Apparatus and method for manufacturing glass article

Abstract

To efficiently remove heterogeneous glass from a treatment tank for treating molten glass while suppressing equipment cost.SOLUTION: The glass article manufacturing apparatus 1 includes a distribution tank 6 that performs distribution processing of molten glass 3, and the distribution tank 6 has a supply port 13 for supplying the molten glass 3 into the tank, outflow ports 14 and 15 for allowing the molten glass 3 to flow out of the tank, and a discharge port 16 for discharging surface layer molten glass 3a that may contain heterogeneous glass to the outside of the tank. A shelf 12 is provided at least in a range where the discharge port 16 exists, and an upper surface 12a of the shelf 12 is positioned above the outflow ports 14, 15 and below an opening upper end 16a of the discharge port 16. Above the upper surface 12a of the shelf 12, a flow for guiding the surface layer molten glass 3a to the discharge port 16 is generated, and the heterogeneous glass can be efficiently removed from the distribution tank 6 by the flow.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a glass article manufacturing apparatus and a glass article manufacturing method using the same manufacturing apparatus. [Background technology]

[0002] Glass articles such as glass plates, glass tubes, glass fibers, etc. are manufactured from molten glass produced by melting glass raw materials in a glass melting furnace. The molten glass produced in the glass melting furnace is supplied to downstream manufacturing equipment, for example, through a distribution tank that distributes the molten glass to multiple flow paths.

[0003] When molten glass contains volatile components, the volatile components are lost from the liquid surface of the molten glass. Therefore, the surface molten glass in the distribution tank (molten glass near the liquid surface) contains extraneous glass having a different composition from the lower layer molten glass in the distribution tank (molten glass below the surface molten glass). Molten glass containing extraneous glass may cause problems when forming glass articles from the molten glass or may deteriorate the product quality of the glass article. Therefore, it is necessary to remove the extraneous glass from the distribution tank so that the extraneous glass is not supplied to manufacturing equipment downstream from the distribution tank.

[0004] Here, Patent Document 1 discloses a structure for removing extraneous glass from a melting tank of a glass melting furnace, although the structure is not intended to remove extraneous glass from a distribution tank.

[0005] In the structure disclosed in the document (see Figures 1 and 2 of the document), an outlet passage 5 for discharging molten glass 2 from a melting tank 1 protrudes from a side wall 3 of the melting tank 1. A discharge passage 6 is provided above the outlet passage 5 for discharging the surface layer molten glass 2 containing extraneous glass 7 out of the melting tank 1. This discharge passage 6 removes the extraneous glass 7 from the melting tank 1, thereby minimizing the supply of extraneous glass 7 from the melting tank 1 to the downstream side through the outlet passage 5. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 63-143533 [Non-patent literature]

[0007] [Non-Patent Document 1] Thomas P. Seward III, "High Temperature Glass Melt Property Database for Process Modeling", Wiley-American Ceramic Society Publishing, 1st edition, published September 1, 2005, p.16-17, p.95-117, p.119-130, p.131-171 Summary of the Invention [Problem to be solved by the invention]

[0008] When applying the structure disclosed in Patent Document 1 to a distribution tank, since the distribution tank often has multiple molten glass outlets, it becomes necessary to provide discharge passages corresponding to each of the multiple outlets to discharge the surface layer molten glass out of the distribution tank, which results in a problem of increased equipment costs for removing the extraneous glass.

[0009] Furthermore, even if the above-described structure is applied to a distribution tank, there are cases where extraneous glass cannot be efficiently removed. Extraneous glass is likely to be generated near the side wall of the tank, which is located far from the molten glass supply port (inlet) of the distribution tank. This is because the surface layer of molten glass near the side wall remains in the surface layer (near the liquid surface of the molten glass) in the distribution tank for a relatively long time and is therefore likely to contain extraneous glass. Therefore, even if the above-described structure is applied to a distribution tank, depending on the positional relationship between the supply port and the discharge passage of the distribution tank, for example, if both are close to each other, the discharge passage may be located in a location where there is little extraneous glass. As a result, extraneous glass cannot be efficiently removed.

[0010] The above-mentioned problem does not occur only in distribution tanks, but also in tanks that perform some kind of treatment on molten glass (hereinafter referred to as treatment tanks), including the melting tank of a glass melting furnace. In the melting tank of a glass melting furnace, extraneous glass is likely to occur near the side wall of the tank, which is located far from the glass raw material supply port.

[0011] In view of the above circumstances, the problem to be solved is to enable efficient removal of extraneous glass from a treatment tank for treating molten glass while suppressing equipment costs. [Means for solving the problem]

[0012] The first glass article manufacturing apparatus for solving the above problem is a manufacturing apparatus comprising a treatment tank for treating molten glass, the treatment tank having a supply port for supplying molten glass or glass raw material into the treatment tank, an outlet for causing the molten glass to flow out of the treatment tank and leading to manufacturing equipment downstream of the treatment tank, and an outlet located above the outlet for discharging the surface molten glass in the treatment tank out of the tank and opening on the side wall of the treatment tank, wherein when the treatment tank is viewed in a plane, the outlet and the outlet are positioned so that they do not overlap, and the outlet is positioned farther from the supply port than the outlet, and the apparatus further comprises a shelf provided along the inner wall surface of the side wall of the treatment tank, the upper surface of the shelf is located above the outlet and below the upper end of the opening of the outlet, and the shelf is provided at least in the range where the outlet is present when the treatment tank is viewed in a plane.

