KR20110130390A - Molten glass stirring device - Google Patents

Abstract

It is a molten glass stirring apparatus which stirs the said molten glass in the molten glass conveyance pipe which conveys the molten glass of viscosity 100-7000 dPa * s by conveying quantity 1-50m <^3> / hour * S (S is a cross-sectional area of a conveyance pipe), A molten glass stirring apparatus is comprised by the rotatable center axis | shaft and the stirring part provided in the said center axis | shaft, The said stirring part is comprised by the horizontal stirring vane and the vertical stirring vane containing a plate-shaped body, respectively, The said horizontal stirring vane is long A side is orthogonal to the central axis, and a short side is provided at an angle of 10 to 70 degrees in the axial direction of the central axis, and the longitudinal stirring vane is at a position where the long side is parallel to the central axis and defines the outer edge of the stirring portion. installed and, to the diameter of the molten glass conveying tubes in the area in addition the stirring is provided by D ₁ (mm), the stirring portion up to the diameter D ₂ (mm) of the outer edge The molten glass stirring apparatus which satisfy | fills 0.8xD <_1> D < ₂ > = 0.98xD <_1> .

Description

Molten glass stirring device {DEVICE FOR STIRRING MOLTEN GLASS}

This invention melts which stirs molten glass in the molten-glass conveyance tube with a high conveyance amount of molten glass, such as the plate glass manufacturing apparatus for large flat panel displays (FPD), among the molten glass conveyance tubes which convey a molten glass especially. It relates to a glass stirring device.

Conventionally, in order to improve the homogeneity of a molten glass, stirring a molten glass is provided by installing a stirring apparatus in the molten glass conveyance pipe which conveys a molten glass. Homogeneity of a molten glass greatly influences transparency, thickness, etc. of the glass produced.

A stirring device is comprised from the stirring part which has a central axis used as a rotation center generally, and the stirring blade provided around it.

In order to fully homogenize the molten glass conveyed, when stirring the molten glass which passes through the inside of a molten glass conveyance pipe with a stirring apparatus, it is necessary to prevent the phenomenon which a molten glass escapes through a stirring apparatus, what is called "falling out". . Since the molten glass which has passed out is not sufficiently stirred, many so-called "heterogeneous components" which became components different from the component of a molten glass by reaction with the brick and gaseous phase which comprise a molten-glass conveyance pipe are contained, and it melts When the glass solidifies and becomes a glass product, the foreign component becomes an opaque stripe defect called a rim. That is, in order to homogenize a molten glass, it is necessary to prevent disengagement and to diffuse a heterogeneous component in a molten glass by fully stirring a molten glass.

Patent Literature 1 proposes a stirring device in which a plurality of convex portions are arranged on the outermost side of a stirring blade for narrowing the distance between the wall surface and the stirring blade, for the purpose of reducing the molten glass that does not stir along the wall surface of the flow path. have. However, this stirring device is still insufficient to prevent the escape from the vicinity of the wall surface of the flow path, and it is easy to cause the escape around the central axis of the stirring device. Therefore, the stirring effect of the molten glass is not sufficient. .

The stirring device disclosed in patent document 2 makes stirring blades provided around the central axis into long stirring blades and single stirring blades with different rotation radii, for the purpose of improving the homogeneity of the molten glass. However, the installation of two or more stirring blades alternately is described. However, even with this stirring device, the effect of preventing the escape from the vicinity of the wall surface of the flow path and around the central axis of the stirring device is not sufficient.

Moreover, as a means of stirring molten glass for the purpose of improving homogeneity, the molten glass stirring blade of patent document 3 mentioned later also exists.

Japanese Patent Laid-Open No. 2001-72426 Japanese Patent Publication No. 2003-63829 Japanese Patent Laid-Open No. 10-265226

In recent years, glass substrates for large-sized FPDs, in particular, require a mixture of unmelted raw materials, high transparency, and high flatness, so that glass with few defects and high homogeneity has been desired.

In addition, high homogeneity is also required in glass for applications requiring high transparency such as optical lenses, optical communication fibers, optical filters, solar cell substrates, and fluorescent tubes.

When such a very high homogeneity is required, it becomes difficult for the molten glass to obtain sufficient homogeneity with the conventional stirring apparatus.

In order to solve the above problems, the present invention can prevent the escape of the molten glass in the stirring apparatus, more specifically, the escape of the molten glass in the vicinity of the conveying pipe wall surface and around the central axis of the stirring apparatus, Moreover, it aims at providing the glass stirring apparatus which was excellent in the stirring effect of the molten glass in a molten glass conveyance pipe.

