KR20210007258A - System for manufacturing glass plate - Google Patents

Abstract

An embodiment according to an aspect of the present invention provides a system for manufacturing a glass plate comprising: a float bath forming a glass ribbon by floating molten glass on a molten metal liquid surface; a slow cooling furnace slowly cooling the molded glass ribbon to form plate glass; a plurality of transfer rollers drawing out the glass ribbon from the float bath and transferring the same on the slow cooling furnace; and a control part controlling the rotation speed of a driving roller among the plurality of transfer rollers when the deviation between the transfer speed of the glass ribbon and the rotational linear speed of some of the plurality of transfer rollers exceeds a reference value. The present invention can secure a high glass product manufacturing yield.

Description

Plate glass manufacturing system {SYSTEM FOR MANUFACTURING GLASS PLATE}

The present invention relates to a plate glass manufacturing system.

As one of the methods of manufacturing plate glass, a float method is used, and the float method has the advantage of efficiently manufacturing a large area plate glass.

The float method includes a molding process in which molten glass is continuously formed into a glass ribbon in a float bath in which molten metal is stored, and a slow cooling process in which the formed glass ribbon is slowly cooled in a slow cooling furnace.

On the other hand, when the speed of the glass ribbon drawn out from the float bath through the molding process and the speed between the transfer rollers that transfer the glass ribbon during the slow cooling process are inconsistent, a tensile force is generated between the transfer roller and the lower surface of the glass ribbon. If the tensile force is excessive, it causes a fine crack on the lower surface of the glass ribbon.

Such cracks may have a problem in that the glass product is easily damaged during post-processing of glass products such as cutting, processing, and polishing, or during the manufacturing process of a display unit using the glass product.

The present invention has been conceived to solve the above-described problem, and provides a plate glass manufacturing system for preventing a large difference in speed between the drawing speed of the glass ribbon drawn out from the float bath and the transfer roller for transferring the glass ribbon during the slow cooling process. It aims to do.

However, the problem to be solved by the present invention is not limited to the above-mentioned problems, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

An embodiment according to an aspect of the present invention, a float bath for forming a glass ribbon by floating molten glass on the liquid surface of the molten metal; A slow cooling furnace for slowly cooling the molded glass ribbon to form a plate glass; A plurality of transfer rollers for drawing the glass ribbon from the float bath and transferring it on the slow cooling furnace; And when the deviation of the transfer speed of the glass ribbon and the rotational linear speed of some transfer rollers of the plurality of transfer rollers exceeds a reference value, the It provides a plate glass manufacturing system comprising a control unit for controlling the rotational speed of the driving roller among a plurality of transfer rollers.

In this embodiment, a plurality of imaging units for imaging the glass ribbon at a predetermined distance along the transport direction of the glass ribbon; And a transfer speed calculating unit configured to calculate a transfer speed of the glass ribbon based on the pattern of the glass ribbon captured through the plurality of imaging units.

In this embodiment, a top roll is provided inside the float bath to apply tension to the glass ribbon in a width direction by contacting an upper portion outside the width direction of the glass ribbon, and the plurality of imaging units are provided by the top roll. A pattern formed on the outer upper part of the glass ribbon in the width direction may be captured.

In the present embodiment, at least some of the plurality of imaging units may be located in an area in which first to twentieth conveying rollers are disposed in an order of adjacent to the float bath side among the plurality of conveying rollers.

In this embodiment, at least a portion of the plurality of imaging units is a region in which lift-out rollers are arranged so as to gradually increase in position along the conveying direction of the glass ribbon on the outlet side of the float bath among the plurality of conveying rollers. Located within a pane manufacturing system.

In this embodiment, the control unit compares the feed speed of the glass ribbon in the region where the lift-out roller is disposed and the rotational linear speed of at least one lift-out roller among the plurality of lift-out rollers based on a comparison value. It is possible to control the rotation speed of the driving roller among a plurality of conveying rollers.

