TWI835935B - How to make glass items - Google Patents

Abstract

The method of manufacturing a glass article includes: a step of heating and melting glass raw materials in the melting tank 1 to generate molten glass GM; a step of transporting the molten glass GM flowing out from the outflow port 1a of the melting tank 1 using a transport pipe 10; and a step of transporting the molten glass GM. In a state where the tubular portion 7 of the clarification tank 2 is filled with the molten glass GM conveyed through the pipe 10, a clarification process is performed on the molten glass GM. The transfer pipe 10 includes an upstream end portion 10 a connected to the melting tank 1 and a downstream end portion 10 b connected to the tubular portion 7 . The conveying pipe 10 is connected to the tubular portion 7 so that the top portion 11 a of the inner surface of the downstream end portion 10 b coincides with the top portion 7 b of the inner surface of the tubular portion 7 .

Description

Method for manufacturing glass articles

The present invention relates to a method of manufacturing plate glass and other glass articles.

As is well known, plate glass is used in flat panel displays such as liquid crystal displays (LCDs) and organic electroluminescence (EL) displays. As a method for manufacturing plate glass, various molding methods such as a down draw method and a float method can be used.

For example, the plate glass is transformed into a plate shape through each step such as a melting step, a clarification step, a homogenization step, and a forming step. Patent Document 1 discloses a manufacturing device that includes a melting tank, a clarification tank, a stirring tank, a forming device, and a glass supply pipe connecting these components to each other as a manufacturing device for executing each of the steps. The clarifier or glass supply pipe contains platinum material (platinum or platinum alloy) with a high melting point and excellent corrosion resistance. Moreover, the clarification tank has a vent part (vent pipe) which discharges the gas generated from the molten glass. [Prior art documents] [Patent Document]

Patent document 1: Japanese Patent Publication No. 2014-028734

[Problem to be solved by the invention] Depending on the structure of the clarification tank, molten glass may remain and the gas generated from the molten glass may accumulate in the clarification tank without being discharged from the exhaust part. When a gas accumulation portion is formed in the clarification tank, the platinum material constituting the clarification tank is oxidized, and platinum oxide is mixed into the molten glass. As a result, abnormalities such as protruding particles may occur in the produced plate glass, resulting in reduced quality or defective products.

The reason why the gas accumulation portion is generated will be described with reference to FIG. 8 . The clarification tank C includes a tubular portion Ca and a flange portion F1 provided at an upstream end portion of the tubular portion Ca. The tubular part Ca has a top Cb and a bottom Cc on its inner surface. The flange portion F1 is configured in a disk shape and has a circular opening O1. The diameter of the opening O1 is set smaller than the inner diameter of the tubular part Ca. The opening O1 penetrates the flange part F1 so that its lower end coincides with the bottom Cc of the tubular part Ca. In a portion above the opening O1, the wall portion of the flange portion F1 blocks the end portion of the tubular portion Ca. The inside of the clarification tank C is filled with molten glass GM. That is, the liquid level of the molten glass GM is in contact with the top Cb of the tubular portion Ca.

A delivery pipe P1 is connected to the upstream end of the clarification tank C. The delivery pipe P1 has a flange F2 and a circular opening O2 at its downstream end. The delivery pipe P1 is connected to the clarification tank C in a state where the flange F2 contacts the flange F1 of the clarification tank C and the opening O2 overlaps the opening O1 of the clarification tank C.

In the said structure, molten glass GM is easy to accumulate in the area between the top Cb of the upstream end part of the clarification tank C, and the wall part of the flange part F1. If the gas generated from the molten glass GM floats and reaches the area where the molten glass GM is retained, the gas accumulation portion GA will be generated due to gas stagnation.

The present invention is made in view of the above situation, and its technical problem is to prevent the formation of gas accumulation inside the clarification tank. [Means for solving the problem]

The present invention is used to solve the above-mentioned problem, and comprises: a step of heating and melting glass raw materials in a melting tank to generate molten glass; a step of transporting the molten glass flowing out from the outflow port of the melting tank by using a conveying pipe; and a step of subjecting the molten glass to clarification treatment when the molten glass transported from the conveying pipe fills the tubular portion of the clarification tank, and in the manufacturing method of the glass article: the conveying pipe comprises an upstream side end portion connected to the melting tank, and a downstream side end portion connected to the tubular portion, and the conveying pipe is connected to the tubular portion in a manner that the top of the inner surface of the downstream side end portion is consistent with the top of the inner surface of the tubular portion.

According to this structure, the top of the inner surface of the delivery pipe is made to coincide with the top of the inner surface of the tubular portion of the clarification tank, so that the molten glass flowing from the delivery pipe into the clarification tank can flow along the top of the inner surface of the delivery pipe and the top of the inner surface of the tubular portion without stagnation. Therefore, the gas generated from the molten glass can float and move in the clarification tank along with the flow of the molten glass. Therefore, the generation of a gas accumulation part can be prevented.