MEANS TO SOLVE THE PROBLEM This invention melt | dissolves in the molten-glass conveyance pipe which conveys the molten glass of viscosity 100-7000dPa * s by conveying quantity 1-50m <^3> / hour * S (S is the cross-sectional area of a conveyance pipe) in order to achieve said objective. It is a molten glass stirring apparatus which stirs glass, The said molten glass stirring apparatus is comprised by the rotatable central axis and the stirring part provided in the said central axis, The said stirring part is a horizontal stirring vane and a vertical stirring vane containing a plate-shaped body, respectively. The transverse stirring blade is provided with a long side perpendicular to the central axis, a short side inclined 10 to 70 degrees in the axial direction of the central axis, and the longitudinal stirring vane has a long side parallel to the central axis. , is provided at the position which defines the outer edge of said stirring, wherein the stirring portion of the diameter of the molten glass feed pipe D ₁ (mm) in a region that is installed, the stirring portion When referred to the maximum diameter of the outer border group D ₂ (mm), and provides the molten glass stirring device that satisfies _{0.8 × D 1 ≤D 2 ≤0.98 ×} D 1.

Moreover, this invention is a plate glass manufacturing apparatus which has a glass melting apparatus, a plate glass forming apparatus, and the molten glass conveying tube provided between the said glass melting apparatus and the said plate glass forming apparatus, The melting of this invention mentioned above to the said molten glass conveying tube Provided is a plate glass manufacturing apparatus in which at least one glass stirring device is provided.

Moreover, this invention provides the molten glass stirring method using the molten glass stirring apparatus of this invention.

Moreover, this invention provides the plate glass manufacturing method using the plate glass manufacturing apparatus of this invention.

The glass stirring apparatus of this invention can prevent the escape of the molten glass in a stirring apparatus, More specifically, the escape of the molten glass in the vicinity of a molten glass conveyance pipe wall surface, and the periphery of the central axis of a stirring apparatus, In particular, since the stirring action of the molten glass in the molten glass conveying tube is excellent and the homogeneity of the molten glass after stirring is excellent, the homogeneity is particularly suitable for a glass substrate for FPD having a large size (for example, one side of 2 m or more). You can get the glass. As a result, there is no mixture of unmelted raw materials, high transparency, and high glass with high flatness.

Moreover, since the glass stirring apparatus of this invention is excellent in the homogeneity of the molten glass after stirring, glass manufacture of the use which requires high transparency, such as an optical lens, an optical communication fiber, an optical filter, a solar cell substrate, and a fluorescent tube, is demanded. It is also suitable to make with a molten glass stirring device of the device.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows a part of glass stirring apparatus of this invention.
FIG. 2 is a plan view of the glass stirring device shown in FIG. 1. FIG.
FIG. 3 is a side view of the glass stirring device shown in FIG. 1. FIG.
4 is a schematic view of a molten glass carrier tube used in Example 1. FIG.
5 is a side view of the glass stirring device of Comparative Example 1. FIG.
6 is a perspective view of a glass stirring device of Comparative Example 2. FIG.
7 is a side view of a glass stirring device of Comparative Example 3. FIG.
The schematic diagram which shows the behavior of the fluid in the molten-glass conveyance tube in Example 1. FIG.
9 is a schematic diagram showing the behavior of a fluid in a molten glass carrier tube in Comparative Example 1. FIG.
The schematic diagram which shows the behavior of the fluid in the molten-glass conveyance pipe in the comparative example 2. FIG.
It is a schematic diagram which shows the behavior of the fluid in the molten glass conveyance pipe in the comparative example 3. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, the glass stirring apparatus of this invention is demonstrated with reference to drawings.

The size of the glass substrate for FPD advances year by year, and as the demand increases, it is increasingly required to produce the said glass substrate in large quantities. In the facility which manufactures the plate glass for FPD, the conveyance amount of molten glass is calculated | required. Also in the installation which manufactures glass for uses, such as an optical lens, an optical communication fiber, an optical filter, a solar cell board | substrate, and a fluorescent tube, the increase of the conveyance amount of molten glass is calculated | required.

As a method of increasing the conveyance amount of the molten glass in a molten glass conveyance tube, there are a method of increasing the cross-sectional area of a molten glass conveyance tube, and the method of increasing the flow velocity of the molten glass in a molten glass conveyance tube.

However, it is not preferable to extremely increase the cross-sectional area of the molten glass carrier tube because it increases the equipment cost. Moreover, when increasing the flow velocity of the molten glass in a molten glass conveyance pipe, the escape | flow of the molten glass in a stirring apparatus tends to occur, and the stirring effect of a molten glass will fall easily.

It is preferable to install and use the glass stirring apparatus of this invention in the molten-glass conveyance pipe with a high conveyance amount of such molten glass, Specifically, melt | dissolution of viscosity 100-7000 dPa * s, Preferably viscosity 200-6000 dPa * s It is installed and used in a molten glass conveyance pipe which conveys glass in conveying quantity 1-50m <^3> / hour * S, Preferably conveying quantity 2-50m <^3> / hour * S (S is cross-sectional area of a conveyance pipe).