According to an embodiment of the present invention, a large difference in speed between the drawing speed of the glass ribbon drawn out from the float bath and the transfer roller for transferring the glass ribbon to the slow cooling furnace is prevented, thereby preventing the formation of cracks on the surface of the glass ribbon. It can be suppressed, and accordingly, it is possible to secure a high glass product manufacturing yield.

1 is a cross-sectional view showing a plate glass manufacturing system according to an embodiment of the present invention.
2 is a view schematically showing a partial section of the plate glass manufacturing system according to an embodiment of the present invention.
3 is an image obtained by taking an image from either end side of both ends of the glass ribbon G in an actual process.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become apparent with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims. Meanwhile, terms used in the present specification are for explaining embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprises" and/or "comprising" refers to the presence of one or more other components, steps, actions and/or elements, and/or elements, steps, actions and/or elements mentioned. Or does not preclude additions. Terms such as first and second may be used to describe various components, but the components should not be limited by terms. The terms are only used for the purpose of distinguishing one component from another component.

1 is a cross-sectional view illustrating a system for manufacturing a plate glass according to an exemplary embodiment of the present invention, and FIG. 2 is a view schematically illustrating a partial section of a system for manufacturing a plate glass according to an exemplary embodiment of the present invention.

The plate glass manufacturing system 100 includes a float bath 110, a slow cooling furnace 120, a chamber 130 disposed between the float bath 110 and the slow cooling furnace 120, and the chamber 130 and the slow cooling furnace 120. ) It may include a plurality of transfer rollers 140 for transferring the glass ribbon (G).

The molten glass is supplied onto the molten metal M in the float bath 110 to form a plate-shaped glass ribbon G. The glass ribbon G gradually hardens while floating on the molten metal M and flowing. The glass ribbon G is separated from the molten metal M in the downstream region of the float bath 40 and is transferred toward the slow cooling furnace 120. In the slow cooling furnace 120, the molded glass ribbon G is slowly cooled to be manufactured into plate glass.

The glass ribbon G molded to a desired width or thickness on the liquid level of the molten metal M in the float bath 110 is separated from the liquid level by the pulling force of the plurality of transfer rollers 140 and is drawn out. Then, the glass ribbon (G) is carried into the chamber 130 from the outlet (110a) of the float bath 110, and is transferred through the lift-out rollers (141a to 141c) of the plurality of transfer rollers 140. Subsequently, the glass ribbon G is carried in the slow cooling furnace 120 and slowly cooled while being transferred through the transfer rollers 142, 143, .... Thereafter, the glass ribbon G is taken out of the slow cooling furnace 120 and cooled to near room temperature, and then cut into a predetermined size to be manufactured into a final product of plate glass.

The glass ribbon G is formed by pouring and dissolving plural kinds of raw materials corresponding to the final product of plate glass into a melting tank to produce a molten glass, and continuously supplying the molten glass into the float bath 110 to form. Before supplying the molten glass into the float bath 110, it is preferable that air bubbles contained in the molten glass are defoamed and clarified.

The float bath 110 includes a spout lip 111, a twill 112, a bath 113, a ceiling wall 114, a casing 115, an upper roll 116, a heater 117, and a gas supply pipe 118. Can include.

The spout lip 111 supplies the bath 113 with molten glass of a flow rate according to the interval with the twill 20.

The bath 113 accommodates the molten metal M from which the glass ribbon G floats. The molten metal (M) may be, for example, molten tin or molten tin alloy, but is not limited thereto. The liquid level of the molten metal M has, as shown in FIG. 2, a covered portion covered with the glass ribbon G, and an exposed portion that is not covered with the glass ribbon G. The exposed portion is formed on both left and right sides of the covering portion. The bath 113 may be made of, for example, a brick.

The ceiling wall 114 is disposed above the bath 113 as shown in FIG. 1 to cover the upper space 113a of the bath 113. In the upper space 113a of the bath 113, a reducing gas or an inert gas may be supplied from the through hole 114a of the ceiling wall 114 in order to prevent oxidation of the molten metal M. As the reducing gas, a mixed gas of nitrogen gas and hydrogen gas may be used, for example.

