder and the second screw feeder are formed by inclined surfaces, and the most protruding tip of the supply pipe of the first screw feeder on the inclined surface is located within a range of 5° to 85° counterclockwise when the vertical downward direction is defined as 0° when viewed from inside the melting furnace, and the most protruding tip of the supply pipe of the second screw feeder on the inclined surface may be located within a range of 5° to 85° clockwise when the vertical downward direction is defined as 0° when viewed from inside the melting furnace. 【0012】 This configuration makes it possible to suppress the flow of glass raw materials fed from the supply pipe of the first screw feeder toward the second screw feeder. Furthermore, it is possible to suppress the flow of glass raw materials fed from the supply pipe of the second screw feeder toward the first screw feeder. This promotes the diffusion of glass raw materials along the width direction of the melting furnace. 【0013】 In the glass article manufacturing apparatus of embodiment 5, in embodiment 4, the tip position of the blade portion in the axial direction of the screw in the first screw feeder and the tip position of the blade portion in the axial direction of the screw in the second screw feeder may be arranged within a range from the tip of the opening end face of the supply pipe (0 mm) to a position 200 mm from the tip toward the base end of the supply pipe. This configuration makes it possible to further promote the diffusion of glass raw material along the width direction of the melting furnace. 【0014】The method for manufacturing a glass article according to embodiment 6 comprises a melting step of obtaining molten glass by melting the glass raw material using the melting furnace and raw material supply machine of the glass article manufacturing apparatus. This method makes it possible to easily secure space around the melting furnace. 【0015】 In the manufacturing method of the glass article of embodiment 7, in embodiment 6, the molten glass in the melting furnace may be heated by resistance heating in the melting step. This method makes it possible to increase the energy efficiency used for heating in the melting step. 【0016】 This invention has the effect of making it possible to easily secure space around the melting furnace. 【0017】 Figure 1 is a cross-sectional view showing the melting furnace in this embodiment. Figure 2 is a cross-sectional view along line 2-2 in Figure 1. Figure 3 is a cross-sectional view of the glass article manufacturing apparatus along line 3-3 in Figure 2. Figure 4 is a longitudinal cross-sectional view showing the pipes constituting the supply pipe of the raw material supply machine. Figure 5 is a front view showing the raw material supply machine. Figure 6 is a partial cross-sectional view along line 6-6 in Figure 5. Figure 7 is a partial cross-sectional view along line 7-7 in Figure 5. Figure 8 is a partial cross-sectional view along line 8-8 in Figure 5. Figure 9 is a cross-sectional view of a modified example of the glass article manufacturing apparatus. Figure 10 is an explanatory diagram illustrating the measurement of the maximum supply width of glass raw materials. 【0018】 The following describes embodiments of the glass article manufacturing apparatus and the glass article manufacturing method with reference to the drawings. Note that, for the sake of clarity, some parts of the components may be exaggerated or simplified in the drawings. Furthermore, the dimensional ratios of each part may differ from those of the actual components. 【0019】 <Glass Article Manufacturing Apparatus> As shown in Figures 1 and 2, the glass article manufacturing apparatus 11 includes a melting furnace 12 that generates molten glass G2 by heating and melting glass raw material G1, and a raw material supply machine 13 that supplies glass raw material G1 to the melting furnace 12. The X, Y, and Z axes in the drawings are mutually orthogonal axes, with the X axis aligning with the flow direction of the molten glass G2 in the melting furnace 12. The Y axis aligning with the width direction of the melting furnace 12. The Z axis aligning with the vertical direction. 【0020】 (Melting Furnace) The melting furnace 12 has a bottom wall 12a, a side wall 12b, and an upper wall 12c. The bottom wall 12a, side wall 12b, and upper wall 12c of the melting furnace 12 are made of, for example, a refractory material. Examples of refractory materials include electroformed bricks and fired bricks. Examples of electroformed bricks include zirconia-based electroformed bricks, alumina-based electroformed bricks, alumina-zirconia-based electroformed bricks, and alumina-zirconia-silica-based electroformed bricks. Examples of fired bricks include dense zircon bricks, dense chromium bricks, alumina-zirconia bricks, and mullite bricks. 【0021】 The side wall 12b of the melting furnace 12 has an inlet P1 for introducing glass raw material G1 into the melting furnace 12 and an outlet P2 for discharging molten glass G2 from the melting furnace 12. The inlet P1 and the outlet P2 are provided on opposite side walls 12b. The inlet P1 is positioned above the liquid level of molten glass G2 in the melting furnace 12. The outlet P2 is positioned below the liquid level of molten glass G2 in the melting furnace 12. 