WO2012086467A1

WO2012086467A1 - Glass melter, glass fiber production apparatus, and glass fiber production method

Info

Publication number: WO2012086467A1
Application number: PCT/JP2011/078792
Authority: WO
Inventors: 鎌太郎小川; 中村　幸一; 平山　紀夫
Original assignee: 日東紡績株式会社
Priority date: 2010-12-21
Filing date: 2011-12-13
Publication date: 2012-06-28
Also published as: JPWO2012086467A1; TW201240933A; JP5867413B2

Abstract

A glass melting furnace is heated to the melting point of silica or hotter and the melting time of glass material is reduced, and the amount of insufficiently melted glass material is reduced. A glass fiber production apparatus (1) is provided with: a glass melting furnace (11) provided with a floor (12) and a side wall (13), and having a molten glass outlet (15) formed in the floor (12); an injection opening (19) that injects glass material into the glass melting furnace (11) and covers the glass melting furnace (11); a casing (18) in which a discharge opening (23), for discharging molten glass emitted from the outlet (15) of the glass melting furnace (11), is formed; and heating electrodes (14) for heating the molten glass in the glass melting furnace (11) using an electric current, and positioned so as to stick into the glass melting furnace from the roof (18a) of the casing (18). Therein, the inner surface of the side wall (13) and the floor (12) of the glass melting furnace (11) is coated with boron nitride. Additionally, the electric current of the heating electrodes (14) causes the glass material injected into the glass melting furnace (11) to be directly heated and melted.

Description

Glass melting apparatus, glass fiber manufacturing apparatus, and glass fiber manufacturing method

The present invention relates to a glass melting apparatus for melting a glass raw material, a glass fiber manufacturing apparatus and a glass fiber manufacturing method for manufacturing glass fiber using the glass melting apparatus.

A glass fiber manufacturing apparatus for manufacturing glass fibers is a fiber melting furnace that melts glass raw materials, a forerhas into which molten glass drawn from the glass melting furnace outlet is introduced, and a molten glass introduced into the foreher. And a fiberizing device for spinning glass fibers. In this glass melting furnace, refractory bricks such as chrome bricks and zirconia bricks are generally used. In recent years, with the aim of improving the glass melting energy efficiency, studies are being made to suppress energy consumption by melting at a higher temperature in a shorter time than the general glass melting temperature of 1400-1500 ° C. . However, in such a high temperature range, the brick used as the furnace melting material of the glass melting furnace is significantly eroded by the molten glass. Therefore, with the conventional melting furnace, the melting efficiency is increased by raising the furnace temperature. I can't raise it.

Japanese Patent Laid-Open No. 06-329422 JP 2003-183031 A

Since silica, which is the main component of the glass composition, has a high melting point and is difficult to melt, heating at 1400-1500 ° C. takes a long time to melt the silica, and also causes unsolved problems.

Patent Document 1 describes that heating at 1550 to 1600 ° C. is necessary for melting high-strength glass mainly composed of MgO (magnesia), Al ₂ O ₃ (alumina), and SiO ₂ (silica). However, even heating in this temperature range requires several hours for melting, and the melting efficiency cannot be increased.

As a result of extensive studies, the present inventor has found that the melting efficiency can be dramatically increased by heating to 1723 ° C. or higher, which is the melting point of silica.

Therefore, the present invention provides a glass melting apparatus, a glass fiber manufacturing apparatus, and a glass fiber manufacturing method capable of shortening the melting time of the glass raw material by heating above the melting point of silica and reducing unmelted glass raw material. For the purpose.

A glass melting apparatus according to the present invention comprises a glass melting furnace having a bottom wall and a side wall, and a molten glass outlet is formed on the bottom wall, covers the glass melting furnace, and glass raw material vertically above the glass melting furnace And a casing formed with a discharge port for discharging the molten glass drawn from the outlet vertically below the outlet, and inserted into the glass melting furnace from the ceiling of the casing by energization. And a heating electrode for heating the molten glass in the glass melting furnace, wherein the bottom wall and the inner surface of the side wall are coated with boron nitride.

