阅读说明：本技术 玻璃板制造装置以及玻璃板制造方法 (Glass plate manufacturing device and glass plate manufacturing method ) 是由 金谷仁 野田光晴 于 2020-05-22 设计创作，主要内容包括：将在成形炉(4)内收容有为了利用下拉法将熔融玻璃(5)成形为玻璃带(6)而使用的成形体(2)、以及对成形体(2)的宽度方向两端部进行支承的支承体(3)的结构作为主要结构的玻璃板制造装置(1)构成为,在支承体(3)设置有加热器(10)。(A glass plate manufacturing apparatus (1) mainly configured by a structure in which a forming body (2) used for forming molten glass (5) into a glass ribbon (6) by a downdraw method and a support body (3) supporting both widthwise ends of the forming body (2) are housed in a forming furnace (4) is configured such that a heater (10) is provided on the support body (3).)

1. A glass plate manufacturing apparatus, which houses a forming body used for forming molten glass into a glass ribbon by a down-draw method and a support body for supporting both widthwise end portions of the forming body,

the glass sheet manufacturing apparatus is characterized in that,

a heater is provided on the support body.

2. The glass sheet manufacturing apparatus according to claim 1,

the support body is a refractory brick.

3. Glass sheet manufacturing apparatus according to claim 1 or 2,

the heater is disposed in a hole formed in the support body.

4. The glass sheet manufacturing apparatus according to claim 3,

the heater is disposed across a hole formed in the support and a hole formed in a wall of the forming furnace.

5. The glass sheet manufacturing apparatus according to claim 4,

the heater has a rod shape, the hole formed in the support is a through hole, the hole formed in the furnace wall of the forming furnace is a through hole, and the heater penetrates through the through holes.

6. Glass sheet manufacturing apparatus according to claim 4 or 5,

the support body is provided with an opening window for exposing the heater in the inner space of the forming furnace.

7. The glass sheet manufacturing apparatus according to claim 6,

the opening window is provided at an intermediate portion in a central axis direction of the hole formed in the support body,

a seal is filled between the hole formed in the support body and the heater at both end portions in the central axis direction of the hole formed in the support body.

8. Glass sheet manufacturing apparatus according to claim 6 or 7,

and a sealing member is filled between the hole formed in the wall of the forming furnace and the heater.

9. A method for producing a glass sheet, comprising a forming step of forming a glass ribbon from a molten glass by a down-draw method using a forming body housed in a forming furnace and a support body supporting a protruding portion formed at both widthwise end portions of the forming body,

the method for manufacturing a glass sheet is characterized in that,

in the forming step, the support is heated by a heater provided in the support.

Technical Field

The present invention relates to an apparatus and method for manufacturing glass sheets using a down-draw process.

Background

As a typical example of the down-draw method employed in the field of glass sheet production, there is known an overflow down-draw method of continuously forming a glass ribbon while causing molten glass to flow down along both surfaces of a formed body having a substantially wedge-shaped cross section. As another down-draw method, a slit down-draw method or the like is known.

Patent document 1 discloses an apparatus for manufacturing a glass sheet by an overflow downdraw method. Both ends in the width direction (longitudinal direction) of a molded body, which is a component of this apparatus, are supported by support bodies.

Documents of the prior art

Patent document

Patent document 1: WO2012/132309 publication

Disclosure of Invention

Problems to be solved by the invention

Generally, the periphery of the molded body 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 body, heat in the periphery of both ends in the width direction is taken away by the support body.

Therefore, the temperature of the portion of the forming body that contacts the both width-direction end portions of the glass ribbon is reduced as compared with the portion of the forming body that contacts the width-direction central portion of the formed glass ribbon. As a result, the thickness unevenness (thickness unevenness) of the glass plate as a product may be increased and devitrification may occur, and it is difficult to obtain a product of stable quality.

From the above viewpoint, the present invention has an object to reduce the problems of thickness unevenness and devitrification of a glass sheet by maintaining the peripheral temperature of both end portions in the width direction of a molded body at an appropriate temperature.

Means for solving the problems

A first aspect of the present invention made to solve the above problems is a glass sheet manufacturing apparatus that houses a forming body used for forming molten glass into a glass ribbon by a downdraw method and a support body that supports both widthwise end portions of the forming body in a forming furnace, the glass sheet manufacturing apparatus being characterized in that a heater is provided to the support body.