【0022】 The melting furnace 12 is equipped with a heating device for heating the glass raw material G1 and the molten glass G2. Examples of heating devices include a burner that injects a flame into the melting furnace 12, and a resistance heating device equipped with multiple electrodes for heating the molten glass G2 by resistance heating. For example, in steady-state operation in which the glass raw material G1 is continuously fed in and the molten glass G2 is continuously discharged, it is preferable to use the resistance heating device preferentially. The multiple electrodes of the resistance heating device are arranged to protrude into the molten glass G2 from at least one of the inner surface of the bottom wall 12a and the inner surface of the side wall 12b of the melting furnace 12. In resistance heating, the molten glass G2 is heated by Joule heat generated by passing an electric current through the molten glass G2 using each electrode. In resistance heating, it is possible to adjust the thermal energy applied to the molten glass G2 by adjusting the voltage applied to each electrode. Examples of electrode materials include molybdenum, platinum, platinum-rhodium, and tin oxide. Examples of electrode shapes include rod-shaped and plate-shaped. 【0023】In the steady-state operation described above, the proportion of the thermal energy generated by the electrodes to the total thermal energy generated by the electrodes and burner is preferably 80% or more, and more preferably 90% or more. The higher the proportion of thermal energy generated by the electrodes, the higher the energy efficiency of the melting furnace 12 can be. It is even more preferable that the proportion of thermal energy generated by the electrodes to the total thermal energy generated by the electrodes and burner is 100%, that is, that the molten glass G2 is heated using only the resistance heating device. Before the steady-state operation of the melting furnace 12 described above is started, heating by the burner can be used preferentially. Furthermore, even during steady-state operation, the melting rate of the glass raw material G1 may be adjusted by temporarily using the burner. 【0024】 (Raw material supply machine) The raw material supply machine 13 includes a container 14 capable of storing glass raw material G1 and a screw feeder 15 that sends the glass raw material G1 in the container 14 onto the molten glass G2. 【0025】 The screw feeder 15 includes a first screw feeder 16 and a second screw feeder 17 arranged adjacent to each other horizontally. The container 14 includes a common container 18 common to the first screw feeder 16 and the second screw feeder 17. The common container 18 is configured to supply glass raw materials G1 from within the common container 18 to both the first screw feeder 16 and the second screw feeder 17. Examples of the common container 18 include a hopper, a silo, etc., and these may be combined. Glass raw materials G1 are supplied to this common container 18, for example, from a batch bin. The raw material supply machine 13 includes a supply unit in which the first screw feeder 16, the second screw feeder 17, and the common container 18 are integrated. The common container 18 is arranged to connect the first screw feeder 16 and the second screw feeder 17. 【0026】Next, the details of the screw feeder 15 will be described. As shown in Figure 3, when the first screw feeder 16 and the second screw feeder 17 are viewed from inside the melting furnace 12, the first screw feeder 16 is located to the left of the second screw feeder 17. The first screw feeder 16 comprises a first supply pipe 16a and a first screw 16b located inside the first supply pipe 16a. The second screw feeder 17 comprises a second supply pipe 17a and a second screw 17b located inside the second supply pipe 17a. The shapes of the first supply pipe 16a and the second supply pipe 17a can be, for example, cylindrical. The peripheral walls of the first supply pipe 16a and the second supply pipe 17a may have passages for a cooling medium such as a coolant or cooling gas. The materials for the first supply pipe 16a and the second supply pipe 17a can be, for example, metal. The materials for the first screw 16b and the second screw 17b can be, for example, metal. 【0027】 The inner diameter of the first supply pipe 16a and the second supply pipe 17a is, for example, within the range of 100 mm or more and 650 mm or less. The thickness of the first supply pipe 16a and the second supply pipe 17a is, for example, within the range of 10 mm or more and 100 mm or less. Here, the thickness is calculated by (outer diameter - inner diameter) / 2. 【0028】 As shown in Figures 1 and 2, the first screw feeder 16 and the second screw feeder 17 are equipped with a drive unit 19 that rotates the first screw 16b and the second screw 17b. The drive unit 19 may be configured to rotate the first screw 16b and the second screw 17b using a common motor, or it may be configured to rotate the first screw 16b and the second screw 17b using independent motors. By adjusting the rotational speed of the first screw 16b and the second screw 17b, the supply speed of the glass raw material G1 can be adjusted. 