WO2014125954A1 - Method for manufacturing glass plate and device for manufacturing glass plate - Google Patents

Abstract

After making molten glass (12) pass through a tweel (322) that adjusts the flow rate of the molten glass (12), this method for manufacturing a glass plate continuously supplies the molten glass (12) from a lip (324) that forms a flow path therefor onto molten tin (16) inside a tin melting tank (310), forming a plate shape by making the same flow on top of the molten tin (16). A limiting wall (328) that limits the movement of gas is provided above the molten glass (12) in a spout space (S1). Oxidation preventing gas is supplied to a first space (S11) formed by the tweel (322), limiting wall (328), and molten glass (12), and oxidation preventing gas is supplied to a second space (S12) formed by the limiting wall (328), a separating wall (326) and the molten glass (12). The oxidation preventing gas supplied to the first space (S11) and the oxidation preventing gas supplied to the second space (S12) are different.

Description

Glass plate manufacturing method and glass plate manufacturing apparatus

The present invention relates to a glass plate manufacturing method and a glass plate manufacturing apparatus.

The method for producing a glass plate is as follows: a molten glass is passed through a teel that adjusts the flow rate of the molten glass, and then a lip that forms a flow path of the molten glass is placed on the molten tin in the bath. It supplies continuously, makes it flow on this molten tin, and shape | molds in plate shape (for example, refer patent document 1). The space above the molten tin is provided with a partition wall (generally called a front lintel) that divides the spout space in which the lip is disposed and the main space downstream of the spout space. It is done. The main space is sufficiently larger than the spout space and filled with an antioxidant gas (for example, a mixed gas of an inert gas and a reducing gas) that prevents the oxidation of molten tin. The reducing gas (for example, hydrogen gas) reacts with oxygen gas contained in the air mixed in the main space to generate water vapor, thereby preventing oxidation of molten tin.

International Publication No. 2010/013575

The spout space contains tin vapor evaporated from molten tin. A member formed of platinum or a platinum alloy is disposed around the spout space. Platinum or a platinum alloy has low reactivity with molten glass and is used for a member that comes into contact with molten glass.

By the way, when reducing gas is supplied to the spout space, the reducing gas reacts with oxygen gas to generate water vapor, so that the concentration of oxygen gas in the spout space decreases. However, when a reducing gas is supplied to the spout space, a member formed of platinum or a platinum alloy is deteriorated by the reducing gas.

On the other hand, when an inert gas is supplied to the spout space, deterioration of a member formed of platinum or a platinum alloy can be suppressed. However, the concentration of oxygen gas in the spout space is higher than when reducing gas is supplied to the spout space. Therefore, fine particles of tin oxide are formed by the reaction between oxygen gas and tin vapor. The formed fine particles fall on the molten glass and become a glass plate defect.

This invention is made | formed in view of the said subject, Comprising: It aims at provision of the manufacturing method of a glass plate which can suppress deterioration of the member formed with platinum or a platinum alloy, and can reduce the defect of a glass plate. .

In order to solve the above problems, one embodiment of the present invention provides:
After the molten glass is passed through a tool for adjusting the flow rate of the molten glass, the molten glass is continuously supplied from the lip forming the flow path of the molten glass onto the molten tin in the tin bath, and flows on the molten tin. A method of manufacturing a glass plate, which is molded into a plate shape,
A partition wall that divides the upper space of the molten tin into a spout space in which the lip is disposed and a main space downstream of the spout space;
In the spout space, a restriction wall that restricts the movement of gas is provided above the molten glass,
Supplying an antioxidant gas to the first space formed by the twill, the restriction wall, and the molten glass;
Supplying an antioxidant gas to the second space formed by the restriction wall, the partition wall and the molten glass;
The antioxidant gas supplied to the first space is different from the antioxidant gas supplied to the second space.

According to the present invention, there is provided a method for producing a glass plate that can suppress deterioration of a member formed of platinum or a platinum alloy and can reduce defects in the glass plate.

FIG. 1 is a cross-sectional view showing a glass plate manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a partially enlarged view of FIG. FIG. 3 is a sectional view taken along line III-III in FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof is omitted.

FIG. 1 is a cross-sectional view showing a glass plate manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a partially enlarged view of FIG. FIG. 3 is a sectional view taken along line III-III in FIG.

