WO2020246275A1

WO2020246275A1 - Glass plate manufacturing device and glass plate manufacturing method

Info

Publication number: WO2020246275A1
Application number: PCT/JP2020/020377
Authority: WO
Inventors: 仁金谷; 光晴野田
Original assignee: 日本電気硝子株式会社
Priority date: 2019-06-07
Filing date: 2020-05-22
Publication date: 2020-12-10
Also published as: KR20220016823A; JP2020200205A; JP7144750B2; CN113677636A

Abstract

The main configuration of this glass plate manufacturing device 1 is housing, in a molding furnace 4, a mold 2 used for molding molten glass 5 into a glass ribbon 6 with the down-draw process and a support body 3 for supporting both ends in the width direction of the mold 2; this glass plate manufacturing device 1 is configured by arranging a heater 10 on the support body 3.

Description

Glass plate manufacturing equipment and glass plate manufacturing method

The present invention relates to an apparatus and method for manufacturing a glass plate by a down draw method.

As is well known, as a typical example of the downdraw method adopted in the field of glass plate manufacturing, a glass ribbon is continuously molded while molten glass is allowed to flow down along both surfaces of a molded body having a substantially wedge-shaped cross section. There is an overflow down draw method. As other down draw methods, a slot down draw method and the like are known.

Patent Document 1 discloses an apparatus for manufacturing a glass plate by an overflow down draw method. The molded body, which is a component of this device, is supported at both ends in the width direction (longitudinal direction) by a support.

WO2012 / 132309

Generally, the periphery of the molded product is maintained at a high temperature by heating or the like. However, as disclosed in Patent Document 1, when both ends in the width direction of the molded body are supported by the support, the heat around both ends in the width direction is taken away by the support.

Therefore, in the molded body, the temperature of the portion in contact with both ends in the width direction of the glass ribbon is lower than that in contact with the central portion in the width direction of the glass ribbon to be molded. As a result, there is a risk of increasing the uneven thickness (unbalanced thickness) of the glass plate to be a product and causing devitrification, and it becomes difficult to obtain a product of stable quality.

From the above viewpoint, it is an object of the present invention to maintain the ambient temperature at both ends of the molded product in the width direction at an appropriate temperature and reduce the problems of uneven thickness and devitrification of the glass plate.

The first aspect of the present invention, which was devised to solve the above problems, supports a molded body used for molding molten glass into a glass ribbon by a down draw method and both ends in the width direction of the molded body. It is a glass plate manufacturing apparatus in which a support is housed in a molding furnace, and is characterized in that a heater is installed on the support.

According to such a configuration, since the support supporting both ends in the width direction of the molded body is heated by the heater, the temperature drop around both ends in the width direction in the molding furnace is suppressed. Therefore, in the molded body, the temperature difference between the portion in contact with the central portion in the width direction of the glass ribbon to be molded and the portion in contact with both ends in the width direction of the glass ribbon is reduced. As a result, the uneven thickness (unbalanced thickness) of the glass plate to be a product is reduced and devitrification is less likely to occur, so that it is possible to provide a product of stable quality.

In this configuration, the support is preferably refractory brick.

By doing so, the strength at high temperature can be ensured, and the deformation of the support can be prevented.

In the above configuration, the heater may be arranged in the hole formed in the support.

In this way, only the heater can be replaced, and maintenance, inspection, management, etc. can be easily performed.

In the above configuration, the heater may be arranged so as to straddle the hole formed in the support and the hole formed in the furnace wall of the molding furnace.

In this way, the heater can be properly supported, and the heater can be easily installed or replaced.

In this configuration, the heater has a rod shape, the holes formed in the support are through holes, and the holes formed in the furnace wall of the molding furnace are through holes. The heater may be inserted.

In this way, it is possible to install a heater from outside the molding furnace and replace the heater during operation. Further, it is possible to wire the heater in a state where the heater extends to the outside of the molding furnace. Moreover, by making the heater rod-shaped, the heater can be elongated. As a result, the through holes formed in the support and the furnace wall can be made smaller in diameter, and the amount of heat escaping from the molding furnace can be reduced.

In this configuration, the support may be provided with an opening window for exposing the heater to the internal space of the molding furnace.