【0029】 As shown in Figures 3, 5 to 8, each of the first screw 16b and the second screw 17b is equipped with a rotating shaft R and a blade portion B provided on the rotating shaft R. The shape of the blade portion B is, for example, helical. 【0030】 In this embodiment, the first screw 16b feeds out the glass raw material G1 by rotating clockwise Ra. The blade portion B of the first screw 16b has a right-handed spiral shape when viewed from inside the melting furnace 12. In other words, the blade portion B of the first screw 16b has a clockwise spiral shape when viewed from inside the melting furnace 12, from front to back. 【0031】 In this embodiment, the second screw 17b of the second screw feeder 17 feeds out the glass raw material G1 by rotating counterclockwise Rb. The blade portion B of the second screw 17b has a left-handed spiral shape when viewed from inside the melting furnace 12. In other words, the blade portion B of the second screw 17b has a counterclockwise spiral shape when viewed from inside the melting furnace 12, from front to back. 【0032】 When the distance between the first screw feeder 16 and the second screw feeder 17 is defined as the first distance D1, it is preferable that the second distance D2 and the third distance D3 satisfy the following relationships given by equations (1) and (2). 【0033】 D2 > D1 ... (1) D3 > D1 ... (2) The second distance D2 is the distance between the side wall 12b of the melting furnace 12 adjacent to the first screw feeder 16 at a position opposite the second screw feeder 17 and the first screw feeder 16. 【0034】 The third distance D3 is the distance between the side wall 12b of the melting furnace 12 adjacent to the second screw feeder 17, at a position opposite the first screw feeder 16, and the first screw feeder 16. 【0035】 In formula (1) above, it is more preferable that D2 > D1 × 2, and even more preferable that D2 > D1 × 5. In formula (2) above, it is more preferable that D3 > D1 × 2, and even more preferable that D3 > D1 × 5. The first distance D1 is, for example, within the range of 10 mm or more and 250 mm or less. 【0036】As shown in Figure 4, the first supply pipe 16a of the first screw feeder 16 and the second supply pipe 17a of the second screw feeder 17 can each be made from a pipe body 20. The pipe body 20 in this embodiment has an open end surface made of an inclined surface F. The inclination angle θF of the inclined surface F with respect to the axis L of the pipe body 20 is preferably in the range of 20° or more and 80° or less, and more preferably in the range of 30° or more and 60° or less. The inclined surface F of the pipe body 20 has a tip portion T which is the most protruding part. 【0037】 As shown in Figures 5 to 7, the open end face of the first supply pipe 16a has a first inclined surface F1. The open end face of the first supply pipe 16a, i.e., the first inclined surface F1, has a first tip portion T1. As shown in Figures 5 and 8, the open end face of the second supply pipe 17a has a second inclined surface F2. The open end face of the second supply pipe 17a, i.e., the second inclined surface F2, has a second tip portion T2. 【0038】 As shown in Figure 5, the first tip T1 on the first inclined surface F1 of the first supply pipe 16a is preferably located within a range of 5° to 85° counterclockwise, with vertically downward as viewed from inside the melting furnace 12 (0°). The angle at which the first tip T1 is located is indicated by the first angle θ1 in Figure 5. The first angle θ1 is more preferably within a range of 20° to 80°. In this embodiment, the first angle θ1 is 60°. 【0039】 The second tip T2 on the second inclined surface F2 of the second supply pipe 17a is preferably located within a range of 5° to 85° clockwise, with the vertical downward direction as viewed from inside the melting furnace 12 being 0°. The angle at which the second tip T2 is located is shown as the second angle θ2 in Figure 5. The second angle θ2 is more preferably within a range of 20° to 80°. In this embodiment, the second angle θ2 is 60°. 【0040】As shown in Figure 6, it is preferable that the tip position Ba of the blade portion B in the axial direction of the first screw 16b in the first screw feeder 16 is located within the first range E1. The first range E1 is defined as the position of the first tip portion T1 of the open end face of the first supply pipe 16a being 0 mm, and the range extending from the first tip portion T1 to a position 200 mm toward the base end of the first supply pipe 16a. 【0041】 As shown in Figure 8, it is preferable that the tip position Ba of the blade portion B in the axial direction of the second screw 17b in the second screw feeder 17 is located within the second range E2. The second range E2 is defined as the position of the second tip portion T2 of the open end face of the second supply pipe 17a being 0 mm, and the range extending from the second tip portion T2 to a position 200 mm toward the base end of the second supply pipe 17a. 