JP2014062009A - Glass plate production apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a float glass molding method which allows avoiding of degradation of glass plate quality which is attributed to the adhesion of dross.SOLUTION: In a glass plate production apparatus 1 which is configured such that molten glass is successively supplied from upstream to the surface of molten tin S reserved in a float bath 2 to mold a glass ribbon G, and at the same time the glass ribbon G after being molded is withdrawn from the float bath 2 by separating it from the surface of the molten tin S near a downstream end wall 2a in the float bath 2, a bottom area 2bL in a downstream end region L of the float bath 2 has a protuberance part 3 protruding with respect to the bottom part 2bH in an upstream side region H overlapping the upstream side of the downstream end region L. The protuberance part 3 is configured to have a substantially symmetrical shape in width direction perpendicular to the flow direction of the glass ribbon G, and to have a top part 3a at its center, which is positioned lower than the surface of the molten tin S. This configuration prevents the dross from staying at a take off position TO in which the glass ribbon G is separated from the surface of the molten tin S.

Description

  The present invention relates to a glass plate manufacturing apparatus, and more particularly to an apparatus for manufacturing a glass plate by a float process.

  As is well known, a float method is known as one of methods for forming glass. In this float method, a metal having a density higher than that of glass is melted and stored in a float bath, and then molten glass is continuously supplied to the surface of the molten metal from the upstream side to form a glass ribbon and to remove the float bath from the float bath. The glass ribbon after forming is separated from the surface of the molten metal and is drawn out using a roller provided on the downstream side.

  By the way, as a molten metal stored in the float bath, it is customary to use molten tin, but a part of this molten tin reacts with oxygen and sulfur in the float bath and is called dross. It becomes an impurity and floats on the molten tin. Therefore, when the glass ribbon is pulled out, if the dross stays at a position where the glass ribbon is separated from the surface of the molten tin (hereinafter referred to as a take-off position), the glass ribbon after molding is attached to the dross. Withdrawn from the float bath.

  As a result, the glass ribbon to which the dross adheres has a defect such as a defect, and due to this, the quality of the glass plate (glass plate product) manufactured from the glass ribbon is greatly reduced. There was a problem. Therefore, in order to solve such a problem, Patent Document 1 discloses an apparatus aimed at preventing dross from staying at the take-off position.

  In detail, in this document, a weir extending in the width direction perpendicular to the longitudinal direction of the float bath (flow direction of the glass ribbon) is arranged at a position slightly spaced upstream from the downstream end wall of the float bath. In addition, a flow path of molten metal that extends from between the downstream end wall and the weir to the outside of the float bath and is connected to the upstream side of the weir is provided on the side of the float bath. A glass plate manufacturing apparatus provided with a linear induction motor is disclosed.

JP 2000-128552 A

  According to such a configuration, the molten metal that has been pulled by the flow of the glass ribbon and has passed through the weir to the downstream side is formed between the downstream end wall and the weir in the width direction by the induction action of the linear induction motor. After flowing in the direction, it is assumed that it passes through the above-mentioned flow path and returns to the float bath on the upstream side of the weir. Therefore, it can be expected that the dross flowing between the downstream end wall and the weir is guided to the flow path along this flow, and dross retention at the take-off position is prevented.

  However, due to the following circumstances, even with the apparatus disclosed in Patent Document 1, it has still been difficult to sufficiently prevent dross from staying at the take-off position.

  That is, according to the apparatus disclosed in this document, as shown in FIG. 8, in the region A in the vicinity of the flow path 101 (inlet 101a) between the downstream end wall 100a of the float bath 100 and the weir 102. By the induction action of the linear induction motor (not shown), it is possible to form a flow of the molten metal M toward the side as indicated by the white arrow in the figure. However, normally, the float bath 100 has a large size not only in the longitudinal direction but also in the width direction, so that in the region B near the center in the width direction, the induction action by the linear induction motor is performed. There was a drawback that it was not possible to get enough.

  For this reason, in the region B near the center, the molten metal M does not flow sideways in the width direction, but stays in the vicinity of the take-off position TO, and the dross D floating on the molten tin S is also Similarly, it stays in the vicinity of the take-off position TO. Therefore, in reality, it is still difficult to prevent the dross D from adhering to the glass ribbon G, and thus the deterioration of the quality of the glass plate (glass plate product) due to this.