FIG. 1: is a perspective view which shows a part of glass stirring apparatus of this invention, FIG. 2 is a top view of the said glass stirring apparatus, and FIG. 3 is a side view of the said glass stirring apparatus.

The glass stirring apparatus 1 shown to FIGS. 1-3 has the center axis | shaft 10 which can be rotated, and the stirring part 20 is provided in the lower end part of the said centershaft 10. As shown in FIG.

The stirring part 20 is comprised from the vertical stirring blade 30 and the horizontal stirring blade 40 which consist of plate bodies, respectively.

The longitudinal stirring blade 30 which consists of a plate-shaped body is provided in the position which the long side is parallel to the central axis 10, and defines the outer edge of the stirring part 20. As shown in FIG. In other words, the horizontal stirring blade 40 is positioned between the parallel central axis 10 and the vertical stirring blade 30.

The longitudinal stirring blade 30 has a function which mainly stirs a molten glass, while preventing the molten glass from escaping mainly in the molten-glass conveyance pipe wall surface vicinity.

It is preferable that the vertical stirring blade 30 has the support structures 30a and 30b extended in the direction of the central axis 10 from the upper and lower ends in terms of the supporting strength of the vertical stirring blade 30.

Therefore, when the support strength of a vertical stirring blade is obtained, the support structures 30a and 30b may not be necessary. In this case, the vertical stir blade 30 is indirectly supported by the central axis 10 via the horizontal stir blade 40.

However, it is preferable to have at least one of the support structures 30a and 30b.

In addition, the support structures 30a and 30b vertically stir the support structures corresponding to (30a and 30b) which are provided in parts other than the upper and lower ends of the vertical stirring vanes 30 (such as the middle portion of the vertical stirring vanes 30). Although it is possible to provide in the intermediate | middle part of the blade | wing 30, in consideration of the stirring function of a molten glass, it is preferable to provide it in the upper and lower ends of the vertically stirring blade 30.

Although the glass stirring apparatus 1 shown in FIGS. 1-3 has four longitudinal stirring vanes 30, the number of the vertical stirring vanes in the glass stirring apparatus 1 of this invention is not limited to this. However, in order to exhibit the effect of preventing the escape of molten glass in the vicinity of a molten glass carrier pipe wall surface, it is preferable to provide at least two longitudinal stirring vanes so that it may become a position which opposes with respect to the central axis 10.

On the other hand, when the number of longitudinal stirring blades is too large, eight or less pieces are preferable from the reason that the stirring of a molten glass rather inhibits, and the torque required for rotation of a stirring part increases.

Therefore, it is preferable that the number of vertical stirring blades is 2-8 pieces, More preferably, it is 3-6 pieces.

The dimension of the vertical stirring blade 30 is suitably selected according to the dimension of the molten glass conveyance pipe which installs a glass stirring apparatus, and the viscosity and conveyance amount of the molten glass conveyed. However, the vertical agitation maximum diameter D ₂ of the outer rim of the stirring portion 20 is determined by the installation position of the blade 30, the diameter of the feed pipe 100 in the region where the glass stirring device 1 is installed It is necessary to satisfy the following equation 1 in relation to D ₁ .

By satisfy | filling said Formula (1), the function which prevents the escape | emission of the molten glass in the vicinity of a molten-glass conveyance pipe wall surface can fully be exhibited, and the contact of the vertical stirring blade 30 and the molten-glass conveyance pipe wall surface can be prevented. .

Moreover, at the time of using the glass stirring apparatus of this invention, it is preferable that the distance of the molten glass conveyance pipe wall surface and the outer edge of the stirring part 20 is constant.

It is preferable that it is 0.85 * D <_1> D <_2> , and, as for the point of the act of preventing the escape | emission of molten glass in the molten glass conveyance pipe wall surface vicinity, it is more preferable that it is 0.9 * D <_1> D <_2> .

Vertical stirring long wings 30, a side length L, the stirring portion 20, the relationship between the maximum diameter D ₂ of the outer border and the molten glass feed pipe glass stirring device 1, the installable area of the 100 of the It is suitably selected according to the length, the viscosity of the molten glass conveyed, or the conveyance amount.

In addition, when viewed from the outer edge up to the relationship between the diameter D ₂ of the stirring portion 20, the long side length L of the vertical stirring blade 30, it is preferable to satisfy 0.5 × D ₂ × D ₂ ≤L≤3 It is more preferable to satisfy D ₂ ≤ L ≤ 2.5 x D ₂ , and even more preferably 1.2 x D ₂ ≤ L ≤ ₂ x D ₂ .

A vertical stirring blade 30, the short side width W, the dimensions of the different components of the glass stirring device 1, specifically, the stirring portion 20, maximum diameter D _2, the central axis 10 of the outer rim of the diameter D _3, or is suitably selected depending on the viscosity and amount of conveying relationships and, conveyed the molten glass to the length of the horizontal stirring blade (40).