【0042】 (Other configurations) The glass article manufacturing apparatus 11 includes one or more molding devices, which are not shown in the figures. The molding devices form glass articles from molten glass G2 produced in the melting furnace 12. Examples of glass molding methods in the molding device include the down-draw method, roll-out method, float method, blow molding method, press molding method, fiber molding method, and Danner method. Examples of the down-draw method include the overflow down-draw method and the slot down-draw method. The glass article manufacturing apparatus 11 may also include a clarification tank, a stirring tank, a fore hearth, etc., as needed. 【0043】 <Method for Manufacturing Glass Articles> Next, a method for manufacturing glass articles will be described. The method for manufacturing glass articles includes a melting step in which glass raw material G1 is melted using the melting furnace 12 and raw material supply machine 13 of the glass article manufacturing apparatus 11 to obtain molten glass G2. 【0044】As shown in FIGS. 1 and 2, in the melting process, molten glass G2 is continuously produced by melting the glass raw material G1 continuously supplied into the melting furnace 12. For heating inside the melting furnace 12 in the melting process, the above-described burner, resistance heating, etc. can be used. In the melting process, it is preferable to heat the molten glass G2 in the melting furnace 12 by resistance heating. By resistance heating the molten glass G2 in the melting furnace 12, the glass raw material G1 supplied onto the liquid surface of the molten glass G2 can be melted. 【0045】 In the melting process in the method for manufacturing a glass article, the glass raw material G1 in the melting furnace 12 covers at least a part of the liquid surface of the molten glass G2 in the melting furnace 12. The glass raw material G1 in the melting process preferably covers a liquid surface having an area of 60% or more when the area of the entire liquid surface of the molten glass G2 in the melting furnace 12 is taken as 100%. In this case, it becomes possible to suppress heat radiation from the molten glass G2 by the glass raw material G1. Thereby, it becomes possible to reduce the energy for heating the molten glass G2. The area where the glass raw material G1 covers the liquid surface of the molten glass G2 can be adjusted, for example, by the supply rate of the glass raw material G1 supplied into the melting furnace 12, the temperature of the molten glass G2, the ambient temperature in the melting furnace 12, and the like. 【0046】 Examples of the glass obtained from the glass raw material G1 include glass for fibers, non-alkali glass, soda glass, soda-lime glass, borosilicate glass, aluminosilicate glass, alkali-containing glass, and the like. 【0047】 Examples of the glass raw material G1 include silica sand, lime, aluminum oxide, soda ash, boric acid, colemanite, kaolinite, pyrophyllite, calcium carbonate, dolomite, zircon, and the like. The glass raw material G1 may contain recycled raw materials such as cullet and recycled glass fibers for recycling. When the glass raw material G1 contains cullet, the content of cullet is preferably 50% by mass or less. A fining agent can also be added to the molten glass G2. Examples of the fining agent include sodium sulfate, calcium sulfate, colemanite, and the like. 【0048】The manufacturing method of the glass article includes a forming step of obtaining the glass article by forming the molten glass G2 obtained in the above melting step. The forming step can use the glass forming method described above. Examples of the shape of the glass article include plate shape, tubular shape, rod shape,块状, fibrous shape, etc. The manufacturing method of the glass article may include a fining step of removing bubbles from the molten glass G2, a stirring step of stirring the molten glass G2 to homogenize it, etc., as necessary. 【0049】 【0050】 【0051】 <Actions and Effects of the Embodiment> Next, the actions and effects of the embodiment will be described. (1) The manufacturing apparatus 11 of the glass article includes a melting furnace 12 that generates molten glass G2 by heating and melting the glass raw material G1, and a raw material feeder 13 that supplies the glass raw material G1 to the melting furnace 12. The raw material feeder 13 of the manufacturing apparatus 11 of the glass article includes a container 14 that can store the glass raw material G1, and a screw feeder 15 that sends out the glass raw material G1 in the container 14 onto the molten glass G2. The screw feeder 15 includes a first screw feeder 16 and a second screw feeder 17 that are arranged adjacent to each other along the horizontal direction. The container 14 includes a common container 18 that is common to the first screw feeder 16 and the second screw feeder 17. 