  The present invention made in view of the above circumstances avoids the deterioration of the quality of the glass plate due to the adhesion of dross by preventing the dross from staying at the take-off position where the glass ribbon is separated from the surface of the molten metal. Technical issue.

  Invented in order to solve the above-mentioned problems, the present invention provides a glass ribbon after molding while continuously supplying molten glass from the upstream side to the surface of the molten metal stored in the float bath to form the glass ribbon. In the glass plate manufacturing apparatus configured to be drawn from the float bath at a position near the downstream end wall in the float bath, the bottom portion in the downstream end region of the float bath corresponds to the downstream end region. The raised portion is raised with respect to the bottom of the upstream region connected to the upstream side, and the raised portion has a substantially symmetric shape in the width direction orthogonal to the flow direction of the glass ribbon, and at the center thereof. It is characterized by having a topmost part located below the surface of the molten metal. Here, the term “substantially symmetrical” includes the case where it is completely symmetric.

  According to such a configuration, the depth of the molten metal stored in the downstream end region is placed in a state of being shallow at the center in the width direction and deepened at the side. For this reason, the molten metal that is pulled by the flow of the glass ribbon, reaches the downstream end region from the upstream region, and rides on the raised portion forms a flow from the shallow center to the deep side. . As a result, even when the float bath has a large size in the width direction, it is possible to guide the dross floating on the molten metal to the side in the width direction on this flow. As a result, dross retention at the take-off position is prevented, so that deterioration of the quality of the glass plate due to dross adhesion can be avoided. Further, since the raised portion has a substantially symmetric shape in the width direction, the temperature distribution of the glass ribbon drawn out from the float bath can be suppressed from being asymmetric with respect to the center portion in the width direction, so that the post-process Therefore, it is possible to eliminate as much as possible the possibility of adversely affecting the molding of the glass ribbon.

  Said structure WHEREIN: It is preferable that the said protruding part is formed so that it may become low toward the side from the center in the said width direction.

  In this way, the depth of the molten metal stored in the downstream end region gradually increases from the center toward the side. Thereby, it becomes possible to form more favorably the flow which goes to the side from the center in the width direction of molten metal.

  Said structure WHEREIN: It is preferable that the said protruding part has an inclined plane inclined in the downward direction toward the side from the center in the said width direction.

  In this way, it has been found that the flow from the center to the side in the width direction of the molten metal can be formed more satisfactorily.

  Said structure WHEREIN: It is preferable that the said protruding part is formed so that the both ends in the said width direction may become higher than the bottom part of the said upstream area | region.

  In this way, it has been found that the flow from the center to the side in the width direction of the molten metal can be formed even better.

  Said structure WHEREIN: It is preferable that the said top part is located in the downstream rather than the boundary of the said upstream area | region and the said downstream end area | region.

  If it does in this way, a protruding part will be formed in the shape which has a climbing gradient along the flow direction of a glass ribbon. Therefore, the molten metal riding on the raised portion can weaken the flow in the direction along the flow direction of the glass ribbon by this climbing gradient. Thereby, it becomes easier to form a flow from the center to the side in the width direction of the molten metal.

  Said structure WHEREIN: It is preferable that the depth from the surface of the said molten metal to the said topmost part is 6 mm or more.

  If it does in this way, it will become possible to prevent the fall of the quality of the glass plate manufactured from the said glass ribbon resulting from the contact with a glass ribbon and a protruding part as much as possible.

  Said structure WHEREIN: It is preferable that the length in the said width direction of the said protruding part is 50% or more with respect to the length in the said width direction of the said float bath.

  If it does in this way, the flow which goes to the side from the center in the width direction of a molten metal can be favorably formed in the whole region in the width direction of a float bath.

  Said structure WHEREIN: It is preferable that the said top part is located in the downstream rather than the position where the said glass ribbon separates from the surface of the said molten metal, or it is following the said downstream end wall.