The delivery pipe may be connected to the melting tank in such a manner that the top of the inner surface of the upstream side end portion coincides with the top of the inner surface of the outflow port, and the bottom of the inner surface of the upstream side end portion coincides with the bottom of the inner surface of the outflow port. In this way, the molten glass can flow from the melting tank to the delivery pipe without stagnation.

The conveying pipe may be connected to the tubular part so that the bottom of the inner surface of the downstream end coincides with the bottom of the inner surface of the tubular part. Here, when the inner diameter of the tubular portion of the clarification tank is larger than the inner diameter of the delivery pipe, the bottom of the inner surface of the tubular portion does not coincide with the bottom of the inner surface of the downstream end portion, so the inner surface of the tubular portion Molten glass tends to accumulate around the bottom. For example, by setting the inner diameter of the delivery pipe to be substantially the same as the inner diameter of the tubular portion, and making the bottom of the inner surface of the tubular portion coincide with the bottom of the inner surface of the downstream end portion, it is possible to prevent the tubular portion from being Molten glass remains on the bottom perimeter of the inner surface.

The delivery pipe may have an enlarged diameter portion whose inner diameter gradually increases toward the downstream end. Thereby, even when the inner diameter of the tubular part of the clarification tank is larger than the inner diameter of the conveying pipe, the conveying pipe can align the bottom of the inner surface of the downstream end with the bottom of the inner surface of the tubular part, thereby preventing Molten glass remains around the bottom of the inner surface of the tubular part. Moreover, in the existing equipment in which the diameter of the outflow port is different from the inner diameter of the tubular part of the clarification tank, it is possible to prevent the gas accumulation part from being generated inside the clarification tank simply by changing the delivery pipe.

The delivery pipe is configured as a straight pipe, and the delivery pipe can be connected to the tubular portion in a manner that the bottom of the inner surface of the downstream side end portion is higher than the bottom of the inner surface of the tubular portion. Here, the outer surface of the delivery pipe is supported by a refractory. If the delivery pipe has an expanded diameter portion as described above, a gap is easily generated between the refractory and the delivery pipe due to the difference in thermal expansion between the delivery pipe and the refractory. Therefore, due to deformation or damage of the delivery pipe, there is the following concern, namely, the period (life) during which the delivery pipe can be used is shortened. If a delivery pipe configured as a straight pipe is adopted, the outer surface of the delivery pipe can be easily supported, and the period during which the delivery pipe can be used can be maintained. In addition, the increase in the manufacturing cost of the delivery pipe can also be suppressed. Furthermore, in the conventional equipment in which the diameter of the outflow port is different from the inner diameter of the tubular portion of the clarification tank, it is possible to prevent the generation of a gas accumulation portion inside the clarification tank simply by changing the delivery pipe.

This method may include the step of heating the transport pipe and the tubular portion in a state of being separated. By heating the transport pipe and the tubular part of the clarification tank in a separated state, the transport pipe and the tubular part of the clarification tank can be expanded in advance. By connecting the transfer pipe and the tubular portion of the clarification tank after expanding, the tubular portion of the clarification tank and the transfer pipe can be prevented from expanding during the clarification process, thereby preventing deformation due to thermal stress. [Effects of the invention]

According to the present invention, it is possible to prevent gas accumulation inside the clarification tank.

Hereinafter, modes for implementing the present invention will be described with reference to the drawings. 1 to 5 illustrate a first embodiment of the manufacturing method and manufacturing apparatus of a glass article of the present invention.

As shown in FIG1 , the manufacturing device of the glass article of the present embodiment includes, from the upstream side, a melting tank 1, a clarification tank 2, a homogenization tank (stirring tank) 3, a pot 4, a forming body 5, and glass supply pipes 6a to 6d connecting the components 1 to 5. In addition, the manufacturing device includes a slow cooling furnace (not shown) for slow cooling the plate glass GR (glass article) formed by the forming body 5, and a cutting device (not shown) for cutting the plate glass GR after slow cooling.

The melting tank 1 is a container for performing a melting step of heating and melting the input glass raw material to obtain molten glass GM. The melting tank 1 is connected to the clarification tank 2 via the glass supply pipe 6a. As shown in FIG. 2, the melting tank 1 has the outflow port 1a which supplies molten glass GM to the glass supply line 6a. The outlet 1a is a circular hole penetrating the wall portion 1b.

The clarification tank 2 performs a clarification step (clarification treatment) of defoaming the molten glass GM by the action of a clarifier or the like while conveying the molten glass GM. The clarification tank 2 is connected to the homogenization tank 3 by a glass supply pipe 6b. The clarification tank 2 is formed into a tubular shape by a platinum material (platinum or a platinum alloy). As shown in FIG. 2 , the clarification tank 2 includes a tubular portion 7, and flange portions 8a and 8b provided at both ends of the tubular portion 7.