[0013] In the first glass article manufacturing apparatus, the discharge outlet is located farther from the supply port than the outflow port. In other words, the discharge outlet is located in a location in the treatment tank where extraneous glass is more likely to be present than the outflow port. Furthermore, in this manufacturing apparatus, a shelf is provided at least in the area where the discharge outlet is present, and the upper surface of the shelf is located above the outflow port and below the upper end of the opening of the discharge port. Above the upper surface of this shelf, a flow is generated that guides the surface molten glass toward the discharge port. Thus, the discharge outlet is located in a location where extraneous glass is more likely to be present, and the shelf generates a flow that guides the surface molten glass toward the discharge port, thereby efficiently removing the extraneous glass from the treatment tank. Furthermore, in this manufacturing apparatus, efficient removal of extraneous glass can be achieved simply by providing a shelf along the inner wall surface of the side wall of the treatment tank, thereby reducing equipment costs for removing extraneous glass.

[0014] The second glass article manufacturing apparatus is the first manufacturing apparatus described above, but with the upper surface of the shelf positioned at the same height as the lower end of the opening of the discharge outlet or lower than the lower end of the opening of the discharge outlet.

[0015] In the second glass article manufacturing apparatus, the entire opening of the discharge port is exposed above the upper surface of the shelf. This makes it easier to generate a flow above the upper surface of the shelf that guides the surface layer molten glass toward the discharge port. As a result, extraneous glass can be more efficiently removed from the treatment tank.

[0016] The third glass article manufacturing apparatus is the first or second manufacturing apparatus described above, but with an outlet opening on the side wall of the treatment tank, and a shelf provided in a continuous range from the discharge port to the outlet when the treatment tank is viewed in a plane.

[0017] In the third glass article manufacturing apparatus, a shelf is provided in a continuous range from the discharge port to the flow outlet. This makes it possible to guide the surface molten glass (molten glass that may contain foreign glass) present above the upper surface of the shelf near the flow outlet to the discharge port. This allows the foreign glass to be removed from the treatment tank more efficiently. In addition, in this manufacturing apparatus, the upper surface of the shelf acts as a roof to prevent foreign glass from flowing into the flow outlet. This is therefore advantageous in preventing foreign glass from being supplied to downstream manufacturing equipment through the flow outlet.

[0018] A fourth glass article manufacturing apparatus is the third manufacturing apparatus described above, wherein the treatment tank has a plurality of outlets.

[0019] In the fourth glass article manufacturing apparatus, the effects of the third manufacturing apparatus described above (1) guiding the surface molten glass present above the top surface of the shelf near the outlet to the discharge outlet, and (2) preventing extraneous glass from being supplied to downstream manufacturing equipment through the outlet are obtained for each of the multiple outlets.

[0020] The fifth glass article manufacturing apparatus is the third or fourth manufacturing apparatus described above, but with a configuration in which the supply port and the discharge port are arranged opposite each other when the treatment tank is viewed in a plane.

[0021] In the fifth glass article manufacturing apparatus, the supply port and the discharge port are opposed to each other, so that the surface layer molten glass containing extraneous glass in the treatment tank tends to flow to the discharge port, thereby enabling more efficient removal of extraneous glass from the treatment tank.

[0022] The sixth glass article manufacturing apparatus is any of the third to fifth manufacturing apparatuses described above, in which, when the processing tank is viewed in plan, the portion of the shelf located within the range where the outlet is present is designated as the outlet shelf, and the direction in which the molten glass flows out of the outlet is designated as the outflow direction, and the width of the upper surface of the outlet shelf along the outflow direction is 10% or more of the width along the outflow direction within the processing tank.

[0023] In the sixth glass article manufacturing apparatus, the width of the upper surface of the outlet shelf along the outflow direction is 10% or more of the width along the outflow direction in the treatment tank, thereby improving the above-mentioned (1) effect of guiding the surface molten glass present above the upper surface of the shelf near the outlet to the discharge outlet, and (2) effect of preventing foreign glass from being supplied to downstream manufacturing equipment through the outlet.

[0024] The seventh glass article manufacturing apparatus is any one of the first to sixth manufacturing apparatuses described above, in which, when the treatment tank is viewed in plan, the direction in which the surface molten glass is discharged from the discharge outlet is defined as the discharge direction, and the opening width of the discharge outlet gradually increases from the downstream side to the upstream side in the discharge direction of the surface molten glass.

[0025] In the seventh glass article manufacturing apparatus, the opening width of the discharge outlet gradually increases from the downstream side to the upstream side in the discharge direction of the surface molten glass, making it easier for the surface molten glass containing extraneous glass to flow into the discharge outlet.