The casing 115 forms a space between the ceiling wall 114 (hereinafter, the inner space of the casing 115). After the reducing gas or inert gas is supplied to the inner space of the casing 115 through the gas supply pipe 118, it is supplied to the upper space 113a of the bath 113 through the through hole 114a of the ceiling wall 114 Can be. The gas supply pipe 118 may be provided on the casing 115 to supply a reducing gas or an inert gas to the inner space of the casing 115.

As shown in FIG. 2, the upper roll 116 can apply tension to the glass ribbon G in the width direction by supporting both ends in the width direction over a predetermined section of the glass ribbon G. Thereby, shrinkage in the width direction of the glass ribbon G is restricted, and it can shape|mold into the thin glass ribbon G.

As shown in FIG. 1, the heater 117 is inserted into the through hole 114a of the ceiling wall 114, protrudes downward from the ceiling wall 114, and can heat the glass ribbon G. .

The glass ribbon molded in the float bath 110 may be carried into the slow cooling furnace 120. The slow cooling furnace 120 generally uses air as a slow cooling gas, and since the outlet on the downstream side is open to the outside, the inside of the slow cooling furnace 120 is basically placed in an atmospheric atmosphere. The inside of the slow cooling furnace 120 may communicate with the inside of the float bath 110 through the inside of the chamber 130.

The chamber 130 may include a hood 131 installed above the glass ribbon G, and a dross box 132 installed below the glass ribbon G. It is preferable that the chamber 130 has an insulating structure. By suppressing heat dissipation from the chamber 130, thereby stabilizing the temperature distribution of the glass ribbon G, it is possible to suppress the warpage of the product.

A plurality of lift-out rollers 141a, 141b and 141c, a contact member 133, and a drape 134 among the plurality of transfer rollers 140 may be disposed in the chamber 130.

Each of the lift-out rollers 141a, 141b, and 141c is rotationally driven by a driving unit such as a motor, and the glass ribbon G can be obliquely conveyed upward by the driving force. A contact member 133 may be installed under the lift-out rollers 141a, 141b, and 141c.

The contact member 133 may be formed of carbon or the like. The contact members 133 may be in sliding contact with the outer peripheral surfaces of the corresponding lift-out rollers 141a, 141b and 141c, respectively.

The drape 134 is provided above the glass ribbon G, and is a member which partitions the space above the glass ribbon G. The drape 134 restricts the mixing of air from the slow cooling furnace 120, thereby suppressing an increase in the oxygen concentration in the chamber 130.

A drape or an inert gas supply unit 150 may be provided on the side of the outlet 110a of the float bath 110 to limit the movement of airflow between the chamber 130 and the float bath 110 by being installed above the glass ribbon. The inert gas supplied through the inert gas supply unit 150 is nitrogen (N ₂ ), oxygen (O ₂ ), helium (He), neon (Ne), argon (Ar), krypton (Cr), and xenon (Xe). It may be at least one gas selected from the inert gas group consisting of, and preferably, nitrogen gas.

Among the plurality of transfer rollers 140, the remaining transfer rollers 142 and 143 excluding the lift transfer rollers 141a, 141b and 141c may be provided in the slow cooling furnace 120.

In the plate glass manufacturing system 100 according to an embodiment of the present invention, when the difference between the feed speed of the glass ribbon G and the rotational linear speed of some of the plurality of feed rollers 140 exceeds the reference value, the plurality of feed rollers ( 140) may include a control unit (not shown) for controlling the rotational speed of the driving roller. The control unit may be implemented in various forms such as a circuit board for controlling the rotational speed of a driving roller, an integrated circuit chip, a series of computer programs mounted on hardware, firmware, software, and the like.

If the difference between the feed speed of the glass ribbon G and the rotational linear speed of the feed roller 140 is large, a tensile force acts between the glass ribbon G and the feed roller 140, causing cracks in the glass ribbon G. have. Therefore, in the embodiment of the present invention, the control unit controls the rotational speed of the driving roller when the difference between the feed rate of the glass ribbon G and the rotational linear speed of some feed rollers exceeds the reference value to control the feed rate of the glass ribbon G And the rotational linear speed of the conveying roller can be made substantially the same.

