JPWO2019130901A1 - How to manufacture feeders and glass articles - Google Patents

Abstract

A feeder 3 for circulating the molten glass Gm inside, an electric heating element 5 for heating the molten glass Gm, a first space S1 in which the molten glass Gm is arranged, and a second space S2 in which the electric heating element 5 is arranged. It is provided with a partition plate 6 that completely partitions the space. The molten glass Gm is heated by the heat from the partition plate 6 heated by the electric heating element 5.

Description

The present invention relates to a feeder for circulating molten glass inside and a method for manufacturing a glass article using the feeder.

For example, when supplying molten glass to a bushing for molding glass fibers or a molded body for molding flat glass, the molten glass circulating inside the feeder is kept warm to prevent an excessive temperature drop. There is a need. As a method for that purpose, a method of arranging a burner that mixes and burns fuel such as natural gas and air (oxygen) in the internal space of the feeder and heating the molten glass by the heat has been widely adopted. (See Patent Document 1).

By the way, in the case of the method of heating using a burner, (1) the environmentally hazardous substance contained in the molten glass, for example, boron oxide (B ₂ O ₃ ) is easily volatilized by the heat of the burner, and (2) the combustion of the burner. The oxidation-reduction atmosphere in the internal space tends to fluctuate depending on the state, and riboyl bubbles are likely to be generated in the molten glass. (3) When dust contained in the combustion exhaust gas is mixed in the molten glass, the glass produced from the molten glass There is a risk of problems such as causing defects (foreign matter) in the article.

Therefore, for example, Patent Document 2 discloses a method in which an electric heating element is arranged in place of a burner in the internal space of the feeder, and the molten glass is heated by the heat. Specifically, the document describes directly to the molten glass as part of the heat transfer path from the electric heating element to the surface of the molten glass in order to homogenize the temperature distribution of the molten glass flowing inside the feeder. It is disclosed that a limiting portion for limiting heat transfer is provided. As a result, the direct heat transfer from the electric heating element to the molten glass was restricted, the heat transfer path bypassing the limiting portion to the surface of the molten glass, and the heat from the electric heating element heated the limiting portion. Later, the heat from the electric heating element is transferred to the molten glass by two heat transfer paths leading to the surface of the molten glass as heat from the limiting portion.

Special Table 2010-513183 International Publication No. 2014/185132

In the configuration disclosed in Patent Document 2, the space where the electric heating element is arranged and the space where the molten glass is arranged are directly communicated with each other in the heat transfer path that bypasses the restriction portion and reaches the surface of the molten glass. .. Therefore, when a part of the electric heating element is defective due to a defect or the like, the defective portion may be mixed into the molten glass via the communicating portion of both spaces. In particular, when a part of the electric heating element is defective due to sparking, the defective portion is easily scattered around due to the impact at the time of sparking and mixed in the molten glass. If such a defective portion is mixed in the molten glass, it causes a defect in the manufactured glass article.

An object of the present invention is to surely prevent a situation in which a glass article is defective.

In the present invention, which was devised to solve the above problems, an electric heating element that heats the molten glass, a first space in which the molten glass is arranged, and an electric heating element are arranged in a feeder that distributes the molten glass inside. It is characterized in that it is provided with a partition member that completely partitions the second space. According to such a configuration, the first space in which the molten glass is arranged and the second space in which the electric heating element is arranged are completely partitioned by the partition member, so that they are independent spaces. Therefore, even if a part of the electric heating element is defective due to sparks or the like, the defective portion surely stays in the second space and does not mix in the molten glass in the first space. Here, after the partition member is heated by the heat from the electric heating element and the heat from the second space heated by the electric heating element, the molten glass is heated by the heat from the partition member. That is, the molten glass is indirectly heated via the partition member.

In the above configuration, it is preferable that at least a part of the electric heating element is arranged directly above the molten glass. In this way, the heat of the electric heating element is easily transferred to the molten glass, so that the heating efficiency of the molten glass is improved.