[0026] An eighth glass article manufacturing apparatus for solving the above problem is a manufacturing apparatus comprising a treatment tank for treating molten glass, the treatment tank having a supply port for supplying molten glass or glass raw material into the treatment tank, an outlet for causing the molten glass to flow out of the treatment tank and leading to manufacturing equipment downstream of the treatment tank, and an outlet located above the outlet port for discharging the surface molten glass in the treatment tank out of the tank, wherein, when the treatment tank is viewed in a plane, the outlet port and the outlet port open at different positions on the side wall of the treatment tank, and the apparatus further comprises a shelf provided along the inner wall surface of the side wall of the treatment tank, the upper surface of the shelf being located above the outlet port and below the upper end of the opening of the outlet port, and the shelf being provided in a continuous range from the outlet port to the outlet port when the treatment tank is viewed in a plane.

[0027] In the eighth glass article manufacturing apparatus, a shelf is provided in a continuous range from the discharge port to the flow outlet. A flow that guides the surface molten glass to the discharge port is generated above the upper surface of the shelf. As a result, even if surface molten glass containing foreign glass is present near the flow outlet, the surface molten glass can be guided to the discharge port without flowing into the flow outlet. Therefore, the foreign glass can be efficiently removed from the treatment tank. Furthermore, in this manufacturing apparatus, the foreign glass can be efficiently removed by simply providing a shelf along the inner wall surface of the side wall of the treatment tank, which also reduces the equipment costs for removing the foreign glass.

[0028] A method for manufacturing a glass article can be carried out using any one of the manufacturing apparatuses 1 to 8. The manufacturing method includes a forming step of forming a glass article from molten glass discharged from an outlet of a treatment tank.

[0029] In this manufacturing method, the inclusion of extraneous glass in the molten glass supplied to the forming step can be minimized, thereby making it possible to prevent defects during forming of the glass article and deterioration of the product quality of the glass article caused by extraneous glass. [Effects of the Invention]

[0030] According to the glass article manufacturing apparatus of the present disclosure, when removing extraneous glass from a treatment tank that treats molten glass, it is possible to efficiently remove the extraneous glass while suppressing equipment costs. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a cross-sectional view showing an apparatus and method for manufacturing a glass article. [Figure 2] FIG. 1(a) is a perspective view showing a schematic diagram of a distribution tank, and FIG. 1(b) is a cross-sectional view showing the AA cross section of FIG. 1(a). [Figure 3] 1 is a flowchart showing the flow of a method for manufacturing a glass article. [Figure 4] FIG. 2 is a plan view schematically showing a distribution tank. [Figure 5]10 is a graph showing the results of a simulation using a distribution tank. [Figure 6] 1 is a cross-sectional view showing an apparatus and method for manufacturing a glass article. [Figure 7] 1 is a cross-sectional view showing an apparatus and method for manufacturing a glass article. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, embodiments of a glass article manufacturing apparatus and a glass article manufacturing method will be described with reference to the accompanying drawings. The X, Y, and Z directions shown in some of the drawings referred to in the description of the embodiments are directions that are perpendicular to one another.

[0033] First Embodiment As shown in Figure 1, the glass article manufacturing apparatus 1 (hereinafter simply referred to as the manufacturing apparatus 1) includes a glass melting furnace 4 that melts glass raw material 2 to produce molten glass 3, an outlet passage 5 through which the molten glass 3 flows out of the glass melting furnace 4, a distribution tank 6 that distributes the molten glass 3 that has passed through the outlet passage 5, a first flow path 7 and a second flow path 8 that circulate the molten glass 3 distributed in the distribution tank 6, and a discharge passage 9 that discharges the surface molten glass 3a (molten glass 3 that may contain foreign glass) in the distribution tank 6 out of the tank.

[0034] The glass melting furnace 4 is equipped with a melting tank 10 capable of accommodating molten glass 3. In the glass melting furnace 4, glass raw materials 2 continuously supplied onto the molten glass 3 in the melting tank 10 from a supply port 11a of a raw material supply device 11 are heated and melted by a heating device (not shown). In this way, new molten glass 3 is continuously produced. As the raw material supply device 11, for example, a screw feeder or the like is used. As the heating device, for example, a combustion burner or an electric heating device for molten glass 3 is used.

[0035] The melting tank 10 has a bottom wall, a ceiling wall, and side walls made of refractory material. The melting tank 10 has an outlet 10a for allowing the molten glass 3 to flow out from the tank into the outlet passage 5. When the side wall located at the downstream end of the flow of the molten glass 3 in the melting tank 10 is defined as a rear wall 10x, the outlet 10a opens in the rear wall 10x near the bottom surface (bottom wall) of the melting tank 10.

[0036] The outlet passage 5 has an upstream end connected to the melting tank 10 of the glass-melting furnace 4 and a downstream end connected to the distribution tank 6. As shown by arrow D1 in Fig. 1 , the outlet passage 5 allows the molten glass 3 flowing out of the melting tank 10 to flow into the distribution tank 6. The outlet passage 5 is made of a platinum or platinum alloy pipe or refractory material.