Here, the'reference value' is the cumulative management of the degree of crack formation of the glass ribbon G according to the difference between the feed speed of the glass ribbon G and the rotational linear speed of some feed rollers, so that cracks in the glass ribbon G are not formed. It can be set to the extent that it does not. For example, the reference value of the difference between the feed speed of the glass ribbon G and the rotational linear speed of some feed rollers may be set to a level of 1% compared to the feed speed of the glass ribbon G.

The plate glass manufacturing system 100 according to the embodiment of the present invention includes a plurality of imaging units 160a and 160b and a plurality of imaging units for imaging the glass ribbon G at a predetermined distance along the transport direction of the glass ribbon G. It may further include a feed rate calculation unit (not shown) for calculating the feed rate of the glass ribbon (G) based on the pattern of the glass ribbon (G) captured through (160a, 160b).

At least one of the plurality of imaging units 160a and 160b may be disposed adjacent to the outlet 110b in the float bath 110, and the other at least one 160b includes the chamber 130 and the slow cooling furnace ( 120) may be disposed on at least one of.

It is preferable that the position of the plurality of imaging units 160a and 160b arranged on the basis of the width direction of the glass ribbon G is a position capable of easily capturing a pattern uniquely formed on the glass ribbon G. The upper roll 116 is used as a molding means for limiting the reduction in the width direction of the glass ribbon G inside the float bath 110, and this upper roll 116 is in the width direction of the glass ribbon G in a predetermined section. It supports both ends. At this time, finely curved patterns may be formed on both ends of the glass ribbon G that is in contact with the upper roll 116. 3 is an image obtained by taking an image from either end of the both ends of the glass ribbon G in an actual process, and it can be seen that a curved pattern is formed. Accordingly, it is preferable that the plurality of imaging units 160a and 160b are disposed at a position capable of imaging a pattern formed on at least one end side of both ends of the glass ribbon G in the width direction by the upper roll 116 Do.

The feed rate calculation unit may be implemented in various forms such as a circuit board, an integrated circuit chip, a series of computer programs mounted on hardware, firmware, software, and the like, according to embodiments. When it is confirmed that the same pattern exists between the images captured by each of the plurality of imaging units 160a and 160b, the feed rate calculation unit captures the time difference at which the corresponding images are captured and each of the plurality of imaging units 160a and 160b. The feed rate of the glass ribbon G can be calculated based on the difference between the positions.

Among the plurality of imaging units 160a and 160b, the imaging unit 160b disposed in at least one of the chamber 130 and the slow cooling furnace 120 is adjacent to the float bath 110 side of the plurality of transfer rollers 140 It is preferable that the first to twentieth conveying rollers 141a, 141b, 141c, 142, 143, ... are located in an area in which the first to 20th transfer rollers are arranged.

The glass ribbon (G) is withdrawn from the float bath 110 and transferred onto the chamber 130 and the slow cooling furnace 120, and is upward from the liquid level of the molten metal (M) at the outlet 110a of the float bath 110. Since it is withdrawn while spaced apart, the transfer rollers (141a, 141b, 141c, 142, 143, ...) in the section adjacent to the outlet (110a) side of the float bath (110) is unstable and the glass ribbon ( This is because the probability of crack formation on G) is relatively high compared to other sections.

Among the plurality of imaging units 160a and 160b, the imaging unit 160b disposed in at least one of the chamber 130 and the slow cooling furnace 120 is, in particular, of the float bath 110 among the plurality of transfer rollers 140. It is preferable that the lift-out rollers 141a, 141b, and 141c are arranged so as to gradually increase their position along the conveying direction of the glass ribbon G on the outlet 110a side. More preferably, the imaging unit 160b may be disposed to capture an image above the area where the first lift-out roller 141a is located.