In this way, the heat from the heater is efficiently transferred to the internal space of the molding furnace through the opening window, so that the atmosphere around both ends in the width direction of the molded body can be raised. Therefore, the temperature difference between the portion of the molded product that contacts the central portion of the glass ribbon in the width direction and the portion that contacts both ends of the glass ribbon in the width direction is further reduced.

In this configuration, the opening window is provided in the middle portion of the hole formed in the support in the central axis direction, and is formed in the support at both ends of the hole formed in the support in the central axis direction. A sealing material may be filled between the formed hole and the heater.

When an opening window is provided, the atmosphere inside the molding furnace tends to flow out from between the hole of the support and the heater through the opening window, and the temperature inside the molding furnace tends to decrease accordingly. On the other hand, if a sealing material is filled between the hole of the support and the heater at both ends in the direction of the central axis of the hole of the support, the outflow of the atmosphere in the molding furnace can be prevented and the inside of the molding furnace can be prevented. The temperature can be maintained favorably.

In the configuration in which the opening window is provided, a sealing material may be filled between the hole formed in the furnace wall of the molding furnace and the heater.

Even in this case, the outflow of the atmosphere in the molding furnace can be prevented, and the temperature in the molding furnace can be maintained suitably.

The second aspect of the present invention, which was devised to solve the above problems, is a down-draw method in which a molded product and a support supporting both ends of the molded product in the width direction are housed in a molding furnace. A glass plate manufacturing method including a molding step of molding molten glass into a glass ribbon using the molded body, wherein the support is heated by a heater installed on the support in the molding step. Be characterized.

Even with this method, the problems of uneven thickness (unevenness) and devitrification of the glass plate to be the product are less likely to occur, and it is possible to provide a product of stable quality, as in the case of the above-mentioned matters. Become.

According to the present invention, the ambient temperature at both ends in the width direction of the molded product can be maintained at an appropriate temperature, and the problems of uneven thickness and devitrification of the glass plate can be reduced.

It is a vertical sectional side view which shows the main part of the glass plate manufacturing apparatus which concerns on embodiment of this invention. It is a vertical sectional front view cut according to line AA of FIG. It is a vertical sectional side view cut according to the line BB of FIG. It is a vertical sectional front view cut according to line CC of FIG. It is a vertical sectional side view which enlarged one side part of the main part of FIG. It is a vertical sectional front view which enlarged one side part of the main part of FIG. It is a vertical sectional side view which enlarged one side part of the main part of FIG. It is a vertical sectional front view which enlarged one side part of the main part of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[Glass plate manufacturing equipment]
FIG. 1 is a vertical sectional side view showing a main part of the glass plate manufacturing apparatus according to the embodiment of the present invention, and FIG. 2 is a vertical sectional front view cut according to lines AA of FIG. Further, FIG. 3 is a vertical sectional side view cut according to the line BB of FIG. 2, and FIG. 4 is a vertical sectional front view cut according to the line CC of FIG. As shown in each of these figures, the glass plate manufacturing apparatus 1 includes a molded body 2, a pair of supports 3, and a molding furnace 4 that houses the molded body 2 and the supports 3 as main components. In the molded body 2, the molten glass 5 is molded into the glass ribbon 6 by the overflow down draw method at the intermediate portion in the width direction. The pair of supports 3 are arranged to support both ends in the width direction of the molded body 2. Here, the "width direction" is the left-right direction in FIGS. 2 and 4, and in the present embodiment, means the longitudinal direction of the molded body 2.

The molded body 2 has an overflow groove 7 formed at the top and a pair of surfaces 8 on which the molten glass 5 overflowing from the overflow groove 7 flows down. Each of the pair of surfaces 8 is composed of an upper vertical surface portion 8a and a lower inclined surface portion 8b (see FIGS. 1 and 4). The pair of vertical surface portions 8a are formed on the rectangular parallelepiped portion 2a above the molded body 2. The pair of inclined surface portions 8b are formed on the tapered portion 2b at the lower part of the molded body 2 that gradually becomes thinner (see FIG. 1). The molten glass that has flowed down the pair of vertical surface portions 8a and the pair of inclined surface portions 8b is fused and integrated at the lower end portion 2c of the molded body 2, and then sent downward via a cooling roller or the like (not shown) to be glass. It is continuously molded as a ribbon 6. The molded body 2 is made of refractory bricks such as dense zircon, alumina-based, and zirconia-based.