In the above configuration, it is preferable that the electric heating element is arranged sideways in the second space. By doing so, the volume of the second space accommodating the electric heating element can be reduced, so that the heat loss in the second space is reduced. Therefore, the molten glass can be efficiently heated while suppressing the electric energy input to the electric heating element.

In the above configuration, it is preferable that the electric heating element extends along the width direction orthogonal to the flow direction of the molten glass. In this way, since the end of the electric heating element faces the side space of the feeder, the electric heating element can be replaced by using the side space of the feeder. The temperature of the side space of the feeder is lower than that of the space above it, and there is often room for space. Therefore, the replacement work of the electric heating element becomes easier than the case where the replacement work of the electric heating element is performed using the space above the feeder. When the electric heating element extends along the flow direction or the vertical direction of the molten glass, it is often necessary to replace the electric heating element by using the space above the feeder.

In the above configuration, it is preferable that the second space is continuous so as to cover the entire width of the molten glass in the width direction orthogonal to the flow direction of the molten glass. The second space is a heating space that is heated by the heat of the electric heating element. Therefore, if the second space is continuous so as to cover the entire width of the molten glass, the entire width of the molten glass can be easily heated uniformly by the heat from the partition member provided at the position corresponding to the second space. As a result, the temperature distribution of the molten glass circulating inside the feeder is made uniform, so that a high-quality glass article can be produced from the molten glass.

In this case, it is preferable that the electric heating elements are arranged directly above both ends in the width direction of the molten glass and directly above the central portion in the width direction of the molten glass. In this way, the partition member is heated more quickly and uniformly in the width direction, so that the heat from the partition member makes it easier to heat the entire width of the molten glass more uniformly.

In the above configuration, the second space may be divided into a plurality of parts in the flow direction of the molten glass. In this way, the temperature distribution in the flow direction of the molten glass can be controlled in a plurality of zones, so that the molten state of the molten glass can be precisely controlled.

In the above configuration, it is preferable that the partition member is made of alumina-based electroformed brick. Alumina electroformed brick is suitable as a partition member because it has good thermal conductivity and is not easily deteriorated by heat.

In the above configuration, it is preferable that the bottom of the feeder is provided with a bushing for forming molten glass into glass fibers.

The present invention, which was devised to solve the above problems, is a method for manufacturing a glass article including a step of distributing molten glass inside a feeder, in which the feeder is provided with an electric heating element for heating the molten glass and is melted. It is characterized by providing a partition member that completely separates the first space in which the glass is arranged and the second space in which the electric heating element is arranged. According to such a configuration, it is possible to obtain the same effect as the corresponding configuration described above.

According to the present invention, it is possible to reliably prevent a situation in which a glass article is defective due to a defect in the heating element inside the feeder.

It is a longitudinal side view which shows the manufacturing apparatus of the glass article provided with the feeder which concerns on 1st Embodiment of this invention. It is sectional drawing of AA in FIG. FIG. 2 is a sectional view taken along line BB in FIG. It is a top view for demonstrating the support form of an electric heating element. FIG. 4C is a sectional view taken along the line CC of FIG. 4A. It is a vertical sectional front view which shows the feeder which concerns on 2nd Embodiment of this invention. It is a vertical sectional front view which shows the feeder which concerns on 3rd Embodiment of this invention. It is a longitudinal front view which shows the feeder which concerns on 4th Embodiment of this invention. It is a longitudinal front view which shows the feeder which concerns on 5th Embodiment of this invention. It is a longitudinal front view which shows the feeder which concerns on 6th Embodiment of this invention. It is a longitudinal front view which shows the feeder which concerns on 7th Embodiment of this invention. It is a longitudinal front view which shows the feeder which concerns on 8th Embodiment of this invention. It is a vertical sectional front view which shows the feeder which concerns on 9th Embodiment of this invention. It is a vertical sectional front view which shows the feeder which concerns on tenth embodiment of this invention.