[0037] Hereinafter, details of the distribution vessel 6 will be described with reference to Figures 1 and 2. Here, in Figure 2(a) of Figures 2(a) and (b), the bottom wall 6b, top wall, and side wall 6a of the distribution vessel 6, which are made of refractory material, are omitted, and only the shelf 12 (shown in gray) provided in the distribution vessel 6 and the molten glass 3 in the distribution vessel 6 are shown. The dimension H shown in Figures 2(a) and (b) represents the height of the liquid surface 3s of the molten glass 3 in the distribution vessel 6. Furthermore, in Figure 2(a), the outflow passage 5, the first passage 7, the second passage 8, and the discharge passage 9 are omitted, and only the molten glass 3 flowing inside these passages 5, 7, 8, and 9 is shown.

[0038] In this embodiment, the distribution tank 6 corresponds to a treatment tank that performs distribution treatment of the molten glass 3. The distribution tank 6 has a supply port 13 for supplying the molten glass 3 from the outlet passage 5 to the distribution tank 6, a first outlet 14 and a second outlet 15 for causing the molten glass 3 to flow out from the distribution tank 6 to the first flow path 7 and the second flow path 8, respectively, and a discharge port 16 for discharging the surface layer molten glass 3 a from the distribution tank 6 to the discharge passage 9.

[0039] The distribution tank 6 of this embodiment has two outlets, a first outlet 14 and a second outlet 15. As a result, the distribution tank 6 distributes the molten glass 3 that has flowed into the tank into the molten glass 3 that flows into the first flow path 7 through the first outlet 14 and the molten glass 3 that flows into the second flow path 8 through the second outlet 15. Of course, this is not limitative, and as a modified example of this embodiment, the distribution tank 6 may have three or more outlets and distribute the molten glass 3 to three or more flow paths.

[0040] Although the shape of the distribution tank 6 is not particularly limited, the distribution tank 6 of this embodiment is octagonal when viewed from above (viewed from the Z direction). The supply port 13, the first outlet 14, the second outlet 15, and the discharge port 16 open at different positions on the side wall 6a of the octagonal distribution tank 6. In other words, the supply port 13, the first outlet 14, the second outlet 15, and the discharge port 16 are arranged so as not to overlap with each other in a plan view.

[0041] The supply port 13, the first outlet 14, and the second outlet 15 open near the bottom surface (bottom wall 6b) of the distribution tank 6. In this embodiment, the openings of the supply port 13, the first outlet 14, and the second outlet 15 are open so that the lower ends of the openings of these ports 13, 14, and 15 are at the same height as the bottom surface of the distribution tank 6. Of course, this is not the only option, and as a modified example of this embodiment, the lower ends of the openings of the supply port 13, the first outlet 14, and the second outlet 15 may be positioned higher than the bottom surface of the distribution tank 6.

[0042] Discharge port 16 is disposed above supply port 13, first outlet 14, and second outlet 15, and opens near the liquid level 3s of molten glass 3 in distribution tank 6. In this embodiment, upper end 16a of discharge port 16 is located above the liquid level 3s of molten glass 3, and lower end 16b of discharge port 16 is located below the liquid level 3s of molten glass 3. The shape of the opening of discharge port 16 is not particularly limited, but in this embodiment, discharge port 16 is formed in a rectangular shape when viewed from the X direction, and the upper and lower sides of the rectangle extending in the Y direction correspond to upper end 16a and lower end 16b, respectively. In this embodiment, the height of the liquid level 3s of molten glass 3 in distribution tank 6 and in discharge passage 9 is the same.

[0043] The discharge port 16 is disposed at a greater distance from the supply port 13 than the first outlet 14 and the second outlet 15. Furthermore, the discharge port 16 is disposed at a position in the distribution tank 6 that is the farthest from the supply port 13 in a plan view. This makes it easier to remove extraneous glass contained in the surface molten glass 3a in the distribution tank 6 through the discharge port 16 when the molten glass 3 contains a volatile component. The discharge port 16 is formed in a tapered shape in a plan view, and the opening width (width in the Y direction) of the discharge port 16 gradually increases from the downstream side to the upstream side in the discharge direction of the surface molten glass 3a (the same direction as the arrow D2 shown in Figures 1 and 2 ).

[0044] The supply port 13 and the discharge port 16 are arranged to face each other in the X direction when the distribution tank 6 is viewed from above. The two outlets, the first outlet 14 and the second outlet 15, are arranged to face each other in the Y direction. The first outlet 14 and the second outlet 15 are arranged midway between the supply port 13 and the discharge port 16 in the X direction. By arranging the first outlet 14 and the second outlet 15 away from the vicinity of the discharge port 16 where extraneous glass is likely to be generated, it is possible to prevent extraneous glass from flowing out of the distribution tank 6 through both outlets 14, 15 as much as possible.

[0045] The distribution vessel 6 includes a shelf 12 made of a refractory material. The shelf 12 is provided along the inner wall surface of the side wall 6a of the distribution vessel 6. In this embodiment, the shelf 12 is provided along five consecutive sides of the eight sides of the octagon formed by the side wall 6a of the distribution vessel 6 when the distribution vessel 6 is viewed from above. As a result, the shelf 12 is provided in a continuous range from the discharge port 16 to the first outlet 14 and from the discharge port 16 to the second outlet 15. Above the upper surface 12a of the shelf 12, a flow is generated that guides the surface layer molten glass 3a to the discharge port 16.