The glass plate manufacturing apparatus 100 manufactures a glass plate by a float process, and includes, for example, a melting device 200, a forming device 300, and a slow cooling device 400 as shown in FIG.

The melting device 200 melts the glass raw material 10 to obtain a molten glass 12. The melting apparatus 200 includes a melting tank 210 that stores the molten glass 12 and a burner 220 that forms a flame above the molten glass 12 that is stored in the melting tank 210. The glass raw material 10 thrown into the melting tank 210 is gradually melted into the molten glass 12 by the radiant heat from the flame formed by the burner 220.

The forming apparatus 300 forms the molten glass 12 supplied from the melting apparatus 200 into a strip-like glass ribbon 14. The forming apparatus 300 includes a tin bath 310 that accommodates the molten tin 16, and the molten glass 12 that is continuously supplied onto the molten tin 16 is caused to flow on the molten tin 16 to be formed into a strip shape. The molten glass 12 is gradually cooled while flowing in a predetermined direction, and becomes gradually hardened. The glass ribbon 14 thus formed is pulled up obliquely from the molten tin 16 in the downstream area of the tin bath 310.

The slow cooling device 400 cools the glass ribbon 14 formed by the forming device 300 while continuously conveying it in a predetermined direction. The slow cooling device 400 includes a furnace body 410 that forms a slow cooling chamber 402 for slowly cooling the glass ribbon 14. The temperature of the slow cooling chamber 402 decreases as it goes from the inlet to the outlet of the slow cooling chamber 402. The temperature of the slow cooling chamber 402 is adjusted by a heater or the like (not shown). The glass ribbon 14 drawn out from the slow cooling device 400 is cut into a predetermined size by a cutting machine, and a glass plate as a product is obtained.

Next, the molding apparatus 300 will be mainly described with reference to FIGS. As shown in FIG. 2, the molding apparatus 300 includes a twill 322, a lip 324, a partition wall 326, a limiting wall 328, a first gas supply unit 330, and a second gas supply unit 332.

The twill 322 adjusts the flow rate of the molten glass 12. The twill 322 can move up and down with respect to the lip 324 forming the flow path of the molten glass 12 and is inserted into the flow path of the molten glass 12 to adjust the opening degree of the flow path of the molten glass 12. The cross-sectional shape of the lower surface of the twill 322 may be a curved shape convex downward.

The twill 322 preferably has a protective layer 322b formed of platinum or a platinum alloy on the surface in contact with the molten glass 12. The protective layer 322b is formed on at least a part of the main body 322a of the twill 322, and suppresses the reaction between the brick constituting the main body 322a and the molten glass 12.

It is preferable that a flow path pipe 334 for connecting the molding apparatus 300 and the melting apparatus 200 is provided on the upstream side of the twill 322. The channel tube 334 forms a channel for the molten glass 12. The channel tube 334 may be formed of platinum or a platinum alloy that does not easily react with the molten glass 12. In order to ensure the fluidity of the molten glass 12 in the flow channel tube 334, it is possible to pass an electric current through the flow channel tube 334 and heat the molten glass 12 in the flow channel tube 334 with Joule heat of the flow channel tube 334. It is.

The lip 324 continuously supplies the molten glass 12 whose flow rate is adjusted by the twill 322 onto the molten tin 16 in the tin bath 310. The lip 324 is made of a refractory material such as brick, and is installed in the tin bath 310. On both the left and right sides of the molten glass 12 flowing on the lip 324, lateral walls (not shown) may be provided so that the molten glass 12 does not spill left and right.

The partition wall 326 partitions the upper space S0 of the molten tin 16 into a spout space S1 in which the lip 324 is disposed and a main space S2 on the downstream side of the spout space S1. The partition wall 326 is provided above the molten glass 12, and the molten glass 12 supplied onto the molten tin 16 in the spout space S1 passes under the partition wall 326 and moves to the main space S2.

The main space S2 is a space for forming the molten glass 12 into a strip-like glass ribbon 14, and is sufficiently larger than the spout space S1. A main gas supply path 342 is provided in the roof 340 forming the ceiling surface of the main space S2, and a heater 344 as a heating source is inserted into the main gas supply path 342.