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

(First Embodiment)
As shown in FIG. 1, the method for manufacturing a glass article according to the first embodiment is to manufacture a glass fiber Gf as a glass article by using the glass article manufacturing apparatus 1. The glass article manufacturing apparatus 1 includes a melting furnace 2 that melts the glass raw material Gr to form the molten glass Gm, and a feeder 3 that is connected to the downstream side of the melting furnace 2 and distributes the molten glass Gm inside. There is. The wall portion that partitions the melting space of the melting furnace 2 and the distribution space of the feeder 3 is formed of a refractory material such as brick.

At the upstream end of the melting furnace 2, a charging port 2a for charging the glass raw material Gr, which is a mixture of silica sand, limestone, soda ash, cullet, etc., into the furnace is provided. A raw material supply means (not shown) such as a screw feeder is arranged at the input port 2a.

The melting furnace 2 is further provided with heating means (not shown). As the heating means, for example, an electric heating means such as a gas burner or an electric heater arranged on the upper part of the molten glass Gm or an electrode immersed in the molten glass Gm can be used. The molten glass Gm is continuously formed by melting the glass raw material Gr charged from the charging port 2a by heating by the heating means. The molten glass Gm flows into the feeder 3 from the downstream end of the melting furnace 2. The melting furnace 2 may melt the glass raw material Gr only by gas combustion or electric heating, or may melt the glass raw material Gr by using gas combustion and electric heating in combination.

A plurality of bushings 4 made of platinum or a platinum alloy are provided on the bottom portion 3a of the feeder 3 at intervals in the flow direction X of the molten glass Gm. Each bushing 4 is provided with a plurality of bushing nozzles (not shown). Each nozzle flows down the molten glass Gm to form the glass fiber Gf. The molten glass Gm flowing down from each nozzle is formed into glass fibers Gf (glass filament) having a predetermined diameter while being stretched downward. After that, a plurality of glass fibers Gf are focused by applying a sizing agent to form glass strands.

That is, the method for producing a glass article according to the present embodiment includes a melting step of melting the glass raw material Gr in the melting furnace 2 to form the molten glass Gm, and the molten glass Gm being circulated inside the feeder 3 to form the molten glass Gm. It is provided with a supply step of supplying to the bushing 4 provided at the bottom 3a of the glass, and a molding step of flowing molten glass Gm down from the bushing nozzle provided at the bushing 4 to form the glass fiber Gf.

As shown in FIGS. 2 and 3, the feeder 3 has an electric heating element 5 that heats and retains the molten glass Gm, and a first space S1 in which the molten glass Gm is arranged and an electric heating element 5 are arranged. It is further provided with a partition plate 6 which is a partition member that completely partitions the two spaces S2. The molten glass Gm is indirectly heated via the partition plate 6. Specifically, after the partition plate 6 is heated by the heat from the electric heating element 5 and the heat from the second space S2 heated by the electric heating element 5, the molten glass Gm is heated by the heat from the partition plate 6. To. The partition member is not limited to a plate shape, but can partition the first space S1 and the second space S2, and can indirectly heat the molten glass Gm by the heat of the electric heating element 5 or the like. If there is, any shape can be selected. For example, it may be in the form of a block.

According to such a configuration, since the first space S1 and the second space S2 are independent spaces having no communicating portion with each other, a part of the electric heating element 5 is lost due to a spark or the like. However, the defective part surely stays in the second space S2. Therefore, the defective portion does not invade the first space S1 and mix into the molten glass Gm when the electric heating element 5 is defective or replaced, so that high-quality glass fiber Gf with few defects can be formed. ..

The second space S2 is a beam that is a dividing member that is continuous so as to cover the entire width of the molten glass Gm in the width direction Y orthogonal to the flow direction X of the molten glass Gm, and extends along the width direction Y in the flow direction X. It is divided into a plurality of parts by 3b. Each second space S2 accommodates one or more (two in the illustrated example) electric heating elements 5 sideways. In each second space S2, the heating temperature of the electric heating element 5 can be adjusted individually, and the temperature distribution of the flow direction X of the molten glass Gm is managed in a plurality of zones corresponding to the second space S2. It has become like. The second space S2 may be divided into a plurality of parts in the width direction Y, or may not be divided into a plurality of parts in the flow direction X.