[0046] In the following description, the portion of the shelf 12 located within the range where the first outlet 14 is present and the portion of the shelf 12 located within the range where the second outlet 15 is present will be referred to as the outlet shelf 12x.

[0047] The upper surface 12a of the shelf 12 is located below the liquid level 3s of the molten glass 3 in the distribution tank 6. In other words, the entire shelf 12 is submerged in the molten glass 3 in the distribution tank 6. The upper surface 12a of the shelf 12 is, for example, a horizontal surface. The upper surface 12a of the shelf 12 is located above the first outlet 14 and the second outlet 15. As a result, the outlet shelves 12x provided adjacent to the first outlet 14 and the second outlet 15 form roofs of the first outlet 14 and the second outlet 15, respectively. The upper surface 12a of the shelf 12 is located below the opening upper end 16a of the discharge port 16. In this embodiment, the upper surface 12a of the shelf 12, the opening lower end 16b of the discharge port 16, and the bottom surface 9a of the discharge passage 9 are at the same height.

[0048] When the direction in which the molten glass 3 flows out of the first outlet 14 and the second outlet 15 (the same direction as the arrows D3 and D4 shown in FIGS. 1 and 2 ) is defined as the outflow direction, the width W2 of the upper surface 12a of the outlet shelf 12x along the outflow direction is 10% or more of the width W1 along the outflow direction within the distribution tank 6. In other words, the relationship (W2 / W1)×100≧10 is satisfied. The “width W2” in this relationship does not refer to the sum of the width of the outlet shelf 12x adjacent to the first outlet 14 and the width of the outlet shelf 12x adjacent to the second outlet 15, but refers to the width of each of the outlet shelves 12x, 12x. Note that if the value of (W2 / W1)×100 is too large, it may be difficult for the molten glass 3 to flow out of the first outlet 14 and the second outlet 15, making it difficult to ensure the flow rate of the molten glass 3 to be circulated through the first flow path 7 and the second flow path 8. Therefore, it is preferable to determine the width W2 so as to satisfy the relationship (W2 / W1) × 100 ≦ 50, and it is more preferable to determine the width W2 so as to satisfy the relationship (W2 / W1) × 100 ≦ 25. These relational expressions also apply when the outlet shelf 12x is provided adjacent to only one of the first outlet 14 and the second outlet 15, as will be described later.

[0049] As a modification of this embodiment, the outlet shelf 12x adjacent to the first outlet 14 may have a different width W2 from the outlet shelf 12x adjacent to the second outlet 15. Furthermore, as a modification of this embodiment, the outlet shelf 12x may be provided adjacent to only one of the first outlet 14 and the second outlet 15. For example, of the first outlet 14 and the second outlet 15, the outlet shelf 12x may be provided adjacent to only the outlet through which the molten glass 3 used in the production of glass articles that require high quality passes. In this way, defects in the product quality of the glass articles can be efficiently avoided.

[0050] The shelf 12 is placed on the bottom surface (bottom wall 6b) of the distribution tank 6, and the lower surface of the shelf 12 is in contact with the bottom surface of the distribution tank 6. The side surface 12b of the shelf 12 is an upright surface that is perpendicular to the bottom surface of the distribution tank 6. Of course, this is not limited to this, and as a modification of this embodiment, the side surface 12b of the shelf 12 may be an inclined surface that is inclined with respect to the bottom surface of the distribution tank 6. An opening 12xa that serves as a passage for the molten glass 3 from inside the distribution tank 6 toward the first outlet 14 or the second outlet 15 is formed in the side surface 12b of the outlet shelf 12x.

[0051] As shown in Fig. 1, the upstream end of each of the first flow path 7 and the second flow path 8 is connected to the distribution tank 6. Meanwhile, the downstream end of each of the first flow path 7 and the second flow path 8 is connected to a manufacturing facility included in the manufacturing apparatus 1 (the manufacturing facility downstream of the distribution tank 6). The first flow path 7 and the second flow path 8 circulate the molten glass 3 flowing out of the distribution tank 6, as shown by arrows D3 and D4 in Fig. 1, respectively. In this way, the molten glass 3 is supplied to the manufacturing facility.

[0052] The discharge passage 9 has an upstream end connected to the distribution tank 6. As shown by arrow D2 in FIG. 1 , the discharge passage 9 circulates the surface layer molten glass 3 a that has flowed from the distribution tank 6 into the discharge passage 9 through the discharge port 16. The discharge passage 9 is provided with a flow rate adjustment mechanism (not shown) that adjusts the flow rate of the surface layer molten glass 3 a flowing through the passage. In this embodiment, as described above, the bottom surface 9 a of the discharge passage 9 and the opening lower end 16 b of the discharge port 16 are at the same height as the upper surface 12 a of the shelf 12. However, as a modification of this embodiment, the bottom surface 9 a of the discharge passage 9 and the opening lower end 16 b of the discharge port 16 may be positioned lower than the upper surface 12 a of the shelf 12.