Support 3 is a rectangular parallelepiped refractory brick. Both ends in the width direction of the molded body 2 have a rectangular parallelepiped protruding portion 2d and an end surface portion 2e on the outer side in the width direction of the tapered portion 2b (see FIGS. 2 and 4). The projecting portion 2d projects from the upper portion of the molded body 2 to the outside in the width direction. Further, the protruding portion 2d is placed on the upper surface of the support 3, respectively. As a result, the weight of the molded body 2 is received by the pair of supports 3. In the present embodiment, the lower end of the protruding portion 2d of the molded body 2 is lower than the upper end of the tapered portion 2b (inclined surface portion 8b). In other words, the upper end of the support 3 is lower than the upper end of the inclined surface portion 8b of the molded body 2. The end face portion 3a on the inner side in the width direction of the support 3 is in contact with the end face portion 2e on the outer side in the width direction of the tapered portion 2b of the molded body 2 (see FIGS. 2 and 4). The support 3 is made of refractory bricks such as dense zircon, alumina zircon, and mullite.

The furnace wall of the molding furnace 4 includes an end wall portion 4a that covers the outer side of the protruding portion 2d of the molded body 2 in the width direction, and a side wall portion 4b that covers the outer sides of both surfaces 8 of the molded body 2 in the front-rear direction. , The ceiling wall portion 4c covering the upper side of the molded body 2 and the bottom wall portion 4d covering the lower side of the molded body 2. Here, the "front-back direction" is the left-right direction in FIGS. 1 and 3, and means the thickness direction of the molded body 2. In the central portion of the bottom wall portion 4d, a slit-shaped opening 4e elongated in the width direction for passing the molten glass 5 fused and integrated at the lower end portion 2c of the molded body 2 is formed (FIG. 1). And see FIG. 2).

The base 9 is placed on each of the four corners of the bottom wall 4d of the molding furnace 4. Each of the pair of supports 3 is placed on the pair of bases 9. The furnace walls 4a to 4d of the molding furnace 4 are composed of a plurality of refractory bricks. The base 9 is also made of refractory bricks.

The end face portion 3b on the outer side in the width direction of the support 3 is separated from the end wall portion 4a of the molding furnace 4 (see FIGS. 2 and 4). On the other hand, the outer side surface portion 3c of the support 3 in the front-rear direction is in contact with or close to the side wall portion 4b of the molding furnace 4 (see FIGS. 1 and 3).

A plurality of heaters 10 are installed on each of the pair of supports 3. In the illustrated example, the heaters 10 are installed at two locations, the upper stage and the lower stage of each support 3, respectively (see FIGS. 2 and 4). Each heater 10 has a rod shape with a circular cross section, and these heaters 10 are inserted into through holes 11 formed in each support 3. These through holes 11 are formed separately at two locations above and below each support 3 so as to extend along the front-rear direction. Specifically, the through holes 11 formed at two upper and lower positions in the central portion in the front-rear direction of each support 3 and the through holes 11 formed at two upper and lower positions at both ends in the front-rear direction apart from these are formed. They are arranged on the same axis (see FIG. 3). Further, the side wall portions 4b of the molding furnace 4 are also formed with through holes 12 communicating with the through holes 11 (through holes 11 at both ends in the front-rear direction) of the support 3. Each heater 10 is inserted across the through hole 11 of the support 3 and the through hole 12 of the side wall portion 4b, and extends outward from the side wall portion 4b.

Although not shown, a heater for heating the molten glass 5 flowing down both surfaces 8 of the molded body 2 is mainly arranged on the side wall portion 4b of the molding furnace 4 so as not to interfere with the support 3. There is.

FIG. 5 is an enlarged vertical side view of one side of the main part of FIG. 1, and FIG. 6 is an enlarged vertical front view of one side of the main part of FIG. 2. Further, FIG. 7 is an enlarged vertical sectional side view of one side portion of the main portion of FIG. 3, and FIG. 8 is an enlarged vertical sectional front view of one side portion of the main portion of FIG. As shown in each of these figures, the support 3 is formed with an opening window 13 for exposing the two heaters 10 to the internal space 4x of the molding furnace 4.