The electric heating element 5 is a resistance heating element that is made of, for example, silicon carbide (SiC) or the like and generates heat when energized. In the present embodiment, the electric heating element 5 is a U-shaped member having a bent portion 5a and two straight portions 5b arranged in parallel via the bent portion 5a (see FIGS. 4A and 4B). Is. Two straight portions 5b of the electric heating element 5 are supported by a support block 3c arranged on one side wall portion of the feeder 3. In this state, the two straight portions 5b extend along the width direction Y so as to face each other in the flow direction X. That is, the U-order electric heating element 5 is arranged sideways along the width direction. Therefore, since the thickness of the electric heating element 5 in the vertical direction is suppressed to be thin, the volume of the second space S2 can be reduced and the heat loss in the second space S2 can be suppressed. Further, since the end portion of the electric heating element 5 (the end portion of the straight portion 5b) faces the lateral space of the feeder 3, the electric heating element 5 is replaced (pulling out work, etc.) using the lateral space of the feeder 3. Can be easily implemented. The two straight portions 5b may extend along the width direction Y so as to face each other in the vertical direction.

The length of the electric heating element 5 in the width direction Y in the second space S2 is set to a length that can cover substantially the entire width of the molten glass Gm. As a result, the electric heating element 5 is arranged directly above both ends in the width direction of the molten glass Gm and directly above the central portion in the width direction of the molten glass Gm. Therefore, the entire width of the molten glass Gm can be uniformly heated, and variations in the temperature distribution of the molten glass Gm can be suppressed. The length of the electric heating element 5 in the second space S2 in the width direction Y can be appropriately adjusted according to the amount of heat required for heat retention of the molten glass Gm. Of course, the amount of heat given to the molten glass Gm can also be adjusted by adjusting the magnitude of the current supplied to the electric heating element 5.

The partition plate 6 is continuous so as to cover the entire width of the molten glass Gm in the width direction Y so as to correspond to the second space S2, and is divided into a plurality of parts in the flow direction X. By dividing the partition plate 6 into a plurality of pieces in the flow direction X, the area and weight of each partition plate 6 are reduced, so that the partition plate 6 is less likely to bend.

The partition plate 6 is preferably made of alumina-based electroformed brick. By doing so, the heat conduction of the partition plate 6 is improved, so that the partition plate 6 is efficiently heated. As a result, the molten glass Gm can be easily heated by the heat from the partition plate 6. Further, since the partition plate 6 is less likely to be thermally deteriorated, the durability of the partition plate 6 is improved. The material of the partition plate 6 is not limited to alumina electroformed bricks, and may be, for example, fired bricks. The thickness of the partition plate 6 is preferably 5 to 100 mm.

As shown in FIGS. 4A and 4B, the electric heating element 5 is supported in the second space S2 in a state of being separated upward from the partition plate 6. Specifically, the electric heating element 5 is supported from below by a plurality of supports 7 arranged at intervals on the partition plate 6. Of course, the support mode of the electric heating element 5 is not limited to this. The shape of the support 7 is not particularly limited, and may be, for example, a polygonal pillar such as a square pillar or a cylinder. Alternatively, the support 7 is not divided into a plurality of parts, and may be, for example, a single plate-like body. The material of the support 7 is not particularly limited as long as it is a refractory material, but is formed of, for example, refractory bricks, ceramics, or the like.

Hereinafter, the feeder according to another embodiment of the present invention will be described. In the feeders according to the other embodiments, it is common that the first space and the second space are completely partitioned by a partition plate, but the structure and the like are partially changed. In the feeders according to the other embodiments, the components having the same functions or shapes as the feeders according to the first embodiment are designated by the same reference numerals in the drawings for explaining the respective embodiments. Duplicate explanations are omitted.

(Second Embodiment)
As shown in FIG. 5, the feeder 3 according to the second embodiment is different from the feeder according to the first embodiment in that the electric heating elements 5 arranged in the second space S2 are spaced in the width direction. The point is that a plurality of them (two in the illustrated example) are provided.