On the other hand, the plate glass manufacturing system 100 according to the embodiment of the present invention includes a detection unit 170 capable of detecting the rotational linear speed of the transfer roller 140 to be compared with the transfer speed of the glass ribbon (G). can do.

The sensing unit 170 may be provided with a sensor for detecting the rotation rpm of the transfer roller, may be provided for each transfer roller, may be provided only to some of the transfer rollers 140 of the plurality. Preferably, among the plurality of imaging units 160a and 160b, the sensing unit 170 is provided on the transfer roller at a position corresponding to the imaging unit 160b disposed in at least one of the chamber 130 and the slow cooling furnace 120 It may be provided, and in this embodiment, it is provided on the first lift-out roller 141a. The sensing unit 170 may calculate the rotational linear speed of the transfer roller based on the rotation rpm of the transfer roller and the radius information of the transfer roller.

When the difference between the feed speed of the glass ribbon (G) and the rotational linear speed of some of the plurality of feed rollers exceeds the reference value, the driving roller that controls the rotation speed is lift-out rollers (141a, 141b, 141c). I can.

Since the imaging units 160a and 160b are used inside at least one of the float bath 110 and the chamber 130, they are used in a high temperature environment of about 600 to 900°C. Accordingly, it is preferable that the imaging units 160a and 160b include separate cooling means to enable imaging in a high temperature environment.

According to an embodiment of the present invention, a large difference in speed between the drawing speed of the glass ribbon drawn out from the float bath and the transfer roller for transferring the glass ribbon to the slow cooling furnace is prevented, thereby preventing the formation of cracks on the surface of the glass ribbon. It can be suppressed, and accordingly, it is possible to secure a high glass product manufacturing yield.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the scope of the appended claims will include such modifications or variations as long as they fall within the gist of the present invention.

100: plate glass manufacturing system 110: spout lip
112: Twill 113: Bath
114: ceiling wall 115: casing
116: upper roll 117: heater
118: gas supply pipe 120: slow cooling furnace
130: chamber 131: hood
132: dross box 133: contact member
140: feed rollers 141a, 141b, 141c: lift out rollers
142, 143: transfer rollers excluding lift-out rollers
160a, 160b: imaging unit 170: sensing unit

Claims (6)

A float bath for floating molten glass on a molten metal liquid surface to form a glass ribbon;
A slow cooling furnace for slowly cooling the molded glass ribbon to form a plate glass;
A plurality of transfer rollers for drawing the glass ribbon from the float bath and transferring it on the slow cooling furnace; And
If the difference between the feed speed of the glass ribbon and the rotational linear speed of some of the plurality of feed rollers exceeds a reference value, a control unit for controlling a rotation speed of a driving roller among the plurality of feed rollers. The method of claim 1,
A plurality of imaging units for imaging the glass ribbon at a predetermined distance along the transport direction of the glass ribbon; And
Plate glass manufacturing system comprising a; a feed rate calculation unit for calculating a feed rate of the glass ribbon based on the pattern of the glass ribbon imaged through the plurality of imaging units. The method of claim 2,
An upper roll is provided inside the float bath to support both ends of the glass ribbon in the width direction to apply tension in the width direction to the glass ribbon,
The plurality of imaging units capture patterns formed on at least one end-side upper portion of both ends in the width direction of the glass ribbon by the upper roll. The method of claim 2,
At least a portion of the plurality of imaging units is located in an area in which first to twentieth conveying rollers are arranged in an order adjacent to the float bath side of the plurality of conveying rollers. The method of claim 1,
At least some of the plurality of imaging units are located in an area in which a lift-out roller arranged to gradually increase in position along the conveying direction of the glass ribbon on the outlet side of the float bath among the plurality of conveying rollers system. The method of claim 5,
The control unit is driven among the plurality of conveying rollers based on a difference between the conveying speed of the glass ribbon in the region where the lift-out roller is disposed and the rotational linear speed of at least one of the plurality of lift-out rollers. A plate glass manufacturing system that controls the rotational speed of the rollers.

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