These opening windows 13 are formed in the middle portion of the through hole 11 in the central axis direction (two locations on both sides of the center in the central axis direction). Specifically, concave opening windows 13 are formed between the through holes 11 in the central portion in the front-rear direction and the through holes 11 at both ends in the front-rear direction, and each through hole 11 is formed in these opening windows 13. Is understood. Further, these opening windows 13 have a shape in which the length in the front-rear direction gradually becomes longer as they move from the upper side to the lower side, and are formed so as not to overlap with the molded body 2 (tapered portion 2b). (See FIG. 5). Then, in these opening windows 13, the inner edge portion in the front-rear direction is inclined so as to follow the inclined surface portion 8b of the molded body 2, and the outer edge portion in the front-rear direction is formed so as to be along the vertical direction. There is.

A sealing material 14 is filled between the through holes 11 formed at both ends of the support 3 in the front-rear direction and the heater 10. In other words, the sealing material 14 is filled over the entire circumference of the heater 10 at both ends in the central axis direction of the through holes 11 formed at two positions of the support 3. A sealing material 15 is also filled between the through hole 12 formed in the side wall portion 4b of the molding furnace 4 and the heater 10 over the entire circumference of the heater 10. These sealing

materials

14 and 15 are heat insulating materials and are made of, for example, refractory fibers.

Although the above description based on FIGS. 5 to 8 is for only one side of the main part of the glass plate manufacturing apparatus 1, the same description is applied to the other side of the main part.

According to the glass plate manufacturing apparatus 1 having the above configuration, the following effects are exhibited.

Since the support 3 that supports both ends in the width direction of the molded body 2 is heated by the heater 10, both ends in the width direction in the internal space 4x of the molding furnace 4 (particularly, the end faces 2e on the outer side in the width direction of the tapered portion 2b). The temperature drop around the is suppressed. Therefore, the temperature difference between the portion of the molded body 2 in contact with the central portion in the width direction of the glass ribbon 6 and the portion in contact with both ends in the width direction of the glass ribbon 6 is reduced. As a result, the uneven thickness (unbalanced thickness) of the glass plate to be a product is reduced and devitrification is less likely to occur, so that it is possible to provide a product of stable quality. As described above, a heater (not shown) is provided on the side wall portion 4b of the molding furnace 4, but this heater is not capable of sufficiently suppressing a temperature drop due to heat being taken away by the support 3. Absent.

Further, since the heater 10 is inserted through the through hole 11 formed in the support 3, only the heater 10 can be replaced, and maintenance, inspection, management, and the like can be easily performed. Moreover, since the heater 10 is also inserted through the through hole 12 formed in the side wall portion 4b of the molding furnace 4, the heater 10 can be replaced from the outside of the molding furnace 4, and maintenance, inspection, management, etc. can be performed. It can be done more easily.

Further, since the support 3 is formed with an opening window 13 for exposing the heater 10 to the internal space 4x of the molding furnace 4, the heat from the heater 10 is efficiently molded through these opening windows 13. It is transmitted to the internal space 4x of the furnace 4. As a result, the temperature drop around both end portions in the width direction of the molded body 2 (particularly, the end face portions 2e on the outer side in the width direction of the tapered portion 2b) is further suppressed. Moreover, as shown in FIG. 5, the opening window 13 does not overlap with the molded body 2 and has a shape in which the length in the front-rear direction gradually becomes longer as it moves from the upper side to the lower side. , The heat from the heater 10 can be transferred to the internal space 4x of the molding furnace 4 as much as possible.

Further, when the opening window 13 is provided, the atmosphere inside the molding furnace 4 tends to flow out from between the through

holes

11 and 12 and the heater 10 through the opening window 13, and the temperature inside the molding furnace 4 rises accordingly. It is easy to drop. On the other hand, in the glass plate manufacturing apparatus 1 according to the present embodiment, the sealing material 14 is provided between the through hole 11 and the heater 10 at both ends of the through hole 11 formed in the support 3 in the central axis direction. Is filled. In addition to this, the sealing material 15 is also filled between the through hole 12 formed in the side wall portion 4b of the molding furnace 4 and the heater 10. As a result, the outflow of the atmosphere in the molding furnace 4 can be prevented, and the temperature in the molding furnace 4 can be suitably maintained.

The glass plate manufacturing apparatus 1 according to the present invention is not limited to the above embodiment, and various variations as shown below are possible.