2 , the flow direction of molten glass GM is indicated by symbol F. Hereinafter, when describing the position of each component, the terms “upstream side” and “downstream side” are used based on the flow direction F of molten glass GM.

The tubular portion 7 is formed into a circular tube shape, but is not limited to this structure. Ideally, the inner diameter of the tubular portion 7 is 100 mm or more and 300 mm or less. It is desirable to set the wall thickness of the tubular portion 7 to 0.3 mm or more and 3 mm or less. It is desirable to set the length of the tubular portion 7 to not less than 300 mm and not more than 10,000 mm. The said size is not limited to the said range, It is set suitably according to the type, temperature, the scale of a manufacturing apparatus, etc. of molten glass GM.

The clarification tank 2 has an exhaust part 7a for discharging the gas generated in the molten glass GM at the top of the tubular part 7. Moreover, the clarification tank 2 may have the partition plate (baffle) for changing the flow direction of the molten glass GM inside the tubular part 7.

As shown in FIGS. 1 and 2 , the liquid level GS of the molten glass GM in the melting tank 1 is set above the top (vertex) 7 b of the inner surface of the tubular portion 7 or at the same position as the top 7 b. The height difference H is set to 0 mm or more and 200 mm or less, but is not limited to the above range. With this setting, the entire internal space of the tubular portion 7 is filled with the molten glass GM flowing in from the melting tank 1 . That is, inside the tubular portion 7 , the upper inner surface of the tubular portion 7 is not separated from the molten glass GM, but the entire inner surface is in contact with the molten glass GM (see FIG. 2 ). In this way, since the entire inner surface of the tubular portion 7 is in contact with the molten glass GM and no gas phase space is formed in the tubular portion 7 , oxidation of the inner surface of the tubular portion 7 can be prevented. Furthermore, the positions of all the transfer pipes constituting each of the glass supply lines 6a to 6d are also set lower than the liquid level GS of the molten glass GM.

The flanges 8a and 8b of the clarification tank 2 are circular, but are not limited to this shape. A plate-shaped protrusion for supporting an electrode may be formed on the upper part of the flanges 8a and 8b. The flanges 8a and 8b are connected to a power supply device (not shown). The clarification tank 2 heats the molten glass GM flowing inside the tubular portion 7 by resistance heating (Joule heat) generated by causing a current to flow into the tubular portion 7 through each flange 8a and 8b.

The flange 8a and the flange 8b of the clarification tank 2 include: a first flange 8a provided at the upstream side end 2a of the tubular portion 7; and a second flange 8b provided at the downstream side end 2b of the clarification tank 2 (tubular portion 7). The first flange 8a has a first opening 9a for allowing molten glass GM to flow into the tubular portion 7. The second flange 8b has a second opening 9b for allowing molten glass GM to flow out of the tubular portion 7. The first opening 9a and the second opening 9b are configured in a circular shape. The diameter of each opening 9a and the opening 9b is set to be smaller than the inner diameter of the tubular portion 7.

As shown in FIGS. 2 and 3 , the first opening 9 a is formed corresponding to the upper part of the tubular part 7 . That is, the uppermost portion (hereinafter referred to as the "upper end") 9aU of the first opening 9a coincides with the top 7b of the inner surface of the tubular portion 7 . Similarly, the second opening 9 b is formed corresponding to the upper part of the tubular part 7 . The upper end portion 9bU of the second opening portion 9b coincides with the top portion 7b of the inner surface of the tubular portion 7.

The glass supply pipe 6a connecting the melting tank 1 and the clarification tank 2 includes a delivery pipe made of a platinum material (platinum or a platinum alloy). The delivery pipe 10 includes a tubular portion 11, and flanges 12a and 12b provided at both ends 10a and 10b of the delivery pipe 10. Each flange 12a and 12b includes a first flange 12a formed at the upstream end 10a of the delivery pipe 10, and a second flange 12b formed at the downstream end 10b.

The inner diameter of the tubular portion 11 of the delivery pipe 10 is preferably 100 mm or more and 300 mm or less. The wall thickness of the tubular portion 11 is preferably 0.3 mm or more and 3 mm or less. These dimensions are not limited to the ranges described above, and are appropriately set depending on the type, temperature, production equipment scale, etc. of the molten glass GM. In this embodiment, the inner diameter D of the tubular part 11 is set smaller than the inner diameter of the tubular part 7 of the clarification tank 2. The tubular portion 11 is inclined upward from the melting tank 1 toward the clarification tank 2 . The inclination angle of the tubular portion 11 with respect to the horizontal direction is set to, for example, 3° or more and 30° or less.