The electric heating element 5 is a set of a pair of electric heating elements 5 existing on both sides symmetrically with respect to the center in the width direction of the second space S2, and a plurality of sets are along the flow direction X of the molten glass Gm. They are evenly spaced. Further, each of the electric heating elements 5 has a U shape and is attached to the upper portion of the inner peripheral wall of the feeder 3. Each U-shaped electric heating element 5 is arranged sideways along the width direction.

(Third to fifth embodiments)
As shown in FIGS. 6 to 8, the feeder 3 according to the third to fifth embodiments is the feeder according to the second embodiment in which the orientation and the mounting position of the U-shaped electric heating element 5 are changed. is there.

In the feeder 3 according to the third embodiment shown in FIG. 6, the electric heating element 5 is arranged vertically along the width direction. In the feeder 3 according to the fourth embodiment shown in FIG. 7, the mounting position of the electric heating element 5 is changed from the side portion 3d on the inner peripheral wall of the feeder 3 to the upper part, and the electric heating element 5 is along the width direction. It is arranged vertically. In the feeder 3 according to the fifth embodiment shown in FIG. 8, the mounting position of the electric heating element 5 is changed from the side portion 3d on the inner peripheral wall of the feeder 3 to the upper part, and the electric heating element 5 is moved along the flow direction. It is arranged vertically.

In the present invention, the orientation and mounting position of the electric heating element 5 are not particularly limited, but from the viewpoint of reducing the volume of the second space S2 and increasing the heating efficiency by the electric heating element 5, the electric heating element 5 is used. It is preferably arranged sideways (preferably on a horizontal plane).

(Sixth Embodiment)
As shown in FIG. 9, the feeder 3 according to the sixth embodiment is different from the feeder according to the first embodiment in that the bank portion 3e is formed on the side portion 3d of the inner peripheral wall of the feeder 3. A point and a recess C for accommodating the electric heating element 5 are formed above the bank portion 3e.

A part of the side portion 3d of the inner peripheral wall projects toward the center in the width direction, and this overhanging portion forms the bank portion 3e. The partition plate 6 is provided so as to straddle between the upper ends of the respective bank portions 3e on both sides in the width direction. The dimension of the bank portion 3e overhanging is set to be longer than the dimension in the width direction of the electric heating element 5, and the electric heating element 5 is configured to be completely accommodated in the recess C. In the present embodiment, the U-shaped electric heating element 5 is attached to the upper part of the inner peripheral wall of the feeder 3 and is arranged vertically along the width direction.

(Seventh Embodiment)
As shown in FIG. 10, the feeder 3 according to the seventh embodiment is different from the feeder according to the first embodiment in that the passage P is provided between the upper portion and the side portion 3d of the inner peripheral wall of the feeder 3. It is a point where the second space S2 is formed and an expansion space Sa which extends the second space S2 to the outside of the side portion 3d in the width direction is formed through the passage P.

The partition plate 6 is provided so as to straddle between the upper ends of the side portions 3d on both sides in the width direction. The expansion space Sa is formed along the flow direction of the molten glass G, and the electric heating element 5 is housed in the upper portion thereof. In the present embodiment, the U-shaped electric heating element 5 is attached to the upper part of the inner peripheral wall of the feeder 3 and is arranged vertically along the width direction.

As described in the seventh embodiment, in the present invention, the electric heating element 5 may be arranged at a position away from directly above the molten glass Gm as long as the molten glass Gm can be heated.

(Eighth embodiment)
As shown in FIG. 11, the feeder 3 according to the eighth embodiment is the feeder according to the seventh embodiment in which the number of electric heating elements and the mounting position thereof are changed.

In the feeder 3 according to the eighth embodiment, the mounting position of the electric heating element 5 is changed from the upper part of the inner peripheral wall of the feeder 3 to the side wall surrounding the expansion space Sa. Further, the number of electric heating elements is changed from a pair (2) to 3 pairs (6), and 3 sets of a pair of electric heating elements 5 are arranged in the vertical direction in the expansion space Sa. Are evenly spaced.