That is, in the above embodiment, the through hole 11 is formed in the support 3, but a hole that does not penetrate the support 3 may be formed. Further, although the heater 10 has a rod shape, it may be a heater having a shape other than the rod shape. Further, the heater 10 may be embedded in the support 3. Further, the number of heaters 10 per support 3 is not limited to two, and may be one or three or more, or the heaters 10 are arranged in a plurality of upper and lower stages and in a plurality of rows. It may be. Further, in the above embodiment, one opening window 13 is configured to expose all the heaters 10 in a plurality of upper and lower stages, but a plurality of opening windows 13 are formed in the upper and lower portions, and the opening windows 13 are formed in a plurality of upper and lower stages. The heaters 10 in the stage may be configured to be exposed one by one. Further, although the through hole 12 is formed in the side wall portion 4b of the molding furnace 4, a hole that does not penetrate the side wall portion 4b may be formed, or the hole may not be formed. Moreover, although the support 3 is separated from the end wall portion 4a of the molding furnace 4, the support 3 may be brought into contact with or close to the end wall portion 4a. In that case, holes extending in the width direction may be formed in the support 3, holes may also be formed in the end wall portion 4a, and the heater 10 may be inserted across these holes.

Further, in the above embodiment, the upper end of the support 3 is made lower than the upper end of the inclined surface portion 8b of the molded body 2, but the upper end of the support 3 is made equal to or higher than the upper end of the inclined surface portion 8b. You may.

Further, in the above embodiment, the present invention is applied to the case where the molten glass 5 is formed into the glass ribbon 6 by the overflow down draw method, but the molded body used for forming the molten glass into the glass ribbon by the slot down draw method and The present invention can be similarly applied to a support that supports both ends in the width direction.

[Glass plate manufacturing method]
Next, a glass plate manufacturing method according to another embodiment of the present invention will be described. With reference to FIGS. 1 to 8, in this glass plate manufacturing method, a molded body 2 and a support 3 that supports both ends in the width direction of the molded body 2 are housed in a molding furnace 4, and a down draw is performed. A molding step of molding the molten glass 5 into a glass ribbon 6 by using a molded body 2 by a method is provided. Then, in this molding step, the support 3 is heated by the heater 10 installed on the support 3. Therefore, even in the case of this glass plate manufacturing method, problems of uneven thickness (unevenness) and devitrification of the glass plate to be a product are unlikely to occur for the same reason as described above for the glass plate manufacturing apparatus 1. Therefore, it becomes possible to provide products of stable quality.

1 Glass plate manufacturing equipment 2 Molded body 3 Support 4 Molding furnace 4a Furnace wall (end wall part)
4b Furnace wall (side wall)
4x Internal space of the molding furnace 5 Molten glass 6 Glass ribbon 10 Heater 11 Through hole formed in the support 12 Through hole formed in the furnace wall 13 Opening window 14 Sealing material for the support 15 Sealing material for the furnace wall

Claims

A glass plate manufacturing apparatus in which a molded body used for molding molten glass into a glass ribbon by a down-draw method and a support supporting both ends of the molded body in the width direction are housed in a molding furnace.
A glass plate manufacturing apparatus characterized in that a heater is installed on the support.
The glass plate manufacturing apparatus according to claim 1, wherein the support is refractory bricks.
The glass plate manufacturing apparatus according to claim 1 or 2, wherein the heater is arranged in a hole formed in the support.
The glass plate manufacturing apparatus according to claim 3, wherein the heater is arranged so as to straddle the holes formed in the support and the holes formed in the furnace wall of the molding furnace.
The heater has a rod shape, the holes formed in the support are through holes, and the holes formed in the furnace wall of the molding furnace are through holes, and the heater is inserted through these through holes. The glass plate manufacturing apparatus according to claim 4.
The glass plate manufacturing apparatus according to claim 4 or 5, wherein an opening window for exposing the heater to the internal space of the molding furnace is formed on the support.
The opening window is provided in the middle portion in the central axis direction of the hole formed in the support.
The glass plate manufacturing according to claim 6, wherein a sealing material is filled between the holes formed in the support and the heater at both ends of the holes formed in the support in the direction of the central axis. apparatus.
The glass plate manufacturing apparatus according to claim 6 or 7, wherein a sealing material is filled between the hole formed in the furnace wall of the molding furnace and the heater.
A molded body and a support supporting the protrusions formed at both ends of the molded body in the width direction are housed in the molding furnace, and the molten glass is made into a glass ribbon by the down draw method using the molded body. It is a glass plate manufacturing method including a molding process for molding.
A method for manufacturing a glass plate, which comprises heating the support with a heater installed on the support in the molding step.