  If it does in this way, it will become possible to prevent as much as possible that a vortex-like flow generate | occur | produces in a molten metal in the downstream of the top part. As a result, the risk of hindering the formation of the flow from the center to the side in the width direction of the molten metal due to the influence of the vortex flow is reduced, so dross stays in the vicinity of the position where the vortex flow occurred. The occurrence of such a situation can be avoided.

  Said structure WHEREIN: It is preferable to provide the flow path of the said molten metal in the side of the said width direction in the said float bath from the said downstream end area | region to the exterior of this float bath, and connected to the upstream. .

  In this way, the dross floating on the molten metal is guided to the side of the float bath along the flow from the center to the side in the width direction of the molten metal, and then flows into the flow path. It will be. Thereby, dross retention at the take-off position is prevented even better.

  As described above, according to the present invention, it is possible to prevent the dross from staying at the take-off position where the glass ribbon is separated from the surface of the molten metal, thereby avoiding the deterioration of the quality of the glass plate due to the adhesion of the dross. It becomes possible to do.

It is a perspective view which shows the glass plate manufacturing apparatus which concerns on 1st embodiment of this invention. It is a plane sectional view showing an operation of the glass plate manufacturing apparatus concerning a first embodiment of the present invention. It is a perspective view which shows the glass plate manufacturing apparatus which concerns on 2nd embodiment of this invention. It is a perspective view which shows the glass plate manufacturing apparatus which concerns on 3rd embodiment of this invention. It is a perspective view which shows the glass plate manufacturing apparatus which concerns on 4th embodiment of this invention. It is a perspective view which shows the glass plate manufacturing apparatus which concerns on 5th embodiment of this invention. It is a perspective view which shows the glass plate manufacturing apparatus which concerns on 6th embodiment of this invention. It is plane sectional drawing which shows the conventional glass plate manufacturing apparatus.

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

  FIG. 1 is a perspective view showing a glass plate manufacturing apparatus according to the first embodiment of the present invention. The glass plate manufacturing apparatus 1 is an apparatus for forming a glass ribbon G by the float process, and continuously supplies molten glass from the upstream side to the surface of the molten tin S (molten metal) stored in the float bath 2. Then, while forming the glass ribbon G, the glass ribbon G after molding is moved to the vicinity of the downstream end wall 2a which is the end of the flow direction X by a roller (not shown) provided on the downstream side outside the float bath 2. At the take-off position TO that is located, the molten tin S is separated from the surface and drawn out from the float bath 2.

  The float bath 2 is lined with a refractory (for example, refractory brick), and the inside thereof is filled with a mixed gas of hydrogen gas and nitrogen gas as an atmospheric gas. Further, the bottom 2bL in the downstream end region L of the float bath 2 has a raised portion 3 that is raised with respect to the bottom 2bH of the upstream region H connected to the upstream side of the downstream end region L (in this embodiment). The entire bottom portion 2bL of the downstream end region L is a raised portion 3). Further, on the side in the width direction orthogonal to the flow direction X of the glass ribbon G, the flow path 4 of the molten tin S that extends outward from the side wall 2 c of the float bath 2 and is connected to the upstream side of the float bath 2. Is provided.

  The raised portion 3 is made of a refractory material, and the whole is submerged under the surface of the molten tin S stored in the float bath 2. Further, it extends from the inner surface of the downstream end wall 2a to the upstream side, is formed in a symmetrical shape with respect to the center in the width direction of the float bath 2, and extends laterally from the topmost portion 3a located at the center of the raised portion 3 Two trapezoidal inclined planes 3b that are inclined downwardly toward each other, and an inclined plane 3c that joins both the inclined planes 3b and has an upward gradient along the flow direction X of the glass ribbon G. Yes. In addition, the topmost part 3a is continued horizontally from the downstream end wall 3a. Furthermore, both end portions 3 d in the width direction of the raised portion 3 (inclined plane 3 b) serving as a joint portion with the side wall 2 c of the float bath 2 are located higher than the bottom portion 2 b H of the upstream region H.

  Here, the length of the raised portion 3 in the flow direction X of the glass ribbon G (longitudinal direction of the float bath 2) is a length that occupies 5 to 50% of the length in the width direction of the float bath 2. Is preferred. Further, in order to prevent the quality of the glass plate manufactured from the glass ribbon G from being deteriorated due to the contact between the raised portion 3 and the glass ribbon G, from the surface of the molten tin S to the topmost portion 3 a of the raised portion 3. The depth of is preferably 6 mm or more.