The first flange portion 12 a of the transport pipe 10 is in contact with the wall portion 1 b of the melting tank 1 , and the second flange portion 12 b is in opposing contact with the first flange portion 8 a of the clarification tank 2 . Each flange part 12a and the flange part 12b has an opening part 13a and an opening part 13b. Each of the openings 13a and 13b is configured in an oblong shape in the up-down direction. The length DL of the major axis of each opening 13 a and 13 b is substantially equal to the inner diameter D of the tubular part 11 . Here, “substantially equal” means that the length DL of the long axis is not less than 90% and not more than 110% of the inner diameter D of the tubular portion 11 .

The opening 13a of the first flange portion 12a overlaps the outlet 1a of the melting tank 1. The opening area of the opening 13a is set smaller than the opening area of the outflow port 1a. The length DL of the major axis of the opening 13a of the first flange portion 12a is substantially equal to the diameter of the outflow port 1a. Here, "substantially equal" means that the length DL of the long axis is 90% or more and 110% or less of the diameter of the outflow port 1a.

As shown in FIG. 2 , the top 11 a of the inner surface of the upstream end 10 a of the transport pipe 10 coincides with the top of the inner surface of the outflow port 1 a of the melting tank 1 . That is, the upper end 13aU of the opening 13a of the delivery pipe 10 coincides with the upper end 1aU of the outflow port 1a. The bottom 11 b of the inner surface of the upstream end 10 a of the transport pipe 10 coincides with the bottom of the outflow port 1 a. That is, the lower end 13aD of the opening 13a of the delivery pipe 10 coincides with the lower end 1aD of the outflow port 1a.

The opening 13b of the second flange 12b overlaps with the first opening 9a of the first flange 8a of the clarification tank 2. The opening area of the opening 13b is set to be smaller than the opening area of the first opening 9a of the clarification tank 2. The length DL of the major axis of the opening 13b is substantially equal to the diameter of the first opening 9a of the clarification tank 2. That is, the length DL of the major axis is set to be 90% or more and 110% or less of the diameter of the first opening 9a.

The top 11a of the inner surface of the downstream end portion 10b of the delivery pipe 10 coincides with the top 7b of the inner surface of the clarification tank 2. That is, the upper end 13bU of the opening 13b of the downstream end portion 10b of the delivery pipe 10 coincides with the upper end 9aU of the first opening 9a of the clarification tank 2. Furthermore, the lower end 13bD of the opening 13b of the delivery pipe 10 coincides with the lower end 9aD of the first opening 9a of the clarification tank 2.

The glass supply line 6b connecting the clarification tank 2 and the homogenization tank 3 includes a delivery pipe containing platinum material (platinum or platinum alloy). The transport pipe 14 is configured in a straight tube shape and is connected to the downstream end 2b of the clarification tank 2 . As shown in FIG. 2 , the delivery pipe 14 has a tubular portion 15 and flange portions 16 a , 16 b , and openings 17 a and 17 b provided at both ends 14 a and 14 b of the delivery pipe 14 .

The inner diameter of the tubular portion 15 of the delivery pipe 14 is preferably not less than 100 mm and not more than 300 mm. The wall thickness of the tubular portion 15 is preferably 0.3 mm or more and 3 mm or less. These dimensions are not limited to the ranges described above, and are appropriately set depending on the type, temperature, production equipment scale, etc. of the molten glass GM. In this embodiment, the inner diameter of the tubular part 15 is set smaller than the inner diameter of the tubular part 7 of the clarification tank 2.

Each flange 16a, 16b is formed into a disk shape. Each opening 17a, 17b is formed into a circular shape. The opening area of the opening 17a, 17b is substantially equal to the opening area of the second opening 9b of the second flange 8b of the clarification tank 2. According to the above configuration, the entire circumference of the opening 17a of the upstream side end 14a of the delivery pipe 14 is arranged in a manner consistent with the entire circumference of the second opening 9b of the clarification tank 2.

Each flange 12a, flange 12b, flange 16a, flange 16b of each delivery pipe 10, delivery pipe 14 is connected to a power supply device (not shown). In each glass supply pipe 6a, glass supply pipe 6b, similarly to the clarification tank 2, the molten glass GM flowing inside the delivery pipe 10, delivery pipe 14 is heated by resistance heating (Joule heat) generated by causing current to flow into each tubular portion 11, tubular portion 15 through each flange 12a, flange 12b, flange 16a, flange 16b (same for other glass supply pipes 6c, glass supply pipe 6d).

The homogenization tank 3 is a container made of a platinum material for performing a step (homogenization step) of stirring and homogenizing the molten glass GM that has been subjected to a clarification process. The homogenization tank 3 includes a stirrer 3a having stirring blades. The homogenization tank 3 is connected to the tank 4 via the glass supply line 6c. The glass supply line 6c, like the glass supply line 6a and the glass supply line 6b, includes a delivery pipe made of platinum material (platinum or platinum alloy).