【0051】 ​​​(2) In the glass article manufacturing apparatus 11, it is preferable that the first distance D1, the second distance D2, and the third distance D3 satisfy the relationship between formulas (1) and (2) above. In this case, by making the first distance D1 narrower than the second distance D2 and the third distance D3, the space around the melting furnace 12 on the side of the first screw feeder 16 and the second screw feeder 17 can be increased. Therefore, for example, maintenance work on the melting furnace 12 can be made easier. 【0052】 (3) In the glass article manufacturing apparatus 11, the first screw feeder 16, located to the left of the second screw feeder 17, is equipped with a first screw 16b that feeds out the glass raw material G1 by rotating clockwise Ra. The second screw feeder 17 is equipped with a second screw 17b that feeds out the glass raw material G1 by rotating counterclockwise Rb. In this case, the first screw feeder 16 can feed out the glass raw material G1 biased to the opposite side from the second screw feeder 17. The second screw feeder 17 can feed out the glass raw material G1 biased to the opposite side from the first screw feeder 16. This promotes the diffusion of the glass raw material G1 along the width direction (Y-axis direction) of the melting furnace 12. Therefore, for example, it is possible to promote the melting of the glass raw material G1 by heat transfer from the molten glass G2, or to further suppress heat dissipation from the liquid surface of the molten glass G2. 【0053】 (4) The first tip T1 that protrudes the most on the first inclined surface F1 of the first supply pipe 16a of the first screw feeder 16 is preferably located within a range of 5° to 85° counterclockwise, with the vertical downward direction as viewed from inside the melting furnace 12 being 0°. The second tip T2 that protrudes the most on the second inclined surface F2 of the second supply pipe 17a of the second screw feeder 17 is preferably located within a range of 5° to 85° clockwise, with the vertical downward direction as viewed from inside the melting furnace 12 being 0°. 【0054】In this case, it is possible to suppress the flow of the glass raw material G1 sent from the first supply pipe 16a of the first screw feeder 16 toward the second screw feeder 17. Also, it is possible to suppress the flow of the glass raw material G1 sent from the second supply pipe 17a of the second screw feeder 17 toward the first screw feeder 16. This promotes the diffusion of the glass raw material G1 along the width direction (Y-axis direction) of the melting furnace 12. Therefore, for example, it is possible to promote the melting of the glass raw material G1 by heat transfer from the molten glass G2, or to further suppress heat dissipation from the liquid surface of the molten glass G2. 【0055】 (5) It is preferable that the tip position Ba of the blade portion B in the axial direction of the first screw 16b in the first screw feeder 16 be located within the first range E1. It is preferable that the tip position Ba of the blade portion B in the axial direction of the second screw 17b in the second screw feeder 17 be located within the second range E2. In this case, it is possible to further enhance the effects described in section (4) above. 【0056】 (6) The method for manufacturing glass articles includes a melting step in which glass raw material G1 is melted using the melting furnace 12 and raw material supply machine 13 of the glass article manufacturing apparatus 11 to obtain molten glass G2. This method makes it easy to secure space around the melting furnace 12. Therefore, by utilizing the space around the melting furnace 12, maintenance work on the melting furnace 12 can be easily performed. 【0057】 (7) In the melting step of the manufacturing method of glass articles, it is preferable to heat the molten glass G2 in the melting furnace 12 by resistance heating. In this case, the energy efficiency used for heating in the melting step can be increased. 【0058】 <Examples of Modifications> The above embodiment can be implemented with the following modifications. The above embodiment and the following examples of modifications can be combined with each other to the extent that they do not contradict each other technically. 【0059】As shown in the modified example in Figure 9, the screw feeder 15 of the raw material supply machine 13 may further include a third screw feeder 21 provided between the first screw feeder 16 and the side wall 12b of the melting furnace 12. This third screw feeder 21 is positioned adjacent to the first screw feeder 16 on the opposite side of the second screw feeder 17. The container 14 of the raw material supply machine 13 includes independent containers 22 provided independently for each third screw feeder 21. 【0060】 In this modified example, by satisfying equations (1) and (2) above, it becomes possible to easily secure space around the melting furnace 12 on the sides of the first screw feeder 16 and the second screw feeder 17. However, the second distance D2 in equation (1) is the distance between the first screw feeder 16 and the third screw feeder 21 adjacent to the first screw feeder 16 at a position opposite the second screw feeder 17. Also, the third distance D3 in equation (2) is the distance between the first screw feeder 16 and the third screw feeder 21 adjacent to the second screw feeder 17 at a position opposite the first screw feeder 16. 