Further, to satisfy the relationship when viewed from the outer edge up to the diameter D ₂ of the stirring unit 20, a vertical stirring shorter side width W of the blade 30 is, 0.01 × D ₂ × D ₂ ≤W≤0.2 It is preferable to satisfy 0.05 × D ₂ ≦ W ≦ 0.15 × D ₂ , more preferably 0.07 × D ₂ ≦ W ≦ 0.15 × D ₂ .

The width | variety of the outer end surface and inner end surface of the vertical stirring blade 30 is made into the thickness t of the vertical stirring blade 30. As shown in FIG. The thickness t of the vertical stirring blade 30 is a relationship with the maximum diameter D ₂ of the outer edge of the stirring part 20, and the other dimension of the vertical stirring blade 30, specifically, the length of the vertical stirring blade 30. It selects suitably according to L and width W, the constituent material of the vertical stirring blade 30, and the viscosity and conveyance amount of the molten glass conveyed.

In addition, when seen from the relationship of the maximum to the diameter D ₂ of the outer rim of the stirring portion 20, the thickness t of the vertical stirring blade 30, it is preferable to satisfy 0.01 × D ₂ × D ₂ ≤t≤0.3 It is more preferable to satisfy 0.03 x D ₂ ≤ t ≤ 0.2 x D ₂ , and more preferably 0.05 x D ₂ ≤ t ≤ 0.15 x D ₂ .

In addition, the constituent material of the vertical stirring blade 30 will not be specifically limited if it is a material with heat resistance and erosion resistance with respect to a molten glass, It is preferable to use the platinum or platinum rhodium alloy which is excellent in heat resistance. In order to improve the strength, molybdenum having a high melting point is used as the core material, a material coated with alumina on the molybdenum core material, and a platinum or platinum rhodium alloy coated thereon can also be used. About this point, the same also applies to the other components of the glass stirring apparatus, ie, the central axis 10 and the horizontal stirring blade 40.

The horizontal stirring blade 40 which consists of a plate-shaped object is located between the central axis 10 and the vertical stirring blade 30. The long side of the horizontal stirring blade 40 is perpendicular to the central axis 10, and the short side thereof is inclined with respect to the axial direction of the central axis 10. Hereinafter, in this specification, the side orthogonal to the central axis 10 is made into the long side among the two sides which the horizontal stirring blade 40 which consists of a plate body has, and the side orthogonal to the said long side is made into the short side. . Therefore, depending on the shape of the transverse stirring blade, the relationship between the apparent long side and the short side and the relationship between the long side and the short side in the present invention may be reversed. In addition, the short side of the horizontal stirring blade 40 is inclined with respect to the axial direction of the central axis 10, The "horizontal stirring blade is inclined with respect to the central axis".

The transverse stirring blade 40 prevents from escaping around the central axis 10 side, particularly around the central axis 10, rather than the longitudinal stirring blade 30, and passes through the site where the stirring unit 20 is installed. It has the function of increasing the residence time of the molten glass. Thereby, the function of stirring the molten glass by the center axis | shaft 10 side rather than the vertical stirring blade 30 improves.

In order to exhibit the above two functions, the inclination angle α of the horizontal stirring blade 40 with respect to the central axis 10 is 10 to 70 degrees, preferably 30 to 60 degrees, more preferably 40 to 50 degrees. .

In the glass stirring apparatus 1 shown in FIGS. 1-3, four horizontal stirring blades 40 are provided between the center axis | shaft 10 and the vertical stirring blade 30 at intervals up-down, but this invention In the glass stirring device 1 of the present invention, the number of horizontal stirring blades provided between the central axis 10 and the vertical stirring blades 30 is not limited to this, for example, the central axis 10 and the vertical stirring. Only one horizontal stirring blade 40 may be provided between the blades 30, and 5 or more horizontal stirring blades 40 may be provided. However, when the horizontal stirring blade provided between the central axis 10 and the vertical stirring blade 30 increases, since the torque required to rotate the stirring part 20 increases accordingly, it is preferable that it is eight pieces or less. Therefore, it is preferable that the number of the horizontal stirring blades provided between the central axis 10 and the vertical stirring blades 30 is 1-8 pieces.

In order to prevent the increase in the torque required to rotate the stirring section 20, the interval between the horizontal stirring vanes 40 provided between the central axis 10 and the vertical stirring vanes 30 is not so narrowed. It should be noted that When paying attention to the side shape of the stirring part 20 shown in FIG. 3, the space | gap part (namely, in the area | region enclosed by the central axis 10, the vertical stirring blade 30, and the support structures 30a, 30b) When the ratio of the part which does not exist the horizontal stirring blade 40 becomes small, since the torque required to rotate the stirring part 20 increases, it is unpreferable.