According to this configuration, since the support bodies supporting both widthwise end portions of the molded body are heated by the heater, a decrease in temperature around both widthwise end portions in the molding furnace can be suppressed. Therefore, the temperature difference between the two portions of the forming body, which are the portion in contact with the widthwise central portion of the formed glass ribbon, and the portions of the forming body in contact with the widthwise both end portions of the glass ribbon is reduced. As a result, the thickness unevenness (degree of thickness unevenness) of the glass plate as a product is reduced, and devitrification is less likely to occur, and a product of stable quality can be provided.

In this structure, the support is preferably a refractory brick.

This ensures the strength at high temperature, and prevents deformation of the support body.

In addition to the above configuration, the heater may be disposed in a hole formed in the support body.

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

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

Thus, the heater can be appropriately supported, and the heater can be easily installed and replaced.

In this configuration, the heater may have a rod shape, the hole formed in the support may be a through hole, the hole formed in the furnace wall of the forming furnace may be a through hole, and the heater may penetrate the through holes.

In this way, the heater can be installed from outside the molding furnace and replaced during operation. Further, the heater may be wired while extending outside the molding furnace. Further, the heater can be made elongated by forming the heater into a rod shape. Thus, the through-holes formed in the support body and the furnace wall can be made small in diameter, and the amount of heat dissipated from the inside of the forming furnace can be reduced.

In this configuration, the support body may be formed 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, and therefore the temperature of the ambient gas around both ends in the width direction of the molded body can be increased. Therefore, the temperature difference between the two portions of the forming body, the portion of the forming body that contacts the widthwise central portion of the glass ribbon, and the portions of the forming body that contact the widthwise both end portions of the glass ribbon, is further reduced.

In this configuration, the opening window may be provided in a middle portion in the central axis direction of the hole formed in the support body, and a seal may be filled between the hole formed in the support body and the heater at both end portions in the central axis direction of the hole formed in the support body.

When the opening window is provided, the ambient gas in the molding furnace easily flows out from between the hole of the support body and the heater through the opening window, and accordingly, the temperature in the molding furnace is easily lowered. On the other hand, if the sealing material is filled between the hole of the support body and the heater at both ends in the central axis direction of the hole of the support body, the outflow of the ambient gas in the molding furnace can be prevented, and the temperature in the molding furnace can be appropriately maintained.

In addition to the structure in which the opening window is provided, a sealing member may be filled between the heater and a hole formed in the wall of the forming furnace.

Even in such a case, the outflow of the ambient gas in the molding furnace can be prevented, and the temperature in the molding furnace can be appropriately maintained.

A second aspect of the present invention made to solve the above problems is a method for producing a glass sheet, including a forming step of housing a forming body and support bodies for supporting both width-direction end portions of the forming body in a forming furnace, and forming molten glass into a glass ribbon by a downdraw method using the forming body, wherein the support bodies are heated by heaters provided in the support bodies in the forming step.

In the case of this method, as with the above-described matters, it is difficult to cause problems of thickness unevenness (degree of thickness unevenness) and devitrification of the glass sheet to be a product, and a product of stable quality can be provided.

Effects of the invention

According to the present invention, the peripheral temperature of both ends in the width direction of the molded body can be maintained at an appropriate temperature, and the problems of thickness unevenness and devitrification of the glass sheet can be reduced.

Drawings

Fig. 1 is a vertical sectional side view showing a main part of a glass sheet manufacturing apparatus according to an embodiment of the present invention.

Fig. 2 is a longitudinal sectional front view taken along line a-a of fig. 1.

Fig. 3 is a longitudinal sectional side view taken along line B-B of fig. 2.

Fig. 4 is a longitudinal sectional front view taken along line C-C of fig. 1.

Fig. 5 is a longitudinal sectional side view of the main portion of fig. 1, with one side partially enlarged.

Fig. 6 is a longitudinal sectional front view in which one side portion of the main portion of fig. 2 is enlarged.

Fig. 7 is a longitudinal sectional side view of the main portion of fig. 3, partially enlarged.

Fig. 8 is a longitudinal sectional front view in which one side portion of the main portion of fig. 4 is enlarged.