The tank 4 is a container for performing a state adjustment step of adjusting the molten glass GM to a state suitable for forming. The tank 4 is exemplified as a volumetric portion for adjusting the viscosity and flow rate of the molten glass GM. The tank 4 is connected to the forming body 5 via a glass supply line 6d. The glass supply line 6d includes a delivery pipe containing a platinum material (platinum or a platinum alloy) similarly to the glass supply lines 6a to 6c.

The forming body 5 forms the molten glass GM into a desired shape. In the present embodiment, the forming body 5 forms the molten glass GM into a plate shape by an overflow down draw method. Specifically, the cross-sectional shape of the forming body 5 (the cross-sectional shape perpendicular to the paper surface of FIG. 1 ) is substantially wedge-shaped, and an overflow groove (not shown) is formed on the upper part of the forming body 5.

The forming body 5 makes the molten glass GM overflow from the overflow trough and flow down along the side wall surfaces (side surfaces located on the front and back sides of the paper surface) on both sides of the forming body 5. The forming body 5 makes the molten glass GM that has flowed down merge at the lower top of the side wall surface. Thereby, the strip-shaped plate glass GR is formed. Furthermore, the forming body 5 may also be a forming body that performs other down-drawing methods such as the slot down draw method. Furthermore, a forming device using the float process may also be provided instead of the forming body 5.

The sheet glass GR obtained in this manner has a thickness of, for example, 0.01 mm to 10 mm, and is used for substrates or protective covers of flat panel displays such as liquid crystal displays and organic EL displays, organic EL lighting, solar cells, and the like. The glass article of the present invention is not limited to plate glass GR, but includes those having various shapes such as glass tubes. For example, when forming a glass tube, a forming device using the Danner method is provided instead of the formed body 5 .

As the material of the plate glass GR, silicate glass and silica glass can be used, preferably borosilicate glass, sodium calcium glass, aluminum silicate glass, chemically strengthened glass, and alkali-free glass is the most preferable. Here, the so-called alkali-free glass refers to glass that does not substantially contain alkali components (alkali metal oxides), specifically, glass in which the weight ratio of alkali components is 3000 ppm or less. The weight ratio of alkali components in the present invention is preferably 1000 ppm or less, more preferably 500 ppm or less, and most preferably 300 ppm or less.

The following is a description of a method for manufacturing a glass article (plate glass GR) by using the manufacturing apparatus of the above structure. As shown in FIG4 , the method mainly includes: a preheating step S1, an assembly step S2, a melting step S3, a molten glass supply step S4, a forming step S5, a slow cooling step S6, and a cutting step S7.

In the preheating step S1, the temperature of each of the constituent elements 1 to 5 and 6a to 6d of the manufacturing apparatus is increased in a state where these constituent elements are individually separated. As an example, FIG. 5 shows a state in which the transport pipe 10 and the clarification tank 2 are separated. Furthermore, in the preheating step S1, the outlet 1a of the melting tank 1 is blocked by a blocking member. By the preheating step S1, each of the component elements 1 to 5 and 6a to 6d is heated to a predetermined temperature. By the above-mentioned heating, the platinum material portions in each of the constituent elements 1 to 5 and 6a to 6d expand. For example, as shown by the two-dot chain line in FIG. 5, the tubular part 7 of the clarification tank 2 and the tubular part 11 of the conveyance pipe 10 expand in the longitudinal direction.

In the assembly step S2, the separated components 1 to 5 and 6a to 6d are connected to each other to assemble the manufacturing device. For example, the upstream end 10a of the transfer pipe 10 is connected to the outflow port 1a of the melting tank 1. Specifically, the first flange portion 12a of the transport pipe 10 is brought into contact with the wall portion 1b of the melting tank 1, and the opening portion 13a is overlapped with the outflow port 1a.

Next, the downstream end portion 10b of the delivery pipe 10 is connected to the upstream end portion 2a of the clarification tank 2. That is, the second flange portion 12b of the delivery pipe 10 and the first flange portion 8a of the clarification tank 2 are opposed to each other and are in contact with each other. At this time, the flange portions 8a and 12b are overlapped so that the upper end portion 9aU of the first opening portion 9a of the clarification tank 2 and the upper end portion 13bU of the opening portion 13b of the delivery pipe 10 are aligned.

Thereafter, the transport pipe 14 and the clarification tank 2 are connected. That is, the flange part 16a of the conveyance pipe 14 and the 2nd flange part 8b of the clarification tank 2 are made to oppose and they contact each other. At this time, each flange part 8b and the flange part 16a are overlapped so that the opening part 17a of the conveyance pipe 14 may match the 2nd opening part 9b of the clarification tank 2.

Furthermore, the manufacturing apparatus is assembled by connecting the homogenization tank 3, the tank 4, the molded body 5, the glass supply line 6c, and the glass supply line 6d.

In the melting step S3, the glass raw material supplied into the melting tank 1 is heated to generate molten glass GM. Furthermore, in order to shorten the start-up period of the manufacturing device, the molten glass GM may be generated in advance in the melting tank 1 before the assembly step S2.