In terms of preventing increase in torque required to rotate the stirring section 20, the area of the area enclosed by the central axis 10, the longitudinal stirring blades 30, and the supporting structures 30a and 30b (i.e., horizontally) There exists a horizontal stirring blade 40 occupied by the area S ₁ (S ₁ = i × h) of the portion where the stirring blade 40 exists and the area S ₂ (S ₂ = i × j) of the void portion. is the ratio of the area S ₁ of the portion _{((S 1 / (S 1} + S 2))) is preferably from 20 to 60%, more preferably not less than 80% or less is preferable, and 60% is more preferred to.

Length i of the horizontal stirring blade 40, the dimensions of the different components of the glass stirring device 1, specifically, the diameter of the stirring portion 20 is outside border maximum diameter D _2, the central axis 10 of the D ₃ , it is suitably selected according to the relationship with the width W of the vertical stirring blade 30.

Horizontal stirred height h of the blade 40, the above-described _{(S 1 / (S 1 +} S 2)) relationship, or the inclination angle of the horizontal stirring blade (40) α, in accordance with the viscosity or the conveying amount of the molten glass to be transported in Appropriately selected.

The thickness of the horizontal stirring blade 40 is another dimension of the horizontal stirring blade 40, specifically, the length i and height h of the horizontal stirring blade 40, the constituent material of the horizontal stirring blade 40, and being conveyed It selects suitably according to the viscosity and conveyance amount of a molten glass. When viewed from the relationship with the length i of the horizontal stirring blade 40, when the material of the above-mentioned material of the horizontal stirring blade 40 is the above-mentioned material, it is preferable that it is 0.005xi <= thickness <0.4xi, and 0.01xi <= thickness It is more preferable that it is ≤ 0.2 x i, and it is further more preferable that it is 0.015 x i ≤ thickness ≤ 0.1 x i.

In the glass stirring apparatus 1 shown to FIGS. 1-3, in order to improve the stirring effect of molten glass, the structure (vertical stirring blade 30 and horizontal stirring blade 40) provided in the outer periphery of the central axis 10 is shown. In order to increase the supporting strength of), the portion constituting the stirring portion 20 of the central axis 10 is expanded in diameter.

However, it should be noted that as the diameter of the central shaft 10 increases, the torque required to rotate the stirring section 20 increases. Moreover, when the diameter of the center axis | shaft 10 becomes large, the area | region enclosed by the center axis | shaft 10 of FIG. 3, the vertical stirring blade 30, and the support structures 30a and 30b becomes narrow. Since the molten glass which passes the central axis 10 side rather than the vertical stirring blade 30 in this area is stirred, when this area becomes too narrow, since the stirring function of the molten glass by the horizontal stirring blade 40 will rather fall, it is preferable. Not.

For the above reason, the maximum diameter D ₂ (mm) of the outer edge of the stirring part 20 and the diameter of the central axis 10 (more specifically, the lower end part which comprises the glass stirring part 20 among the central axis 10). diameter in the vicinity of) D ₃ (mm) the D ₃ ≤0.6 × D ₂ is preferable, and D ₃ ≤0.5 × D ₂ is more preferred, and more preferably D ₃ ≤0.45 × D _2.

However, when the diameter of the central axis 10 is too small, there is a fear that the central axis is damaged by the stress at the time of turning. In view of this, in the case where the constituent material of the central axis 10 is the above-described material, the maximum diameter D ₂ (mm) of the outer edge of the stirring section 20 and the diameter of the central axis 10 (more specifically, the central axis 10 of the diameter of the vicinity of the lower edge of the glass constituting the agitating part (20)) D _3, it is preferable to satisfy D ₃ ≥0.1 × D _2.

In patent document 3, the 2nd flat plates 5 and 6 inclined at the angle (theta) 2 with respect to the axial direction of the rotating shaft 9, the 1st flat plates 3 and 4, the 3rd flat plates 7 and 8, and the rotating shaft 9. The molten glass stirring blade 1 which has the is disclosed (refer FIG. 6 here).

The molten glass stirring blade of the same document aims at stirring in a small scale continuous furnace, and it stirs the molten glass with a small flow volume, ie, hold | maintained in some time melting tank.

And the 2nd flat plates 5 and 6 incline with the angle (theta) 2 with respect to the axial direction of the rotating shaft 9 in order to push up the molten glass hold | maintained in a melting tank to the upper side of the said melting tank.

On the other hand, the glass stirring apparatus of this invention is installed and used in the molten glass conveyance pipe which conveys the molten glass of viscosity 100-7000dPa * s by conveying quantity 1-50m <^3> / hour * S (S is the cross-sectional area of a conveyance pipe). Therefore, a vertical stirring blade prevents the escape of the molten glass in the conveyance pipe wall surface vicinity, and stirs the molten glass of the molten glass conveyance pipe wall surface vicinity.

Therefore, it should not push up a molten glass to the upper side like 2nd flat plates 5 and 6 disclosed by patent document 3. As shown in FIG.