The main gas supply path 342 supplies an antioxidant gas to the main space S2 in order to prevent the molten tin 16 from being oxidized. The antioxidant gas may be, for example, a mixed gas of an inert gas and a reducing gas. For example, the main gas supply path 342 supplies a mixed gas containing 0% to 15% by volume of hydrogen gas as an antioxidant gas, and the balance of nitrogen gas and unavoidable impurity gas to the main space S2. The hydrogen gas reacts with the oxygen gas contained in the air mixed in the main space S2 to generate water vapor, thereby reducing the oxygen gas. The main space S2 has a pressure higher than the atmospheric pressure in order to limit the mixing of outside air.

In order to adjust the temperature distribution of the glass ribbon 14, a plurality of heaters 344 are provided, for example, at intervals in the flow direction and the width direction of the glass ribbon 14. The output of the heater 344 is controlled so that the temperature of the glass ribbon 14 decreases from the upstream side toward the downstream side. Further, the output of the heater 344 is controlled so that the thickness of the glass ribbon 14 is uniform in the width direction.

The restriction wall 328 restricts the movement of the gas above the molten glass 12 in the spout space S1. The limiting wall 328 is provided between the twill 322 and the partition wall 326 and is provided above the molten glass 12. Unlike the twill 322, the limiting wall 328 does not contact the molten glass 12, and thus does not need to have a protective layer formed of platinum or a platinum alloy.

The restriction wall 328 is inserted into the spout space S1 from the opening of the block 346 that forms the ceiling surface of the spout space S1, and forms a gap with the molten glass 12. The limiting wall 328 may be configured similarly to the main body 322a of the twill 322 in order to reduce manufacturing costs and management costs.

As shown in FIG. 3, support grooves 348a and 350a for supporting the limiting wall 328 may be provided in the left side wall 348 of the spout space S1 and the right side wall 350 of the spout space S1, respectively. The support grooves 348 a and 350 a restrict the movement of the limiting wall 328 in the flow direction of the molten glass 12. Therefore, for example, when the limiting wall 328 is split in half at the center in the left-right direction (the center in the vertical direction in FIG. 3), the broken pieces can support each other and can be prevented from falling onto the molten glass 12.

The support grooves 348a and 350a may guide the restriction wall 328 in the vertical direction when the restriction wall 328 is inserted into the spout space S1 from the opening of the block 346. The support grooves 348 a and 350 a extend downward from the upper end of the restriction wall 328, and the lower surfaces of the support grooves 348 a and 350 a lock the restriction wall 328.

The first gas supply unit 330 supplies the antioxidant gas to the first space S11 formed by the twill 322, the restriction wall 328, and the molten glass 12. For example, the first gas supply unit 330 may supply nitrogen gas, which is an inert gas, as the antioxidant gas to the first space S11. The first space S11 may be at a pressure higher than the atmospheric pressure in order to limit the mixing of outside air. The inert gas may not be nitrogen gas but may be argon gas or the like.

The first gas supply unit 330 includes an opening formed in the left side wall 348 and the right side wall 350 of the spout space S1. The opening is connected to an antioxidant gas supply source through a pipe provided with a flow rate adjusting valve, an opening / closing valve, and the like. In addition, the 1st gas supply part 330 may be comprised by the pipe | tube etc. which are penetrated by the opening part of the left side wall 348 and the right side wall 350 of spout space S1.

The second gas supply unit 332 supplies the antioxidant gas to the second space S12 formed by the restriction wall 328, the partition wall 326, and the molten glass 12. The antioxidant gas may be, for example, a mixed gas of an inert gas and a reducing gas. For example, the second gas supply unit 332 supplies a mixed gas containing 0 volume% to 15 volume% of hydrogen gas as an antioxidant gas, and the balance of nitrogen gas and unavoidable impurity gas to the second space S12. The hydrogen gas reacts with the oxygen gas contained in the air mixed in the second space S12 to generate water vapor, thereby reducing the oxygen gas. The second space S12 may be at a pressure higher than the atmospheric pressure in order to limit the mixing of outside air.