In the molten glass supply step S4, the molten glass GM in the melting tank 1 is sequentially transported to the clarification tank 2, the homogenization tank 3, the tank 4, and the formed body 5 via the respective glass supply lines 6a to 6d. . In the molten glass supply step S4, when the molten glass GM circulates in the tubular portion 7 of the clarification tank 2, gas (bubbles) is generated from the molten glass GM by the action of the clarifier blended in the glass raw material. This gas is discharged to the outside from the exhaust part 7a of the clarification tank 2 (clarification step). Moreover, in the homogenization tank 3, the molten glass GM is stirred and homogenized (homogenization step). When the molten glass GM passes through the tank 4 and the glass supply line 6d, its state (such as viscosity or flow rate) is adjusted (state adjustment step).

In the forming step S5, the molten glass GM is supplied to the formed body 5 after passing through the molten glass supplying step S4. The formed body 5 causes the molten glass GM to overflow from the overflow tank and flow downward along its side wall. In the formed body 5, the molten glass GM that has flowed down is fused at the lower top, thereby forming a strip-shaped plate glass GR.

Thereafter, the strip-shaped plate glass GR is cooled by the slow cooling furnace in the slow cooling step S6, and is cut by the cutting device in the cutting step S7. Thus, a plate glass (glass article) of a predetermined size is cut out from the strip-shaped plate glass GR. Alternatively, after removing both ends of the plate glass GR in the width direction in the cutting step S7, the strip-shaped plate glass GR may be wound into a roll to obtain a glass roll as a glass article (winding step).

According to the manufacturing method of the glass article of the present embodiment described above, in the state where the delivery pipe 10 and the clarification tank 2 are connected, the top 11a (the upper end 13bU of the opening 13b) of the inner surface of the downstream side end 10b of the delivery pipe 10 is made to coincide with the top 7b (the upper end 9aU of the first opening 9a) of the inner surface of the upstream side end 2a of the clarification tank 2, whereby the molten glass GM flowing from the delivery pipe 10 into the clarification tank 2 can flow without stagnation along the top 11a of the delivery pipe 10 and the top 7b of the clarification tank 2. Therefore, the gas generated from the molten glass GM moves in the clarification tank 2 without generating a gas accumulation portion along with the flow of the molten glass GM, and is reliably discharged from the exhaust portion 7a. Moreover, even if gas is generated from molten glass GM around the bottom 7c of the clarification tank 2, since the gas floats, it moves in the clarification tank 2 along with the flow of the molten glass GM, and is surely exhausted from the exhaust part 7a.

Here, in the manufacturing apparatus of 1st Embodiment, molten glass GM tends to accumulate around the bottom 7c of the clarification tank 2, especially around the bottom 7c of the upstream end part 2a of the clarification tank 2, and molten glass GM tends to accumulate. In this case, there is a concern that the retained molten glass GM may deteriorate. From the viewpoint of preventing such concerns, it is preferable to adopt the second embodiment or the third embodiment described below.

FIG. 6 shows a part of the manufacturing apparatus of the second embodiment. In the manufacturing apparatus of this embodiment, the tubular portion 11 of the conveyance pipe 10 includes a straight first tubular portion 11A and a tapered second tubular portion 11B. The first tubular portion 11A is formed on the upstream end 10 a side of the transport pipe 10 and is connected to the melting tank 1 . The second tubular portion 11B is formed on the downstream end portion 10b side of the transport pipe 10 and is connected to the clarification tank 2 .

The second tubular portion 11B includes an expanded portion whose inner diameter gradually increases from the middle portion of the delivery pipe 10 toward the downstream end portion 10b. According to the above configuration, the opening portion 13b of the downstream end portion 10b of the delivery pipe 10 is formed into a circular shape.

The inner diameter of the second tubular portion 11B of the downstream end portion 10b of the delivery pipe 10 is substantially equal to the inner diameter of the tubular portion 7 of the clarification tank 2. That is, the diameter of the opening portion 13b of the downstream end portion 10b of the delivery pipe 10 is set to be 90% or more and 110% or less of the inner diameter of the tubular portion 7 of the clarification tank 2. Moreover, the diameter of the first opening portion 9a formed in the first flange portion 8a of the clarification tank 2 is substantially equal to the inner diameter of the tubular portion 7. According to the above configuration, the bottom 13bD of the opening portion 13b of the second tubular portion 11B of the delivery pipe 10 coincides with the bottom 9aD of the first opening portion 9a of the upstream end portion 2a of the clarification tank 2. Thereby, the molten glass GM which flows into the clarification tank 2 from the conveying pipe 10 flows without stagnation not only along the top 11a of the conveying pipe 10 and the top 7b of the clarification tank 2, but also flows without stagnation along the bottom 11b of the conveying pipe 10 and the bottom 7c of the clarification tank 2.