Moreover, as for the molten-glass stirring blade of patent document 3, the dimension of about 2/3 is preferable for the outer edge position (width dimension I shown in FIG. 2 of the same document) with respect to the inner diameter of a dissolution tank. When width dimension I is made larger than the said suitable range, there exists a possibility that the 2nd flat plates 5 and 6 inclined with respect to the axial direction of the rotating shaft 9 may contact the inner wall of a dissolution tank.

Therefore, in the molten glass stirring blade of patent document 3, the escape effect of the molten glass in the vicinity of a molten-glass conveyance pipe wall surface, and the stirring effect of a molten glass cannot be acquired.

Next, the molten glass stirring method of this invention is demonstrated. In the stirring method of the molten glass of this invention, as shown in FIG. 4, the glass stirring apparatus 1 of this invention is installed in the molten glass conveyance pipe with which molten glass is conveyed, and the molten glass in the said molten glass conveyance pipe is Stir.

Although the application object of this invention is not specifically limited, It applies to the molten glass conveying pipe which conveys the molten glass of viscosity 100-7000dPa * s by conveying quantity 1-50m <^3> / hour * S (S is the cross-sectional area of a conveying pipe). It is preferable.

Moreover, since the molten glass after stirring is excellent in homogeneity, the stirring method of the molten glass of this invention is homogeneous like a glass substrate for FPD, an optical lens, an optical communication fiber, an optical filter, a solar cell substrate, and a fluorescent tube. It is preferable to apply to the stirring of the molten glass which is performed in the process of manufacturing the glass of the use with very strict requirements.

In the molten glass stirring method of this invention, the stirring conditions of a molten glass are not specifically limited, The structure of the glass stirring apparatus to be used (the number of vertical stirring blades and the number of horizontal stirring blades, etc.) and the dimension of each part of a glass stirring apparatus, glass What is necessary is just to select suitably according to the dimension of the molten glass conveying pipe which installs a stirring apparatus, and the conditions (viscosity of molten glass, conveyance amount, etc.) regarding the molten glass conveyed inside the molten glass conveying pipe.

Next, the plate glass manufacturing apparatus of this invention is demonstrated. The plate glass manufacturing apparatus is a glass melting apparatus which melt | dissolves a glass raw material into a molten glass, and the plate glass forming apparatus which shape | molds a molten glass and sets it as plate glass with a minimum structure, for example, the shaping | molding apparatus by the float method or the downdraw method. ) And a molten glass carrier tube provided between the glass melting apparatus and the plate glass molding apparatus for the purpose of conveying the molten glass obtained by the glass melting apparatus to the plate glass molding apparatus. The plate glass manufacturing apparatus usually has components other than a glass melting apparatus and a plate glass forming apparatus. There exists a vacuum degassing apparatus for clarifying a molten glass, as an example of components other than these. And in order to convey a molten glass between these components, the plate glass manufacturing apparatus has a some molten glass conveyance pipe normally. In the plate glass manufacturing apparatus of this invention, the glass stirring apparatus of this invention mentioned above is provided in any one or several of these molten glass conveyance tubes which exist. In the plate glass manufacturing apparatus of this invention, the position which installs the glass stirring apparatus of this invention is not specifically limited. Therefore, you may provide the glass stirring apparatus of this invention in any molten glass conveyance pipe which comprises a plate glass manufacturing apparatus. Moreover, the number of the glass stirring apparatus to install is not specifically limited, either. However, when a plate glass manufacturing apparatus includes a vacuum degassing apparatus as a component, the glass stirring of this invention is carried out in at least one of the molten-glass conveying pipe of the upstream of a vacuum degassing apparatus, and the molten glass conveying pipe of the downstream of a vacuum degassing apparatus. It is preferable to provide a high homogeneity plate glass, and it is preferable to provide an apparatus, and the glass stirring apparatus of this invention is provided in both the molten-glass conveyance pipe of the upstream of a vacuum degassing apparatus, and the molten glass conveyance pipe of the downstream of a vacuum degassing apparatus. It is more preferable to install. Moreover, since the torque fluctuation of rotation of a stirring blade is monitored and installed by a torque measuring device, since the deformation | transformation, damage, etc. of a stirring blade or a conveying pipe can be grasped in advance, it is preferable.

Although the plate glass manufacturing apparatus of this invention is applicable to manufacture of the plate glass of various uses, it is especially preferable to apply to manufacture of the plate glass of the use with very high demand for homogeneity like the glass substrate for FPD.

By producing a plate glass using the plate glass manufacturing apparatus of this invention, the plate glass which is free of the mixture of an unmelted raw material, and has high transparency and high flatness is obtained.

Example

In the following example and the comparative example, the model test (experiment using the fluid which simulated molten glass) was performed about the stirring effect of the molten glass conveyed in the molten glass conveyance pipe. FIG. 4: is a schematic diagram of the molten glass conveyance tube used by the model test, and is shown in the state which the glass stirring apparatus 1 shown in FIGS. 1-3 is arrange | positioned in a molten glass conveyance tube (however, it shows typically. Therefore, the shape does not necessarily coincide with FIG. 3). In the model test, the fluid moves in the direction of the arrow in the figure. The dimension of the molten glass conveyance tube shown in FIG. 4 is as follows.