The second gas supply unit 332 includes openings formed in the left side wall 348 and the right side wall 350 of the spout space S1. The opening is connected to an antioxidant gas supply source through a pipe provided with a flow rate adjusting valve, an opening / closing valve, and the like. Note that the second gas supply unit 332 may be configured by a pipe or the like that is inserted through the openings of the left side wall 348 and the right side wall 350 of the spout space S1.

The spout space S1 is composed of the first space S11 and the second space S12. The movement of the gas between the first space S11 and the second space S12 is restricted by the restriction wall 328, the upstream first space S11 is filled with nitrogen gas, and the downstream second space S12 is filled with nitrogen gas and hydrogen. Filled with gas mixture.

Since the first space S11 on the upstream side is filled with nitrogen gas, there is little hydrogen gas around the tween 322 that forms the first space S11 and the channel pipe 334 provided on the upstream side of the twill 322, and platinum or platinum Deterioration of a member formed of an alloy can be suppressed.

Further, since the downstream second space S12 is filled with a mixed gas of nitrogen gas and hydrogen gas, the concentration of oxygen gas in the second space S12 is lower than that when only the nitrogen gas is filled. Therefore, in the second space S <b> 12, the reaction between the oxygen gas and the tin vapor is difficult to proceed, tin oxide fine particles are not easily generated, and the fine particles are unlikely to fall on the molten glass 12. Therefore, the defect of a glass plate can be reduced.

In addition, although the 1st gas supply part 330 of this embodiment supplied nitrogen gas to 1st space S11, you may supply mixed gas of nitrogen gas and hydrogen gas to 1st space S11. The concentration (volume%) of hydrogen gas in the antioxidant gas supplied from the first gas supply unit 330 to the first space S11 is equal to the hydrogen gas in the antioxidant gas supplied from the second gas supply unit 332 to the second space S12. The concentration should be lower than the concentration (volume%). It is possible to achieve both suppression of deterioration of a member formed of platinum or a platinum alloy and reduction of defects in the glass plate.

The hydrogen gas concentration (volume%) in the antioxidant gas supplied to the second space S12 by the second gas supply unit 332 is the hydrogen gas concentration (volume) in the antioxidant gas supplied from the main gas supply path 342 to the main space S2. %). Since the hydrogen gas concentration gradually decreases in the order of the main space S2, the second space S12, and the first space S11, it is possible to suppress deterioration of members formed of platinum or a platinum alloy and reduce defects in the glass plate. It is possible to achieve both efficiently.

As mentioned above, although the manufacturing method of a glass plate and embodiment of the manufacturing apparatus of a glass plate were demonstrated, this invention is not limited to the said embodiment etc., A various deformation | transformation and improvement are possible.

For example, in the above embodiment, hydrogen gas is used as a reducing gas capable of reducing oxygen gas, but acetylene gas or the like may be used, for example. The type of reducing gas may not be the same in the first gas supply unit 330, the second gas supply unit 332, and the main gas supply path 342. The reducing power of the reducing gas is different for each type of reducing gas. For example, acetylene gas has a higher reducing power than hydrogen gas. Therefore, the concentration (volume%) of the reducing gas in the antioxidant gas supplied from the first gas supply unit 330 to the first space S11 is the same as that in the antioxidant gas supplied from the second gas supply unit 332 to the second space S12. In some cases, the concentration may be equal to or higher than the concentration (% by volume) of the reducing gas. As such a case, the reducing gas from the second gas supply unit 332 has a higher reducing power than the reducing gas from the first gas supply unit 330. Accordingly, if the antioxidant gas supplied from the first gas supply unit 330 to the first space S11 and the antioxidant gas supplied from the second gas supply unit 332 to the second space S12 are different, platinum or a platinum alloy is used. It is possible to achieve both suppression of deterioration of the formed member and reduction of defects in the glass plate.

In addition, although one restriction wall 328 of the above embodiment is provided, a plurality of restriction walls 328 may be provided at intervals along the flow of the molten glass 12.