Detailed Description

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

[ glass plate manufacturing apparatus ]

Fig. 1 is a vertical sectional side view showing a main part of a glass sheet manufacturing apparatus according to an embodiment of the present invention, and fig. 2 is a vertical sectional front view taken along a line a-a of fig. 1. Fig. 3 is a vertical sectional side view taken along line B-B of fig. 2, and fig. 4 is a vertical sectional front view taken along line C-C of fig. 1. As shown in the above figures, the glass sheet manufacturing apparatus 1 includes, as main components, a forming body 2, a pair of support bodies 3, and a forming furnace 4 that houses the forming body 2 and the support bodies 3. The formed body 2 is formed by an overflow down-draw method to form a glass ribbon 6 from a molten glass 5 at its widthwise intermediate portion. The pair of support members 3 are provided to support both ends of the molded body 2 in the width direction. Here, the "width direction" is the left-right direction in fig. 2 and 4, and in the present embodiment, represents the longitudinal direction of the molded body 2.

The forming body 2 has an overflow vessel 7 formed at the top, and a pair of surfaces 8 to which the molten glass 5 overflowing from the overflow vessel 7 flows down. The pair of surfaces 8 are each composed of an upper vertical surface portion 8a and a lower inclined surface portion 8b (see fig. 1 and 4). A pair of vertical surface portions 8a is formed on a rectangular parallelepiped portion 2a of the upper portion of the molded body 2. The pair of inclined surface portions 8b are formed at a tapered portion 2b (see fig. 1) which is formed at a lower portion of the molded body 2 and gradually becomes thinner downward. The molten glass flowing 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 is conveyed downward via a cooling roll or the like outside the figure, and is continuously molded as the glass ribbon 6. The molded body 2 is made of, for example, dense zircon, alumina-based, zirconia-based, or other refractory bricks.

The support body 3 is a rectangular parallelepiped refractory brick. The molded body 2 has rectangular parallelepiped projecting portions 2d at both ends in the width direction and end surface portions 2e on the outer sides in the width direction of the tapered portions 2b (see fig. 2 and 4). The projecting portions 2d are provided to project outward in the width direction from the upper portion of the molded body 2. The protrusions 2d are placed on the upper surface of the support body 3. Thus, the weight of the molded body 2 is received by the pair of support bodies 3. In the present embodiment, the lower end of the protruding portion 2d of the formed body 2 is lower than the upper end of the tapered portion 2b (inclined surface portion 8 b). In other words, the upper end of the support body 3 is lower than the upper end of the inclined surface portion 8b of the molded body 2. The widthwise inner end surface portion 3a of the support body 3 is in contact with the widthwise outer end surface portion 2e of the tapered portion 2b of the molded body 2 (see fig. 2 and 4). The support body 3 is made of refractory bricks such as dense zircon, alumina-zirconia, and mullite.

The wall of the forming furnace 4 comprises: end wall portions 4a that cover widthwise outer sides of the protruding portions 2d of the formed body 2, respectively; side wall portions 4b that cover the front and rear outer sides of both surfaces 8 of the molded body 2, respectively; a top wall 4c covering the upper side of the molded body 2; and a bottom wall portion 4d covering the lower side of the molded body 2. Here, the "front-rear direction" is the left-right direction in fig. 1 and 3, and indicates the thickness direction of the molded body 2. A slit-shaped opening 4e that is long in the width direction is formed in the central portion of the bottom wall portion 4d, and the opening 4e is used for the molten glass 5 that is fused and integrated at the lower end portion 2c of the molded body 2 to pass through (see fig. 1 and 2).

The base body 9 is placed on each of the four corners of the bottom wall 4d of the forming furnace 4. The pair of support bodies 3 are placed on the pair of base bodies 9, respectively. The furnace walls 4a to 4d of the forming furnace 4 are made of a plurality of refractory bricks. The base body 9 is also made of refractory bricks.