FIG. 7 shows a part of the manufacturing apparatus of the third embodiment. In the second embodiment, the second tubular portion 11B of the delivery pipe 10 is configured as an enlarged diameter portion. However, in the present embodiment, the second tubular portion 11B of the delivery pipe 10 is configured as a straight tube with a fixed inner diameter.

The opening 13b of the downstream end 10b of the delivery pipe 10 (second tubular portion 11B) is formed in a long ellipse in the vertical direction similarly to the first embodiment. In the third embodiment, unlike the first embodiment, the length DL of the long axis of the opening 13b is substantially equal to the inner diameter of the tubular portion 7 of the clarification tank 2. Therefore, in this embodiment, the bottom 13bD of the opening 13b of the second tubular portion 11B of the delivery pipe 10 also coincides with the bottom 9aD of the first opening 9a of the upstream end 2a of the clarification tank 2. Therefore, the molten glass GM flowing from the conveying pipe 10 into the clarification tank 2 flows without stagnation not only along the top 11a of the conveying pipe 10 and the top 7b of the clarification tank 2 but also along the bottom 11b of the conveying pipe 10 and the bottom 7c of the clarification tank 2.

Furthermore, the present invention is not limited to the structure of the above-mentioned embodiment, nor is it limited to the above-mentioned effects. The present invention can be modified in various ways without departing from the scope of the present invention.

In the second embodiment, the expanded diameter portion (second tubular portion 11B) is provided in the range from the midway portion of the conveying pipe 10 to the downstream end portion 10b, but the present invention is not limited to this. structure. For example, the tubular portion 11 may be configured as an enlarged diameter portion over the entire length from the upstream end 10 a of the transport pipe 10 to the downstream end 10 b.

1: Melting tank (component) 1a: Outlet of the melting tank (outlet) 1aD: The lower end of the outflow port 1aU: The upper end (top) of the outflow port 1b: Wall 2: Clarification tank (component) 2a: Upstream end of the tubular part (upstream end of the clarification tank) 2b: Downstream end of clarification tank (tubular part) 3: Homogenization tank (stirring tank, components) 3a: Blender 4: Tank (component) 5: Molded body (component) 6a, 6b, 6c, 6d: Glass supply pipe (component) 7: Tubular part of the clarification tank (tubular part) 7a:Exhaust part 7b: The top of the inner surface of the tubular part (the apex of the inner surface of the tubular part, the top of the clarification tank) 7c: Bottom of the clarification tank (bottom of the upstream end of the clarification tank) 8a: Flange part of the clarification tank (flange part, first flange part) 8b: Flange part of the clarification tank (flange part, second flange part) 9a: First opening (opening) 9aD: Lower end of the first opening (bottom of the first opening) 9aU: The upper end of the first opening 9b: Second opening (opening) 9bU: The upper end of the second opening 10, 14, P1: conveyor pipe 10a: Upstream end of the delivery pipe (upstream end) 10b: Downstream end of the conveying pipe (downstream end) 11, 15, Ca: tubular part 11a: The top of the inner surface of the conveying pipe (the top of the inner surface of the downstream end, the top of the conveying pipe) 11A: First tubular part 11b: Bottom of the inner surface of the upstream end (bottom of the delivery pipe) 11B: Second tubular part (enlarged diameter part) 12a: Flange part (first flange part) 12b: Flange part (second flange part) 13a: Opening part (opening part of the first flange part, opening part of the delivery pipe) 13aD: Lower end of the opening of the delivery pipe 13aU: The upper end of the opening of the delivery pipe 13b: Opening part (the opening part of the second flange part, the opening part of the downstream end part of the conveying pipe, the opening part of the second tubular part of the conveying pipe) 13bD: Lower end of the opening of the delivery pipe (bottom of the opening of the second tubular part) 13bU: The upper end of the opening of the downstream end of the conveying pipe (the upper end of the opening of the conveying pipe) 14a: End (upstream end of the delivery pipe) 14b: end 16a: Flange part (flange part of the delivery pipe) 16b: Flange part 17a: Opening (opening of delivery pipe) 17b: opening C: Clarification tank Cb: The top (top) of the tubular part Cc: Bottom of the tubular part (bottom) D: Inner diameter of tubular part DL: The length of the major axis of the opening (length of the major axis) F: Flow direction of molten glass F1: The flange part of the clarification tank (flange part) F2: Flange part (of the delivery pipe) GR: plate glass (glass items) GS: Liquid level of molten glass GA: Gas storage department GM: molten glass H: height difference O1: The opening of the clarification tank (opening) O2: The opening (of the delivery pipe) S1: Preheating step S2: Assembly steps S3: Melting step S4: Molten glass supply step S5: Forming step S6: Slow cooling step S7: Cut off step

FIG. 1 is a side view of a glass article manufacturing apparatus according to a first embodiment. FIG. 2 is a cross-sectional view of a melting tank, a clarification tank, and a conveying pipe. FIG. 3 is a view showing the upstream side end portion of the clarification tank and the downstream side end portion of the conveying pipe. FIG. 4 is a flow chart of a method for manufacturing glass articles. FIG. 5 is a cross-sectional view of a conveying pipe and a clarification tank showing a preheating step. FIG. 6 is a cross-sectional view of a melting tank, a clarification tank, and a conveying pipe according to a second embodiment. FIG. 7 is a cross-sectional view of a clarification tank and a conveying pipe according to a third embodiment. FIG. 8 is a cross-sectional view illustrating the principle of generation of a gas storage portion.