  The flow path 4 of the molten tin S has an inlet 4a provided on the downstream side and an outlet 4b provided on the upstream side, and a dross that floats on the molten tin S therebetween. A damming member 5 for damming D is arranged. At the end of the damming member 5 on the downstream end wall 2a side, a curved portion 5a whose shape is curved in an R shape is formed, and the tip of the curved portion 5a sinks below the surface of the molten tin S. Yes. Thereby, since the dross D which flowed into the flow path 4 from the inside of the float bath 2 through the inflow port 4a is dammed by the curved portion 5a formed in the damming member 5, only the molten tin S from which the dross D has been removed is obtained. It returns to the float bath 2 through the outlet 4b.

  Hereinafter, an effect | action of said glass plate manufacturing apparatus 1 is demonstrated.

  As shown in FIG. 2, the molten tin S is pulled by the flow of the glass ribbon G in the X direction, reaches the downstream end region L from the upstream region H, and then rides on the raised portion 3. Here, in the width direction of the float bath 2, the height from the bottom portion 2bH of the upstream region H in the raised portion 3 is reduced from the center toward the side, so that it is stored in the downstream end region L. The depth of the molten tin S is placed under a state where it is shallow at the center and deep at the side.

  Therefore, in the molten tin S riding on the raised portion 3, a flow from the shallow center to the deep side is formed over the entire region in the width direction. As a result, even if the float bath 2 has a large size in the width direction, the dross D floating on the molten tin S is placed on this flow, and as shown by the arrow V in the figure, the width direction It becomes possible to guide to the side (side wall 2c side). The raised portion 3 has two inclined planes 3b inclined downward from the top portion 3a to the side, and both end portions 3d in the width direction of the raised portion 3 are more than the bottom portion 2b of the upstream region H. It is also found that the flow from the center to the side of the molten tin S can be more favorably formed by being located at a high place.

  Furthermore, due to the presence of the gradient surface 3c, the molten tin S riding on the raised portion 3 is weakened in the direction along the flow direction X of the glass ribbon G by the gradient surface 3c. Thereby, it becomes easier to form a flow from the center of the molten tin S to the side. Further, the ridge 3 extends from the inner surface of the downstream end wall 2a to the upstream side (the top 3a of the ridge 3 is continuous from the downstream end wall 2a). Since it is possible to prevent the spiral flow of the molten tin S from occurring on the downstream side of 3a, there is a possibility that the formation of the flow from the center to the side of the molten tin S may be hindered by the influence of the spiral flow. Reduced.

  These prevent the dross D from staying at the take-off position TO, so that it is possible to avoid the deterioration of the quality of the glass plate manufactured from the glass ribbon G after forming due to the adhesion of the dross D. Moreover, according to such a device configuration, it is not necessary to install a weir in the float bath 2. For this reason, it is possible to eliminate the fear that the glass ribbon G is damaged due to the contact between the glass ribbon G and the weir.

  In addition, the dross D guided to the side of the float bath 2 flows into the flow path 4 through the inlet 4a, and is then blocked by the curved portion 5a formed in the blocking member 5 and stays there. . Therefore, only the molten tin S from which the dross D has been removed returns to the float bath 2 through the outlet 4b. As a result, the dross D can be prevented from staying in the vicinity of the take-off position TO, and occurrence of a situation in which the dross D continues to circulate in the float bath 2 and the flow path 4 can be avoided. . The dross D staying in the bending portion 5a is scraped out after a predetermined amount has accumulated.

  Hereinafter, the glass plate manufacturing apparatus which concerns on other embodiment of this invention is demonstrated. In addition, since the structure of the glass plate manufacturing apparatus which concerns on the following 2nd-6th embodiment is the structure same as the glass plate manufacturing apparatus which concerns on said 1st embodiment except the shape of a protruding part, these In the drawings for explaining the embodiments, illustrations other than the raised portions are omitted.