(Ninth Embodiment)
As shown in FIG. 12, the feeder 3 according to the ninth embodiment is different from the feeder according to the first embodiment in that the number of electric heating elements 5 is only one. It is a point that the periphery (lower side and both sides) of the electric heating element 5 is surrounded by the partition plate 6.

A plurality of electric heating elements 5 are attached to the upper part of the inner peripheral wall of the feeder 3 at the center in the width direction, and a plurality of electric heating elements 5 are arranged at equal intervals along the flow direction of the molten glass G. The partition plate 6 includes a first portion extending in the horizontal direction below the electric heating element 5 and a second portion extending in the vertical direction on both sides of the electric heating element 5 in the width direction, and these portions. The second space S2 is divided by.

(10th Embodiment)
As shown in FIG. 13, the feeder 3 according to the tenth embodiment is changed from a U-shaped electric heating element to a rod-shaped electric heating element in the feeder according to the first embodiment.

The electric heating element 5 is continuous in the width direction from one side portion 3d to the other side portion 3d on the inner peripheral wall of the feeder 3.

The present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-mentioned effects. The present invention can be modified in various ways without departing from the gist of the present invention.

In the above embodiment, the feeder is an embodiment in which molten glass is supplied to a bushing for molding glass fibers, but the present invention is not limited to this. For example, the feeder may be in a mode of supplying molten glass to a molded body for molding a glass article such as tube glass or flat glass (including a glass roll).

In the above embodiment, the case where the electric heating element has a U-shape or a rod shape (straight line) has been described, but the shape of the electric heating element is not limited to this. For example, an arbitrary shape such as a U-shape (a shape in which the ends of heating elements having the same length extending in parallel are connected by a heating element extending vertically and the angle of the connecting part is 90 °) or a meandering shape. However, a shape capable of planar heating is preferable.

In the above embodiment, the case where the entire width of the molten glass is heated by one electric heating element extending along the width direction from the side wall portion on one side of the feeder has been described, but the arrangement mode of the electric heating element is not limited to this. .. For example, a plurality of electric heating elements may be used to heat the entire width of the molten glass. Specifically, a pair of electric heating elements may be extended symmetrically with respect to the center in the width direction from both sides in the width direction to heat the entire width of the molten glass. However, even in this case, it is preferable that at least one of the pair of electric heating elements or an electric heating element different from the pair of electric heating elements is arranged directly above the central portion in the width direction of the molten glass. ..

1 Glass article manufacturing equipment 2 Melting furnace 3 Feeder 4 Bushing 5 Electric heating element 6 Partition plate (partition member)
Gr glass raw material Gm molten glass Gf glass fiber S1 first space S2 second space X flow direction Y width direction

Claims (10)

In the feeder that distributes molten glass inside
It is characterized by including an electric heating element that heats the molten glass and a partition member that completely partitions a first space in which the molten glass is arranged and a second space in which the electric heating element is arranged. Feeder. The feeder according to claim 1, wherein at least a part of the electric heating element is arranged directly above the molten glass. The feeder according to claim 2, wherein the electric heating element is arranged sideways in the second space. The feeder according to claim 3, wherein the electric heating element extends along a width direction orthogonal to the flow direction of the molten glass. The first aspect of any one of claims 1 to 4, wherein the second space is continuous so as to cover the entire width of the molten glass in a width direction orthogonal to the flow direction of the molten glass. Feeder. The feeder according to claim 5, wherein the electric heating element is arranged directly above both ends in the width direction of the molten glass and directly above the central portion in the width direction of the molten glass. The feeder according to any one of claims 1 to 6, wherein the second space is divided into a plurality of parts in the flow direction of the molten glass. The feeder according to any one of claims 1 to 7, wherein the partition member is made of alumina-based electroformed brick. The feeder according to any one of claims 1 to 8, wherein the bottom of the feeder is provided with a bushing for molding the molten glass into glass fibers. In a method for manufacturing a glass article, which comprises a process of distributing molten glass inside a feeder.
The feeder is provided with an electric heating element for heating the molten glass, and a partition member for completely partitioning the first space in which the molten glass is arranged and the second space in which the electric heating element is arranged is provided. A method for manufacturing a characteristic glass article.

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