【0061】 In the modified example shown in Figure 9, one of the two third screw feeders 21 can be omitted. Furthermore, the screw feeder 15 of the raw material supply machine 13 may further include a fourth screw feeder provided between the third screw feeder 21 and the side wall 12b of the melting furnace 12. 【0062】 The third screw feeder 21 in the modified example shown in Figure 9 may be a screw feeder 15 that constitutes a supply unit having two screw feeders 15 and a common container 18 common to the two screw feeders 15. 【0063】 - The open end face of the first supply pipe 16a of the first screw feeder 16 may be an orthogonal surface perpendicular to the axis L of the first supply pipe 16a. The open end face of the second supply pipe 17a of the second screw feeder 17 may be an orthogonal surface perpendicular to the axis L of the second supply pipe 17a. 【0064】 The raw material feeder 13 can also be configured to feed out the glass raw material G1 by rotating the first screw 16b of the first screw feeder 16 counterclockwise instead of clockwise Ra. In this case, the blade portion B of the first screw 16b has a left-handed spiral shape when viewed from inside the melting furnace 12. 【0065】 The raw material feeder 13 can also be configured to feed out the glass raw material G1 by rotating the second screw 17b of the second screw feeder 17 clockwise instead of counterclockwise Rb. In this case, the blade portion B of the second screw 17b has a left-handed spiral shape when viewed from inside the melting furnace 12. 【0066】 - As the first screw 16b and the second screw 17b, shafted screws with blades B mounted on the rotation axis R are used, but shaftless screws without blades B mounted on the rotation axis R can also be used. A shaftless screw has a screw body consisting of blades and a drive shaft for rotating the screw body. 【0067】 <Test Example> Next, a test example will be described. (Raw Material Feeding Machine (A)) A raw material feeding machine (A) equipped with a first screw feeder, a second screw feeder, and a common container was prepared. Details of raw material feeding machine (A) are as follows. 【0068】: 0° θ1: 0° θ2: 0° θ2: 0° θ3: 0° θ4: 0° θ4: 0° θ5 【0069】 (Raw material feeder (C)) A raw material feeder (C) was prepared, having the same configuration as raw material feeder (A), except that the tip position Ba of the blades of the first screw was changed to a position 10 mm from the first tip, and the tip position Ba of the blades of the second screw was changed to a position 10 mm from the second tip. 【0070】 (Raw material feeder (D)) A raw material feeder (D) was prepared, having the same configuration as raw material feeder (A), except that the shape and rotation direction of the blades of the first screw were changed to a left-handed spiral shape and counterclockwise rotation, and the shape and rotation direction of the blades of the second screw were changed to a right-handed spiral shape and clockwise rotation. 【0071】 (Test Examples 1-4) As shown in Figure 10, in Test Example 1, the glass raw material G1 was supplied to the upper surface of the test stand 23 by using the raw material supply machine (A) as the raw material supply machine 13 to feed the glass raw material G1 onto the test stand 23. The upper surface of the test stand 23 is made of a flat metal surface. The rotation speed of the first and second screws of the raw material supply machine (A) was set to 6 rpm. The time for supplying the glass raw material G1 from the raw material supply machine (A) to the upper surface of the test stand 23 was set to 5 minutes. 【0072】Next, the maximum supply width W of the glass raw material G1 supplied onto the test stand 23 was measured. The maximum supply width W is the maximum width of the glass raw material G1 along the horizontal direction (Y-axis direction) perpendicular to the axial direction (X-axis direction) of the first screw feeder 16 and the second screw feeder 17. The wider this maximum supply width W of the glass raw material G1, the more the diffusion of the glass raw material G1 along the width direction (Y-axis direction) of the melting furnace can be promoted. 【0073】 In Test Examples 2 to 4, the maximum supply width W of the glass raw material was measured in the same manner as in Test Example 1, except that the raw material feeder (A) was changed to raw material feeder (B), raw material feeder (C), and raw material feeder (D). 【0074】 (Results for Maximum Supply Width W) The results for the maximum supply width W of the glass raw material in each test example are shown below. Test Example 1: W = 0.89 m Test Example 2: W = 0.92 m Test Example 3: W = 0.95 m Test Example 4: W = 0.88 m From the results of Test Example 1 and Test Example 2, it can be seen that by setting the first angle θ1 and the second angle θ2 as in raw material feeder (B), the maximum supply width W can be increased compared to raw material feeder (A). From the results of Test Example 1 and Test Example 3, it can be seen that by setting the tip positions Ba of the blades of the first screw and the second screw as in raw material feeder (C), the maximum supply width W can be increased compared to raw material feeder (A). From the results of Test Example 1 and Test Example 4, it can be seen that by setting the shape and rotation direction of the blades of the first screw and the second screw as in raw material feeder (A), the maximum supply width W can be increased compared to raw material feeder (D). 