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

A plurality of heaters 10 are provided on each of the pair of support bodies 3. In the illustrated example, the heaters 10 are provided at two positions, i.e., an upper layer and a lower layer, of each support body 3 (see fig. 2 and 4). Each heater 10 has a rod shape with a circular cross section, and the heaters 10 are inserted through the through holes 11 formed in the respective support bodies 3. These through holes 11 are formed separately at two locations above and below each support body 3 so as to extend in the front-rear direction. More specifically, the through-holes 11 formed in the upper and lower two locations at the central portion in the front-rear direction of each support body 3 and the through-holes 11 formed in the upper and lower two locations at the both end portions in the front-rear direction separately from these are arranged on the same axis (see fig. 3). In addition, through-holes 12 that communicate with the through-holes 11 of the support body 3 (through-holes 11 at both ends in the front-rear direction) are also formed in the side wall portion 4b of the forming furnace 4. Each heater 10 penetrates the through hole 11 of the support body 3 and the through hole 12 of the side wall portion 4b to extend outward from the side wall portion 4 b.

Although not shown, heaters for heating the molten glass 5 flowing down the both surfaces 8 of the molded body 2 are disposed on the side wall portion 4b of the molding furnace 4 so as not to interfere with the support body 3.

Fig. 5 is a longitudinal sectional side view in which a part of one side of a main portion of fig. 1 is enlarged, and fig. 6 is a longitudinal sectional front view in which a part of one side of a main portion of fig. 2 is enlarged. Fig. 7 is a vertical sectional side view in which a part on one side of a main portion of fig. 3 is enlarged, and fig. 8 is a vertical sectional front view in which a part on one side of a main portion of fig. 4 is enlarged. As shown in the above figures, the support body 3 is formed with an opening window 13 for exposing the two heaters 10 in the internal space 4x of the forming furnace 4.

These opening windows 13 are formed in the middle portion in the central axis direction of the through hole 11 (two portions on both sides of the center in the central axis direction). Specifically, opening windows 13 having a concave shape are formed between the through hole 11 at the center portion in the front-rear direction and the through holes 11 at both end portions in the front-rear direction, respectively, and the through holes 11 communicate with these opening windows 13. These opening windows 13 are formed so as to have a shape in which the length in the front-rear direction gradually increases as the window moves from the upper side to the lower side, and are formed so as not to overlap the molded body 2 (tapered portion 2b) (see fig. 5). The inner edge portions of the opening windows 13 in the front-rear direction are inclined so as to follow the inclined surface portions 8b of the molded body 2, and the outer edge portions of the opening windows 13 in the front-rear direction are formed so as to extend in the vertical direction.

A sealing material 14 is filled between the heater 10 and the through-holes 11 formed at both ends of the support body 3 in the front-rear direction. 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 hole 11 formed at two locations of the support body 3. The sealing material 15 is filled between the through hole 12 formed in the side wall portion 4b of the forming furnace 4 and the heater 10 over the entire circumference of the heater 10. These seals 14, 15 are heat insulating materials, for example made of refractory fibers.

The above description based on fig. 5 to 8 is made only for one side of the main part of the glass sheet manufacturing apparatus 1, but the same description applies to the other side of the main part.

According to the glass sheet manufacturing apparatus 1 having the above configuration, the following operational effects are obtained.

Since the support bodies 3 that support both widthwise end portions of the molded body 2 are heated by the heater 10, a decrease in temperature around both widthwise end portions (particularly, the widthwise outer end surface portion 2e of the tapered portion 2b) in the internal space 4x of the molding furnace 4 can be suppressed. Therefore, the temperature difference between the two portions of the forming body 2 that contact the widthwise central portion of the glass ribbon 6 and the portions of the forming body 2 that contact the widthwise both end portions of the glass ribbon 6 is reduced. As a result, the thickness unevenness (degree of thickness unevenness) of the glass plate to be a product is reduced, and devitrification is less likely to occur, and a product of stable quality can be provided. As described above, although a heater, not shown, is disposed on the side wall portion 4b of the forming furnace 4, this heater cannot sufficiently suppress a decrease in temperature due to heat removal from the support body 3.

Further, since the heater 10 is inserted into the through hole 11 formed in the support body 3, only the heater 10 can be replaced, and maintenance, inspection, management, and the like can be easily performed. Further, since the heater 10 is also inserted into the through hole 12 formed in the side wall portion 4b of the forming furnace 4, the heater 10 can be replaced from the outside of the forming furnace 4, and maintenance, inspection, management, and the like can be further easily performed.