[0053] A method for manufacturing a glass article using the above manufacturing apparatus 1 will now be described.

[0054] As shown in Fig. 3, this manufacturing method includes, in order from the upstream side of a glass article manufacturing line, a melting step P1, a distributing step P2, and a shaping step P3. Note that the molten glass 3 in this embodiment is borosilicate glass. Borosilicate glass contains volatile components.

[0055] In the melting step P1, new molten glass 3 is continuously produced from glass raw materials 2 in a glass melting furnace 4. In the distribution step P2, the molten glass 3 that has flowed from a melting tank 10 of the glass melting furnace 4 into a distribution tank 6 through an outlet passage 5 is distributed to a first flow path 7 and a second flow path 8. Also in the distribution step P2, the surface layer molten glass 3a in the distribution tank 6 is discharged through an outlet 16 to a discharge passage 9. In the forming step P3, a glass article (e.g., a glass plate, a glass tube, a glass fiber, etc.) is formed from the molten glass 3 that has flowed through the first flow path 7 and the second flow path 8.

[0056] Here, between the distribution process P2 and the forming process P3, there may be included a fining process for degassing bubbles contained in the molten glass 3, a stirring process for stirring the molten glass 3 to homogenize it, and an adjustment process for adjusting the temperature (viscosity) of the molten glass 3 and adjusting the flow rate of the molten glass 3 supplied to the forming process P3. [Example]

[0057] The effect of removing extraneous glass according to the first embodiment was confirmed by a numerical simulation. This simulation was a thermal fluid analysis using the finite volume method. The molten glass 3 was assumed to be borosilicate glass, and the values ​​of the specific heat, thermal conductivity, density, and viscosity of the low-expansion borosilicate glass described in Non-Patent Document 1 were used.

[0058] In this simulation, the width W1 inside the distribution tank 6 was set to a fixed value of 2 m, and the width W2 of the upper surface 12a of the outlet shelf 12x was changed to change the value of (W2 / W1) × 100 to six values: 0%, 5%, 7.5%, 10%, 15%, and 20%. Note that a value of 0% for (W2 / W1) × 100 is a comparative example corresponding to a case where the distribution tank 6 is not equipped with a shelf 12. Then, the relationship between each value of (W2 / W1) × 100 and the proportion of extraneous glass discharged from the discharge port 16 out of the extraneous glass inside the distribution tank 6 was calculated.

[0059] The height of the liquid surface 3s of the molten glass 3 in the distribution vessel 6 (dimension H in Figs. 2(a) and 2(b)) was set to 0.5 m. The upper surface 12a of the shelf 12, the opening lower end 16b of the discharge port 16, and the bottom surface 9a of the discharge passage 9 were set to be located 0.1 m below the liquid surface 3s of the molten glass 3. In order to simulate the heat retention effect of the refractory material constituting the distribution vessel 6, the overall heat transfer coefficient was set to 3.5 W / m as a boundary condition. 2 ·K. In the space above the liquid surface 3s of the molten glass 3 in the distribution vessel 6, it was assumed that the temperature would be controlled by combustion gas or an electric heater so that the temperature of the inner wall surface of the distribution vessel 6 would be maintained at 1450°C. Therefore, a radiation heat transfer boundary condition was set for the liquid surface 3s of the molten glass 3, with a radiation boundary temperature of 1450°C and an emissivity of 0.9. The thermal conductivity of the shelf 12 was set to 5.0 W / m·K.

[0060] The temperature and flow rate of the molten glass 3 flowing into the distribution tank 6 from the supply port 13 were 1550°C and 48 tons / day. The flow rates of the molten glass 3 flowing out of the distribution tank 6 into the first flow path 7 and the second flow path 8 were each 20 tons / day. The flow rate of the surface layer molten glass 3a discharged from the distribution tank 6 to the discharge port 16 was 8 tons / day.

[0061] In order to confirm the movement of extraneous glass that is likely to be included in the surface layer molten glass 3a near the side wall 6a away from the supply port 13 in the distribution tank 6, particles representing extraneous glass were placed at the particle tracking start position 17 shown in black in Figure 4. Then, the trajectories of the particles as they moved along the flow of the molten glass 3 toward the first outlet 14, the second outlet 15, or the discharge port 16 were confirmed.

[0062] When the supply port 13 side in the distribution tank 6 is defined as the upstream side and the discharge port 16 side as the downstream side, the particle tracking start position 17 is located downstream of the midpoint between the supply port 13 and the discharge port 16 in the X direction. Furthermore, the particle tracking start position 17 is located within 5 cm from the side wall 6a of the distribution tank 6 and is located in a range excluding the front of the discharge port 16. Furthermore, the particle tracking start position 17 is set to be located 1 mm below the liquid surface 3s of the molten glass 3. At the particle tracking start position 17, approximately 1200 particles (1186 particles to be precise) were arranged in a substantially lattice pattern at intervals of approximately 1 cm.