1: Melting tank (constituent element)

1a: Outlet of the melting tank (outlet)

1aD: Lower end of outflow port

1aU: Upper end (top) of the outflow port

1b: Wall

2: Clarifying tank (constituent element)

2a: Upstream end of the tubular part (upstream end of the clarification tank)

2b: Downstream end of clarification tank (tubular part)

6a, 6b: Glass supply pipeline (constituent components)

7: Tubular part of the clarification tank (tubular part)

7a: Exhaust section

7b: The top of the inner surface of the tubular part (the vertex of the inner surface of the tubular part, the top of the clarification tank)

7c: Bottom of the clarification tank (bottom of the upstream end of the clarification tank)

8a: Flange part of the clarification tank (flange part, first flange part)

8b: flange of clarification tank (flange, second flange)

9a: First opening (opening)

9aD: The lower end of the first opening (the bottom of the first opening)

9aU: Upper end of the first opening

9b: Second opening (opening)

9bU: The upper end of the second opening

10, 14: Transport pipe

10a: Upstream end of the delivery pipe (upstream end)

10b: Downstream end of the conveying pipe (downstream end)

11, 15: Tubular part

11a: The top of the inner surface of the conveying pipe (the top of the inner surface of the downstream end, the top of the conveying pipe)

11b: Bottom of the inner surface of the upstream end (bottom of the delivery pipe)

12a: flange (first flange)

12b: Flange part (second flange part)

13a: Opening (opening of the first flange, opening of the delivery pipe)

13aD: The lower end of the opening of the delivery pipe

13aU: The upper end of the opening of the conveying pipe

13b: Opening part (the opening part of the second flange part, the opening part of the downstream end part of the conveying pipe, the opening part of the second tubular part of the conveying pipe)

13bD: Lower end of the opening of the delivery pipe (bottom of the opening of the second tubular part)

13bU: The upper end of the opening of the downstream end of the conveying pipe (the upper end of the opening of the conveying pipe)

14a: End (upstream end of the delivery pipe)

14b: end

16a: flange (flange of the delivery pipe)

16b: flange

17a: Opening (opening of delivery pipe)

17b: opening

D: Inner diameter of the tubular part

F: Flow direction of molten glass

GS: Liquid level of molten glass

GM: molten glass

H: height difference

Claims (6)

A method for manufacturing glass articles, comprising the steps of heating and melting glass raw materials in a melting tank to generate molten glass, conveying the molten glass flowing out of the outflow port of the melting tank by a conveying pipe, and subjecting the molten glass to a clarification treatment when the molten glass conveyed from the conveying pipe fills the tubular portion of a clarification tank. The method for manufacturing glass articles is characterized in that: the conveying pipe comprises an upstream side end portion connected to the melting tank and a downstream side end portion connected to the tubular portion, the conveying pipe is connected to the tubular portion in a manner that the top of the inner surface of the downstream side end portion is consistent with the top of the inner surface of the tubular portion, and the molten glass flows along the top of the inner surface of the downstream side end portion of the conveying pipe and the top of the inner surface of the tubular portion. The manufacturing method of glass articles according to claim 1, wherein the top of the inner surface of the upstream end of the conveying pipe coincides with the top of the inner surface of the outflow port, and the top of the inner surface of the upstream end The bottom of the inner surface is connected to the melting tank in a manner consistent with the bottom of the inner surface of the outlet. The method of manufacturing a glass article according to claim 1 or 2, wherein the conveying pipe is aligned with the tubular portion in such a manner that the bottom of the inner surface of the downstream end portion coincides with the bottom of the inner surface of the tubular portion. connection. A method for manufacturing a glass article as described in claim 3, wherein the delivery pipe includes an expanded portion whose inner diameter gradually increases toward the downstream side end portion. The manufacturing method of glass articles as described in claim 1 or 2, wherein The conveying pipe is configured in a straight tube shape, and is connected to the tubular portion such that a bottom of an inner surface of the downstream end portion is higher than a bottom of an inner surface of the tubular portion. The method for manufacturing a glass article as described in claim 1 or 2 includes a step of heating the delivery tube and the tubular portion while the delivery tube is separated from the tubular portion.

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