【0075】11...Glassware manufacturing apparatus 12...Melting furnace 12b...Side wall 13...Raw material feeder 14...Container 15...Screw feeder 16...First screw feeder 16a...First supply pipe 16b...First screw 17...Second screw feeder 17a...Second supply pipe 17b...Second screw 18...Common container 21...Third screw feeder Ba...Tip position D1...First distance D2...Second distance D3...Third distance F...Inclined surface F1...First inclined surface F2...Second inclined surface G1...Glass raw material G2...Molten glass T...Tip T1...First tip T2...Second tip

Claims

1. A glass article manufacturing apparatus comprising: a melting furnace for producing molten glass by heating and melting glass raw materials; and a raw material supply machine for supplying the glass raw materials to the melting furnace, wherein the raw material supply machine comprises: a container capable of containing the glass raw materials; and a screw feeder for feeding the glass raw materials in the container onto the molten glass, the screw feeder includes a first screw feeder and a second screw feeder arranged adjacent to each other along the horizontal direction, and the container includes a common container common to the first screw feeder and the second screw feeder.

2. A glass article manufacturing apparatus according to claim 1, wherein the distance between the first screw feeder and the second screw feeder is defined as the first distance D1, the distance between the first screw feeder and the side wall of the melting furnace adjacent to the first screw feeder at a position opposite to the second screw feeder, and the member of the third screw feeder adjacent to the first screw feeder that is closer to the first screw feeder, and the distance between the first screw feeder and the side wall of the melting furnace adjacent to the second screw feeder at a position opposite to the first screw feeder, and the member of the third screw feeder adjacent to the second screw feeder that is closer to the second screw feeder, and the distance between the first screw feeder and the side wall of the melting furnace adjacent to the second screw feeder at a position opposite to the first screw feeder, and the distance between the first screw feeder and the member of the third screw feeder adjacent to the second screw feeder that is closer to the second screw feeder, and the relationship expressed by the following formulas (1) and (2): D2 > D1 ... (1) D3 > D1 ... (2).

3. The apparatus for manufacturing glass articles according to claim 1, wherein, when the first screw feeder and the second screw feeder are viewed from inside the melting furnace, the first screw feeder is positioned to the left of the second screw feeder, the first screw feeder is equipped with a first screw that feeds the glass raw material by rotating clockwise, and the second screw feeder is equipped with a second screw that feeds the glass raw material by rotating counterclockwise.

4. When the first screw feeder and the second screw feeder are viewed from inside the melting furnace, the first screw feeder is positioned to the left of the second screw feeder, and each of the first screw feeder and the second screw feeder comprises a supply pipe and a screw positioned inside the supply pipe, and the open end faces of the supply pipes of the first screw feeder and the second screw feeder are formed of inclined surfaces, the most protruding tip of the supply pipe of the first screw feeder is located within a range of 5° to 85° counterclockwise, with vertical downward as viewed from inside the melting furnace being 0°, and the most protruding tip of the supply pipe of the second screw feeder is located within a range of 5° to 85° clockwise, with vertical downward as viewed from inside the melting furnace being 0°. The apparatus for manufacturing glass articles according to claim 1.

5. The glass article manufacturing apparatus according to claim 4, wherein the tip position of the blade portion in the axial direction of the screw in the first screw feeder and the tip position of the blade portion in the axial direction of the screw in the second screw feeder are arranged within a range from the tip of the opening end face of the supply pipe (0 mm) to a position 200 mm from the tip toward the base end of the supply pipe.

6. A method for manufacturing a glass article, comprising a melting step of obtaining molten glass by melting the glass raw material using the melting furnace and the raw material supply machine of a glass article manufacturing apparatus according to any one of claims 1 to 5.

7. The method for manufacturing a glass article according to claim 6, wherein in the melting step, the molten glass in the melting furnace is heated by resistance heating.

Images