[0063] FIG. 5 shows the relationship between each value of (W2 / W1) × 100 calculated by this simulation and the discharge rate, which is the proportion of extraneous glass (particles) discharged from the discharge port 16. As can be seen from FIG. 5 , the discharge rate is higher for the examples where the (W2 / W1) × 100 value is 5%, 7.5%, 10%, 15%, and 20%, compared to the comparative example where the (W2 / W1) × 100 value is 0%. Furthermore, it can be seen that the discharge rate increases as the (W2 / W1) × 100 value increases. The discharge rates for the (W2 / W1) × 100 values ​​of 0%, 5%, 7.5%, 10%, 15%, and 20% were 8.9%, 36.6%, 43.1%, 55.1%, 86.3%, and 100%, respectively. The results of this simulation demonstrate that extraneous glass can be efficiently removed from the distribution tank 6 according to the first embodiment.

[0064] Second Embodiment The second embodiment will be described below with reference to Fig. 6. Only the differences between the second embodiment and the first embodiment will be described. The main differences between the second embodiment and the first embodiment are that the distribution tank 6 is hexagonal in plan view, and that the distribution tank 6 does not have a second outlet 15 and is not connected to the second flow path 8.

[0065] The shelves 12 of the second embodiment are provided along three consecutive sides of the six sides of the hexagon formed by the side walls 6a of the distribution tank 6 when the distribution tank 6 is viewed from above. In the second embodiment, the first outlet 14 is the only outlet that the distribution tank 6 has, and the first flow path 7 is the only flow path connected to the distribution tank 6. As a result, in the distribution step P2 of the second embodiment, the molten glass 3 that has flowed into the distribution tank 6 is not substantially distributed, and in the forming step P3, a glass article is formed using only the molten glass 3 that has flowed through the first flow path 7.

[0066] Third Embodiment The third embodiment will be described below with reference to Fig. 7. Only the differences between the first embodiment and the third embodiment will be described. The main differences between the third embodiment and the first embodiment are that the melting tank 10 of the glass-melting furnace 4 has a discharge port 16, and the surface layer molten glass 3a is discharged from the melting tank 10 to a discharge passage 9, and that the melting tank 10 is equipped with a shelf 12. In this embodiment, the melting tank 10 of the glass-melting furnace 4 corresponds to a treatment tank that performs treatments such as producing molten glass 3 and keeping it warm.

[0067] Discharge outlets 16 open near the end of rear wall 10x in the Y direction. There are two discharge outlets 16, one pair on one side and the other side in the Y direction. Each discharge outlet 16 is located above outlet 10a and opens near the liquid surface of molten glass 3 in melting tank 10. In this embodiment, the upper end of the opening of discharge outlet 16 is located above the liquid surface of molten glass 3, and the lower end of the opening is located below the liquid surface of molten glass 3.

[0068] Discharge outlet 16 is disposed farther from supply port 11a of raw material supply device 11 than outlet 10a. Furthermore, discharge outlet 16 is disposed at a position in melting tank 10 that is farthest from supply port 11a in plan view. As a result, when molten glass 3 contains volatile components, surface layer molten glass 3a in melting tank 10 near discharge outlet 16 is more likely to contain extraneous glass.

[0069] The shelf 12 is provided along the inner wall surface of the rear wall 10x of the melting tank 10. In this embodiment, the shelf 12 is provided along the entire length of the rear wall 10x in the Y direction. As a result, the shelf 12 is provided in a continuous range from one of the two discharge ports 16, passing through the outlet port 10a, to the other discharge port 16. The width of the upper surface 12a of the shelf 12 in the X direction (the dimension of the upper surface 12a protruding from the rear wall 10x) is approximately equal to the opening width of the discharge port 16. Of course, this is not limited to this, and as a modified example of this embodiment, the width of the upper surface 12a in the X direction may be longer than the opening width of the discharge port 16. Above the upper surface 12a of the shelf 12, a flow is generated that guides the surface layer molten glass 3a toward the discharge port 16.

[0070] Upper surface 12a of shelf 12 is located below the liquid level of molten glass 3 in melting tank 10. In other words, shelf 12 is entirely submerged in molten glass 3 in melting tank 10. Upper surface 12a of shelf 12 is located above outlet 10a. As a result, shelf 12 forms the roof of outlet 10a.

[0071] There are two pairs of discharge passages 9, one on one side in the Y direction and the other on the other side. The upstream end of each discharge passage 9 is connected to the melting tank 10. As shown by arrows D5 and D6 in FIG. 7 , the two discharge passages 9 circulate the surface layer molten glass 3a that has flowed from the melting tank 10 into the discharge passages 9 through discharge ports 16.

[0072] <Other variations> The following modifications can also be applied to the above-described embodiment. The manner in which the shelf 12 is provided in the distribution tank 6 or the melting tank 10 is not limited to the above-described embodiments. The shelf 12 only needs to be provided within the range in which the discharge port 16 is present (within the range of the opening width of the discharge port 16) when the distribution tank 6 or the melting tank 10 is viewed from above.