Diameter (both main and branch): 40 mm

Height from the main pipe lower surface to the upper surface of the branch pipe (left): 50 mm

Height from the lower surface of the main pipe to the upper surface of the branch pipe (right): 100 mm

In addition, the conditions regarding the fluid conveyed in the said molten glass conveyance pipe are as follows.

Viscosity: 400dPas

Carriage: 30 m ³ / hour, S

Example 1

The behavior of the fluid at the time of inserting and stirring the glass stirring device 1 of this invention shown to FIGS. 1-3 in the conveyance pipe was evaluated. The dimension of each part of a glass stirring apparatus is as follows.

Maximum diameter D ₂ : 38mm of the outer edge of the stirring section 20

Diameter of the central shaft 10 (part constituting the stirring portion 20) D ₃ : 10 mm

Length L of the vertical stirring blade 30: 60mm

Width W of the vertical stirring blade 30: 3.8mm

Thickness t of the vertical stirring blades 30: 3.8mm

Inclination angle α: 60 degrees of the horizontal stirring blade 40 with respect to the central axis 10

Length of transverse stirring blade 40 i: 10.2mm

Height h of the transverse stirring blade 40: 8 mm

Thickness of horizontal stirring blade 40: 2mm

Area of the area enclosed by the central axis 10, the longitudinal stirring blades 30 and the support structures 30b and 30c (that is, the area S ₁ of the portion where the horizontal stirring blades 40 are present and the area of the portion of the void) the sum of S ₂₎ (the ratio of the area S ₁ of the portion 40) is present _{(S 1 / (S 1 +} S 2) occupied by a horizontal stirring blade): 30%

The glass stirring apparatus 1 inserted the lower end part of the stirring part 20 to the position which becomes 20 mm in height from the center of the branch pipe (left side), and it rotated at the rotation speed of 10 rpm.

8 is a diagram schematically illustrating the behavior of a fluid during stirring. As apparent from FIG. 8, according to the glass stirring device of the present invention, it is possible to effectively prevent the fluid from escaping in the vicinity of the molten glass carrier tube wall surface and around the central axis. As a result, the fluid simulating molten glass is cut by the stirring action (symbol 100), gradually stretched (symbol 200) and flows downstream.

Comparative Example 1

The glass stirring apparatus 1'a shown in FIG. 5 was used. The glass stirring apparatus 1'a shown in FIG. 5 is the same as that of the glass stirring apparatus 1 of an Example except that the horizontal stirring blade 40 does not exist. 9 is a diagram schematically showing the behavior of a fluid during stirring. As apparent from FIG. 9, according to the glass stirring device 1 ′ a of Comparative Example 1, the escape of the fluid in the vicinity of the conveying pipe wall surface can be prevented, but near the center of the conveying pipe (the central axis of the stirring device). Out of the fluid occurred. As a result, the fluid simulating the molten glass was not cut and flowed downstream as it was.

Comparative Example 2

The glass stirring apparatus 1'b shown in FIG. 6 was used. The glass stirring apparatus 1'b shown in FIG. 6 is the same shape as the molten glass stirring blade shown by FIG. 1 of patent document 3. As shown in FIG. The dimension of each part of the glass stirring apparatus 1'b shown in FIG. 6 is as follows.

Diameter of central axis 10 ': 10 mm

Length of stirring blade 30 '(equivalent to the second publication) 10 mm

Width of stirring blade (30 '): 12.5mm

Thickness of the stirring blade 30 ': 3mm

Tilt angle of stirring vanes 30 'with respect to central axis 10': 45 degrees

Length of stirring blade 40 '(corresponding to the first flat plate and third flat plate of the publication): 7 mm

Height of the stirring blade (40 '): 3mm

Thickness of stirring blade (40 '): 2mm

Tilt angle of stirring blade 40 'with respect to central axis 10: 45 degrees

It is a figure which shows typically the behavior of the fluid at the time of stirring. As apparent from FIG. 10, the glass stirring device 1 ′ b of Comparative Example 2 has a stirring action of a fluid near the center of the conveying pipe (around the central axis of the stirring device), and the fluid simulating the molten glass Although it cut | disconnected (symbol 100) and extended gradually (symbol 200), it was not possible to prevent the fluid from escaping near the carrier pipe wall surface.

Comparative Example 3

The glass stirring apparatus 1'c shown in FIG. 7 was used. The glass stirring apparatus 1'c shown in FIG. 7 is the same shape as the homogenizing apparatus shown by FIG. 1 of patent document 1. As shown in FIG. The dimension of each part of the glass stirring apparatus 1'c shown in FIG. 7 is as follows.