  FIG. 3 is a perspective view showing the glass plate manufacturing apparatus 1 according to the second embodiment of the present invention. The glass plate manufacturing apparatus 1 according to the second embodiment is different from the glass plate manufacturing apparatus 1 according to the first embodiment in that the glass plate manufacturing apparatus 1 is located laterally from the top 3a located at the center of the raised portion 3. The inclined plane 3b inclined downward toward the lower side is changed from a trapezoidal shape to a rectangular shape, joined to both the inclined planes 3b, and has an upward gradient along the flow direction X of the glass ribbon G. The gradient surface 3c is divided into two surfaces and protrudes toward the upstream side as it moves from the side in the width direction to the center. The gradient surface 3c is inclined downward in the width direction from the top 3e located in the center toward the side.

  Even with such a configuration, the molten tin S riding on the raised portion 3 forms a flow from the center where the depth of the molten tin S is shallow toward the deep side. Therefore, the same effects as those already described in the description of the glass plate manufacturing apparatus according to the first embodiment can be obtained.

  FIG. 4 is a perspective view showing the glass plate manufacturing apparatus 1 according to the third embodiment of the present invention. The glass plate manufacturing apparatus 1 according to the third embodiment is different from the glass plate manufacturing apparatus 1 according to the first embodiment in that the inclined plane 3b is removed and the raised portion 3 is only the inclined surface 3c. It is the point formed by. In addition, the gradient surface 3c has the same shape as the gradient surface 3c of the glass plate manufacturing apparatus according to the second embodiment.

  Even with such a configuration, the molten tin S riding on the raised portion 3 forms a flow from the center where the depth of the molten tin S is shallow toward the deep side. Therefore, the same effects as those already described in the description of the glass plate manufacturing apparatus according to the first embodiment can be obtained.

  FIG. 5 is a perspective view showing a glass plate manufacturing apparatus 1 according to the fourth embodiment of the present invention. The glass plate manufacturing apparatus 1 according to the fourth embodiment is different from the glass plate manufacturing apparatus 1 according to the first embodiment in that the raised portion 3 is replaced by the inclined plane 3b and the inclined plane 3c. Thus, the curved surface 3f is curved and curved in an arch shape, and the upright surface 3g is located at the upstream end of the raised portion 3 and is continuous with the curved surface 3f.

  FIG. 6 is a perspective view showing a glass plate manufacturing apparatus 1 according to the fifth embodiment of the present invention. The glass plate manufacturing apparatus 1 according to the fifth embodiment is different from the glass plate manufacturing apparatus 1 according to the first embodiment in that the raised portion 3 is replaced with an inclined plane 3b and an inclined plane 3c. This is a point formed by an elliptical curved surface 3h.

  FIG. 7 is a perspective view showing the glass plate manufacturing apparatus 1 according to the sixth embodiment of the present invention. The glass plate manufacturing apparatus 1 according to the sixth embodiment is different from the glass plate manufacturing apparatus 1 according to the first embodiment in that the length of the raised portion 3 in the width direction is shortened. (In this embodiment, a part of the bottom 2bL of the downstream end region L is the raised portion 3). This length in the width direction is 50% of the length in the width direction of the float bath 2, and accordingly, the inclination angle of the inclined plane 3b and the inclined plane 3c is larger than that in the first embodiment. It has become.

  Also by the structure of the glass plate manufacturing apparatus according to the fourth to sixth embodiments, a flow from the center where the depth of the molten tin S is shallow toward the deep side is formed in the molten tin S riding on the raised portion 3. Is done. Therefore, the same effects as those already described in the description of the glass plate manufacturing apparatus according to the first embodiment can be obtained.

  Here, the glass plate manufacturing apparatus which concerns on this invention is not limited to the structure demonstrated in said each embodiment. For example, in each of the above-described embodiments, the raised portion is configured to extend from the inner surface of the downstream end wall of the float bath to the upstream side, but is configured to extend from the vicinity of the inner surface of the downstream end wall to the upstream side. It is good. Such a configuration is preferably employed when the downstream end wall and the take-off position are not close to each other. In this case, even if the raised portion does not extend from the inner surface of the downstream side end wall, it is possible to prevent a swirling flow of molten tin from occurring on the downstream side of the topmost portion of the raised portion. As a result, the risk of hindering the formation of the flow of molten tin from the center to the side due to the spiral flow is reduced, and the occurrence of a situation in which dross stays on the downstream side of the topmost part is avoided. be able to.