Further, since the opening windows 13 for exposing the heater 10 to the internal space 4x of the molding furnace 4 are formed in the support body 3, the heat from the heater 10 is efficiently transmitted to the internal space 4x of the molding furnace 4 through the opening windows 13. This can further suppress a decrease in temperature around both ends in the width direction of the molded body 2 (particularly, the end surface portion 2e on the outer side in the width direction of the tapered portion 2 b). Further, as shown in fig. 5, since the opening window 13 is not overlapped with the molded body 2 and has a shape in which the length in the front-rear direction gradually increases as it moves from the upper side to the lower side, it is possible to transmit the heat from the heater 10 to the internal space 4x of the molding furnace 4 as much as possible.

In addition, when the opening window 13 is provided, the ambient gas in the forming furnace 4 easily flows out from between the through holes 11 and 2 and the heater 10 through the opening window 13, and accordingly, the temperature in the forming furnace 4 is easily lowered. In contrast, in the glass plate manufacturing apparatus 1 of the present embodiment, the sealing material 14 is filled between the through hole 11 and the heater 10 at both end portions in the central axis direction of the through hole 11 formed in the support body 3. In addition, the sealing material 15 is filled between the heater 10 and the through hole 12 formed in the side wall portion 4b of the forming furnace 4. This prevents the outflow of the ambient gas in the molding furnace 4, and the temperature in the molding furnace 4 can be appropriately maintained.

The glass-plate manufacturing apparatus 1 of the present invention is not limited to the above embodiment, and various modifications can be made as shown below.

That is, although the through-hole 11 is formed in the support 3 in the above embodiment, a hole that does not penetrate may be formed in the support 3. Further, the heater 10 is formed in a rod shape, but the heater 10 may be formed in a shape other than a rod shape. The heater 10 may be embedded in the support 3. The number of heaters 10 for 1 support body 3 is not limited to two, and may be 1, 3 or more, or the heaters 10 may be arranged in a plurality of rows in a vertical direction. In the above embodiment, 1 opening window 13 is configured to expose all the heaters 10 in the upper and lower stages, but a plurality of opening windows 13 may be formed in the upper and lower stages, and these opening windows 13 may expose the heaters 10 in the upper and lower stages one by one. Further, although the through-hole 12 is formed in the side wall portion 4b of the forming furnace 4, a hole that does not penetrate may be formed in the side wall portion 4b, or a hole may not be formed in the side wall portion 4 b. Further, the support 3 is separated from the end wall portion 4a of the forming furnace 4, but the support 3 may be brought into contact with or close to the end wall portion 4 a. In this case, a hole extending in the width direction may be formed in the support body 3, a hole may be formed in the end wall portion 4a, and the heater 10 may be inserted through the holes so as to straddle the holes.

In the above embodiment, the upper end of the support body 3 is lower than the upper end of the inclined surface portion 8b of the molded body 2, but the upper end of the support body 3 may be flush with the upper end of the inclined surface portion 8b or may be higher than the upper end of the inclined surface portion 8 b.

Further, in the above-described 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 present invention is also applicable to a formed body used for forming the molten glass into the glass ribbon by the slit down-draw method and a support body that supports both end portions in the width direction of the formed body.

[ method for producing glass plate ]

Next, a method for producing a glass plate according to another embodiment of the present invention will be described. Referring to fig. 1 to 8, the glass sheet manufacturing method includes a forming step of accommodating a formed body 2 and support bodies 3 that support both ends of the formed body 2 in the width direction in a forming furnace 4, and forming molten glass 5 into a glass ribbon 6 using the formed body 2 by a down-draw method. In the molding step, the support 3 is heated by a heater 10 provided in the support 3. Therefore, even in the case of using this glass plate production method, for the same reason as described above in the glass plate production apparatus 1, the problems of the thickness unevenness (degree of thickness unevenness) and devitrification of the glass plate to be a product are less likely to occur, and a product of stable quality can be provided.

Description of reference numerals:

1 glass plate manufacturing apparatus

2 shaped body

3 support body

4 forming furnace

4a furnace wall (end wall part)

4b furnace wall (side wall part)

Inner space of 4x forming furnace

5 molten glass

6 glass ribbon

10 heater

11 through hole formed in support body

12 through-holes formed in the furnace wall

13 opening window

14 sealing element for a support body

15 sealing of the furnace wall.