Diameter of central axis 10 ': 10 mm

Length (vertical direction) of the stirring blade 30 "(equivalent to the stirring blade 12 of the same publication): 60mm

Length (the horizontal direction) of the stirring blade 30 ": 19mm

Thickness of stirring blade (30 "): 3.8mm

Length of the inclined member 40 ″: 17.6 mm

Thickness of inclined member 40 ″: 3.8 mm

Inclination angle of the inclined member 40 ″ with respect to the central axis 10 ': 60 degrees

Length of the convex part 50: 7mm

Height of the convex part 50: 5mm

In addition, although the long axis of the inclined member 40 ″ is inclined with respect to the central axis 10 ', the short axis thereof is not inclined with respect to the central axis 10'.

It is a figure which shows typically the behavior of the fluid at the time of stirring. As apparent from Fig. 11, according to the glass stirring device 1'c of Comparative Example 3, the escape of the fluid near the conveying pipe wall surface is already prevented, but near the center of the conveying pipe (the central axis of the stirring device). The stirring action of the fluid of the surrounding) fell. As a result, the fluid which simulated the molten glass was cut | disconnected (symbol 100), but it flowed out as it was without extending | stretching downstream (symbol 300).

Example 2

As an example of plate glass manufacture, plate glass is manufactured using the plate glass manufacturing apparatus which has a glass melting apparatus, a 1st molten glass conveying pipe, a vacuum degassing apparatus, a 2nd molten glass conveying pipe, and a float molding apparatus. The glass stirring apparatus 1 of this invention shown in FIGS. 1-3 is provided in the 1st and 2nd molten glass conveyance pipe.

The glass raw material is heated and melted with a glass melting apparatus to obtain a molten glass. The molten glass passes through a 1st molten glass conveyance pipe, a vacuum degassing apparatus, a 2nd molten glass conveying pipe, and a float molding apparatus in this order, and is shape | molded by plate glass. The molten glass is agitated by the glass stirring device of the present invention in the process of conveying the first and second molten glass conveying tubes to improve homogeneity, and there is no mixing of unmelted raw materials, high transparency, and high flatness. Is obtained.

Although this application was detailed also demonstrated with reference to the specific embodiment, it is clear for those skilled in the art that various changes and correction can be added without deviating from the mind and range of this invention.

This application is based on the JP Patent application (Japanese Patent Application No. 2009-047224) of an application on February 27, 2009, The content is taken in here as a reference.

1, 1'a, 1'b, 1'c: glass stirring device
10, 10 ′: central axis
20: glass stirring
30: vertical stirring wing
30a, 30b: support structure
40: horizontal stirring wing
30 ′, 30 ″, 40 ′: stirring blade
40 ″: inclined member
50: convex
100: return tube

Claims (6)

It is a molten-glass stirring apparatus which stirs the said molten glass in the molten-glass conveyance pipe which conveys the molten glass of viscosity 100-7000 dPa * s by conveying quantity 1-50m <^3> / hour * S (S is the cross-sectional area of a conveyance pipe), Molten glass stirring device,
Rotatable central axis,
It is composed of a stirring unit installed on the central axis,
The stirring portion is composed of a horizontal stirring blade and a vertical stirring blade, each containing a plate-like body,
The transverse stirring blade is provided with a long side orthogonal to the central axis, a short side inclined 10 to 70 degrees in the axial direction of the central axis,
The longitudinal stirring vane is provided at a position where the long side defines the outer edge of the stirring portion in parallel with the central axis,
When the diameter of the agitating portion is the molten glass conveying tubes in the region in the installation as D ₁ (mm), the stirring portion up to the diameter D ₂ (mm) of the outer rim,
0.8 × D ₁ ≤D ₂ ≤0.98 × D ₁
Molten glass stirring apparatus that satisfies. The diameter of the central axis is D ₃ (mm),
D ₃ ≤0.6 × D ₂
Molten glass stirring apparatus that satisfies. It is a plate glass manufacturing apparatus which has a glass melting apparatus, the plate glass forming apparatus, and the molten glass conveying pipe provided between the said glass melting apparatus and the said plate glass forming apparatus,
The plate glass manufacturing apparatus in which at least one molten glass stirring device of Claim 1 or 2 was provided in the said molten glass conveyance pipe. 4. The first melting according to claim 3, further comprising a vacuum degassing apparatus provided between the glass melting apparatus and the plate glass forming apparatus, wherein the molten glass carrier tube is provided between the glass melting apparatus and the vacuum degassing apparatus. The molten glass stirring device which consists of a glass conveying pipe and the 2nd molten glass conveying pipe provided between the said vacuum degassing apparatus and the said plate glass forming apparatus, and the said molten glass stirring apparatus is at least one of the said 1st and 2nd molten glass conveying pipes 1 installed plate glass manufacturing device. A molten glass stirring method using the molten glass stirring device according to claim 1. The plate glass manufacturing method using the plate glass manufacturing apparatus of Claim 3 or 4.

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