  In addition, the shape of the raised portion is not limited to the shape described in each of the above embodiments, and has a symmetric or substantially symmetric shape in the width direction orthogonal to the flow direction of the glass ribbon. As long as it has the topmost part located below the surface of the molten tin at the center, it may be formed in another shape, and the same effects as those of the above embodiments can be obtained. However, the temperature distribution of the glass ribbon drawn out from the float bath becomes asymmetric with respect to the central portion, and in order to avoid adversely affecting the forming of the glass ribbon in the subsequent process, it is preferable to have a symmetric shape.

  Furthermore, the width direction length of the raised portion is the same as the width direction length of the float bath in the first to fifth embodiments, and in the sixth embodiment, the width direction length of the float bath. It is 50% of. However, it is not limited to these, and it is only necessary to have a length of 50% or more with respect to the length in the width direction of the float bath. That is, as the length in the width direction of the raised portion, one having a length of 50% to 100% with respect to the length in the width direction of the float bath can be adopted. The same effect as the form can be obtained.

  In addition, in each of the above embodiments, both end portions in the width direction of the raised portion are configured to be higher than the bottom portion of the upstream region, but both end portions and the bottom portion of the upstream region are the same height. The both ends may be positioned below the bottom of the upstream region. Moreover, the flow path of the molten tin provided in the side of the float bath does not necessarily need to be provided.

DESCRIPTION OF SYMBOLS 1 Glass plate manufacturing apparatus 2 Float bath 2a Downstream end wall 2bH Upstream area bottom 2bL Downstream end area bottom 2c Side wall 3 Raised part 3a Topmost part 3b Inclined plane 3c Gradient surface 3d End part 3e Top part 3f Curved surface 3g Upright surface 3h Elliptical surface 4 Molten tin flow path 4a Inlet 4b Outlet 5 Damping member 5a Curved portion H Upstream region L Downstream end region G Glass ribbon X Glass ribbon flow direction S Molten tin TO Take-off position D Doros V Molten tin Flow of

Claims (9)

While the molten glass is continuously supplied from the upstream side to the surface of the molten metal stored in the float bath to form a glass ribbon, the glass ribbon after molding is formed near the downstream end wall of the float bath. In a glass plate manufacturing apparatus configured to be separated from the surface and pulled out from the float bath,
The bottom in the downstream end region of the float bath has a raised portion raised relative to the bottom of the upstream region connected to the upstream side of the downstream end region;
The raised portion has a substantially symmetric shape in the width direction orthogonal to the flow direction of the glass ribbon, and has a topmost portion located below the surface of the molten metal at the center thereof. Board manufacturing equipment.   The said protruding part is formed so that it may become low toward the side from the center in the said width direction, The glass plate manufacturing apparatus of Claim 1 characterized by the above-mentioned.   3. The glass plate manufacturing apparatus according to claim 1, wherein the raised portion has an inclined plane inclined downward from the center toward the side in the width direction.   The said protruding part is formed so that the both ends in the said width direction may become higher than the bottom part of the said upstream area | region, The glass plate manufacturing apparatus in any one of Claims 1-3 characterized by the above-mentioned.   The said top part is located in the downstream rather than the boundary of the said upstream area | region and the said downstream end area | region, The glass plate manufacturing apparatus in any one of Claims 1-4 characterized by the above-mentioned.   The depth from the surface of the said molten metal to the said top part is 6 mm or more, The glass plate manufacturing apparatus of Claims 1-5 characterized by the above-mentioned.   The length in the said width direction of the said protruding part is 50% or more with respect to the length in the said width direction of the said float bath, The glass plate manufacturing apparatus in any one of Claims 1-6 characterized by the above-mentioned. .   The topmost part is located downstream from the position where the glass ribbon is separated from the surface of the molten metal, or is continuous with the downstream end wall. The glass plate manufacturing apparatus of crab.   The flow path of the molten metal that extends from the downstream end region to the outside of the float bath and is connected to the upstream side is provided on a side of the float bath in the width direction. The glass plate manufacturing apparatus in any one of -8.

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