This application is based on Japanese Patent Application No. 2013-028628 filed on Feb. 18, 2013, the contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 10 Glass raw material 12 Molten glass 14 Glass ribbon 16 Molten tin 100 Glass plate manufacturing apparatus 200 Melting apparatus 300 Molding apparatus 310 Tin bathtub 322 Tail 324 Lip 326 Partition wall 328 Restriction wall 330 First gas supply part 332 Second gas supply part 342 Main gas supply path 400 Slow cooling device S0 Upper space S1 of molten tin Spout space S11 First space S12 Second space S2 Main space

Claims (14)

After the molten glass is passed through a tool for adjusting the flow rate of the molten glass, the molten glass is continuously supplied from the lip forming the flow path of the molten glass onto the molten tin in the tin bath, and flows on the molten tin. A method of manufacturing a glass plate, which is molded into a plate shape,
A partition wall that divides the upper space of the molten tin into a spout space in which the lip is disposed and a main space downstream of the spout space;
In the spout space, a restriction wall that restricts the movement of gas is provided above the molten glass,
Supplying an antioxidant gas to the first space formed by the twill, the restriction wall, and the molten glass;
Supplying an antioxidant gas to the second space formed by the restriction wall, the partition wall and the molten glass;
The method for producing a glass plate, wherein the antioxidant gas supplied to the first space is different from the antioxidant gas supplied to the second space. The glass plate production according to claim 1, wherein the concentration of the reducing gas in the antioxidant gas supplied to the first space is lower than the concentration of the reducing gas in the antioxidant gas supplied to the second space. Method. The inert gas as an antioxidant gas is supplied to the first space, and a mixed gas of an inert gas and a reducing gas is supplied as the antioxidant gas to the second space. Manufacturing method of glass plate. The concentration of the reducing gas in the antioxidant gas supplied to the second space is lower than the concentration of the reducing gas in the antioxidant gas supplied to the main space according to any one of claims 1 to 3. The manufacturing method of the glass plate of description. The method for producing a glass plate according to any one of claims 1 to 4, wherein the twill has a protective layer formed of platinum or a platinum alloy on a surface in contact with the molten glass. On the upstream side of the twill, a flow path tube that forms the flow path of the molten glass is provided,
The method for producing a glass plate according to any one of claims 1 to 5, wherein the flow channel tube is formed of platinum or a platinum alloy. The method for producing a glass plate according to any one of claims 1 to 6, wherein a support groove for supporting the restriction wall is formed on a side wall of the spout space. A twill to adjust the flow rate of the molten glass,
A lip for continuously supplying molten glass whose flow rate is adjusted with the twill onto the molten tin in the tin bath;
A partition wall that divides the upper space of the molten tin into a spout space in which the lip is disposed and a main space on the downstream side of the spout space;
In the spout space, a restriction wall that restricts the movement of gas above the molten glass;
A first gas supply unit that supplies an antioxidant gas to a first space formed by the twill, the restriction wall, and the molten glass;
A second gas supply unit that supplies an antioxidant gas to a second space formed by the restriction wall, the partition wall, and the molten glass;
An apparatus for manufacturing a glass plate, wherein an antioxidant gas supplied to the first space by the first gas supply unit is different from an antioxidant gas supplied to the second space by the second gas supply unit. The concentration of the reducing gas in the antioxidant gas supplied to the first space by the first gas supply unit is the concentration of the reducing gas in the antioxidant gas supplied to the second space by the second gas supply unit. The manufacturing apparatus of the glass plate of Claim 8 lower than this. The first gas supply unit supplies an inert gas as an antioxidant gas to the first space,
The said 2nd gas supply part is a manufacturing apparatus of the glass plate of Claim 8 or 9 which supplies the mixed gas of an inert gas and a reducing gas as antioxidant gas to the said 2nd space. The concentration of the reducing gas in the antioxidant gas supplied to the second space by the second gas supply unit is lower than the concentration of the reducing gas in the antioxidant gas supplied to the main space. The glass plate manufacturing apparatus according to any one of 10. The apparatus for producing a glass plate according to any one of claims 8 to 11, wherein the twill has a protective layer formed of platinum or a platinum alloy on a surface in contact with the molten glass. Further comprising a flow channel tube for forming a flow channel for the molten glass on the upstream side of the twill,
The glass plate manufacturing apparatus according to any one of claims 8 to 12, wherein the channel tube is formed of platinum or a platinum alloy. The glass plate manufacturing apparatus according to any one of claims 8 to 13, wherein a support groove for supporting the restriction wall is formed on a side wall of the spout space.

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