[0073] Regarding the height position of the upper surface 12a of the shelf 12, in each of the above embodiments, the upper surface 12a of the shelf 12 is at the same height position as the lower end 16b of the opening of the discharge outlet 16 and the bottom surface 9a of the discharge passage 9, but this is not limited to this. The upper surface 12a of the shelf 12 may also be located lower than the lower end 16b of the opening of the discharge outlet 16 and the bottom surface 9a of the discharge passage 9.

[0074] The configuration of the shelf 12 is not limited to the above-described embodiments. The shelf 12 may be a plate-like member protruding from the side wall 6a of the distributing tank 6 or the rear wall 10x of the melting tank 10. However, from the viewpoint of ensuring the strength of the shelf 12, it is preferable to adopt the configuration of the above-described embodiments.

[0075] Regarding the arrangement of the discharge outlet 16, in each of the above embodiments, the discharge outlet 16 is arranged farther from the supply port (the supply port 13 in the first and second embodiments, the supply port 11a in the third embodiment) than the outlet (the first and second outlets 14, 15 in the first embodiment, the first outlet 14 in the second embodiment, and the outlet 10a in the third embodiment), but this is not limited thereto. Unlike each of the above embodiments, the discharge outlet 16 may be arranged closer to the supply ports 13, 11a than the outlets 14, 15, 10a. However, in this case, it is necessary to provide a shelf 12 in a continuous range from the discharge outlet 16 to the outlets 14, 15, 10a. [Explanation of symbols]

[0076] 1. Glass product manufacturing equipment 2. Glass raw materials 3 Molten Glass 3a Surface molten glass 6 Distribution tank (treatment tank) 6a Sidewall 10. Melting tank (processing tank) 10a Outlet 10x Rear Sidewall 11a Supply Port 12 sheds 12a above 12x Outlet Shed 13 Supply Port 14 First-class export 15 Secondary Exit 16 discharge outlets 16a Opening at the top 16b Opening at the lower end P3 Molding Engineering W1 W2 pieces

Claims

1. a treatment tank for treating molten glass; The treatment tank a supply port for supplying molten glass or glass raw material into the treatment tank; an outlet for allowing the molten glass to flow out of the treatment tank and communicating with a manufacturing facility downstream of the treatment tank; a discharge port disposed above the outlet for discharging the surface layer molten glass in the treatment tank to the outside of the tank, the discharge port opening on a side wall of the treatment tank; An apparatus for manufacturing a glass article, comprising: When the treatment tank is viewed from above, the outlet and the discharge port are arranged so as not to overlap each other, and the discharge port is arranged at a greater distance from the supply port than the outlet, The treatment tank further includes a shelf provided along an inner wall surface of the side wall, an upper surface of the shelf is located above the outflow port and below the upper end of the opening of the discharge port; A glass article manufacturing apparatus, characterized in that the shelf is provided at least in the range where the discharge outlet is present when the processing tank is viewed from above.

2. 2. The glass article manufacturing apparatus according to claim 1, wherein the upper surface of the shelf is located at the same height as or lower than the lower end of the opening of the discharge outlet.

3. The outlet opens on a side wall of the treatment tank, 3. The glass article manufacturing apparatus according to claim 1, wherein the shelf is provided in a range that is continuous from the discharge port to the outflow port when the treatment tank is viewed from above.

4. 4. The apparatus for manufacturing a glass article according to claim 3, wherein the treatment tank has a plurality of outlets.

5. 5. The glass article manufacturing apparatus according to claim 4, wherein the supply port and the discharge port are disposed opposite to each other when the treatment tank is viewed from above.

6. When the treatment tank is viewed from above, The glass article manufacturing apparatus of claim 5, characterized in that the portion of the shelf located within the range where the outlet is present is designated as an outlet shelf, and the direction in which molten glass flows out of the outlet is designated as the outflow direction, and the width of the upper surface of the outlet shelf along the outflow direction is 10% or more of the width along the outflow direction in the treatment tank.

7. When the treatment tank is viewed from above, 3. The glass article manufacturing apparatus according to claim 1, wherein the direction in which the surface layer molten glass is discharged from the discharge port is defined as a discharge direction, and the opening width of the discharge port gradually increases from the downstream side to the upstream side in the discharge direction of the surface layer molten glass.

8. a treatment tank for treating molten glass; The treatment tank a supply port for supplying molten glass or glass raw material into the treatment tank; an outlet for allowing the molten glass to flow out of the treatment tank and communicating with a manufacturing facility downstream of the treatment tank; a discharge port disposed above the outflow port and configured to discharge the surface layer molten glass in the treatment tank to the outside of the tank; An apparatus for manufacturing a glass article, comprising: When the treatment tank is viewed from above, the outflow port and the discharge port open at different positions on a side wall of the treatment tank, The treatment tank further includes a shelf provided along an inner wall surface of the side wall, an upper surface of the shelf is located above the outflow port and below the upper end of the opening of the discharge port; A glass article manufacturing apparatus, characterized in that, when the processing tank is viewed from above, the shelf is provided in a continuous range from the discharge outlet to the outflow outlet.

9. A method for manufacturing a glass article, comprising a forming step of forming a glass article from molten glass discharged from the outlet of the treatment tank using the glass article manufacturing apparatus according to any one of claims 1 to 2 and 8.

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