According to the glass melting apparatus of the present invention, the inner surfaces of the bottom wall and the side wall are coated with boron nitride having non-conductivity, so that the electrodes are energized to melt the glass raw material in the glass melting furnace. When an electric current is supplied to the molten glass (glass melt), it is possible to prevent the electric current from erroneously flowing from the molten glass to the conductive material constituting the furnace body and the casing. In addition, since the bottom wall and the inner surface of the side wall are coated with boron nitride, even if the molten glass in the glass melting furnace is heated to a high temperature, the carbon dioxide generated when the glass raw material supplied from the inlet is vitrified. It is possible to suppress the glass melting furnace from being oxidized and sublimated by the reaction between the oxygen source such as the bottom wall inner surface and the side wall inner surface. In general, the glass melting furnace is made of a material having a melting point of 2000 ° C. or higher in a non-oxidizing atmosphere, so that the glass raw material can be melted at a temperature higher than the melting point of silica, which is the main raw material of glass. Therefore, the melting time of the glass raw material can be shortened, energy saving can be achieved, and unmelted glass raw material can be reduced. In addition, by energizing the heating electrode inserted in the glass melting furnace, the molten glass in the glass melting furnace can be directly heated, and the molten glass can be heated at an arbitrary position in the glass melting furnace. For this reason, regardless of the shape and size of the glass melting furnace, the molten glass can be efficiently heated, and in particular, it can be applied to a large glass melting furnace.

In this case, the casing further includes an inert gas supply means for supplying an inert gas, and the casing includes an inert gas inlet for introducing the inert gas supplied from the inert gas supply means into the casing, and the casing. It is preferable that an inert gas discharge port for discharging the introduced inert gas is formed. In this way, by introducing an inert gas into the casing, the entire glass melting furnace is isolated from the atmosphere, so that the bottom wall and side walls, the heating electrode, and the like are also prevented from being oxidized and sublimated. Can do. For this reason, even if a molten glass is heated to high temperature, it can suppress that the service life of a glass melting furnace falls.

Moreover, it arrange | positions between the 1st area | region of the glass melting furnace arrange | positioned perpendicularly | vertically below an inlet, and the 2nd area | region of the glass melting furnace in which an outlet is formed, and partitions the upper part in the furnace of a glass melting furnace It is preferable to further have an upper partition plate. In this way, by providing the upper partition plate in the glass melting furnace, the unmelted glass is prevented from being drawn out from the outlet through the fast flow in the upper part of the furnace, and the moving path of the molten glass in the glass melting furnace Therefore, the residence time of the molten glass in the glass melting furnace can be lengthened. Thereby, since the unmelted residue of the glass raw material can be further reduced, a high-quality glass fiber can be produced.

A glass fiber manufacturing apparatus according to the present invention is introduced into any one of the glass melting apparatuses described above, a storage tank into which molten glass disposed below the glass melting furnace and drawn from the outlet is introduced, and the storage tank. And a fiberizing apparatus for fiberizing and spinning the molten glass.

According to the glass fiber manufacturing apparatus according to the present invention, since the glass melting apparatus described above is provided, the time for melting the glass raw material in the lath melting apparatus can be shortened and unmelted glass raw material can be reduced. Can produce glass fiber quickly and with high quality.

A glass fiber manufacturing method according to the present invention is a glass fiber manufacturing method using the above-described glass fiber manufacturing apparatus, in which a glass raw material is charged into a glass melting furnace through a charging port, and a heating electrode is energized to generate glass. Melting the glass raw material put into the melting furnace, drawing the molten glass from the outlet and introducing it into the storage tank, and fiberizing the molten glass introduced into the storage tank with a fiberizer to produce glass fibers Features.

According to the glass fiber manufacturing method according to the present invention, the time for melting the glass raw material in the glass melting apparatus can be shortened, and the remaining unmelted glass raw material can be reduced, so that quick and high-quality glass fiber is manufactured. can do.

In this case, the inside of the casing is preferably an inert gas atmosphere. Thus, by making the inside of a casing into inert gas atmosphere, since the whole glass melting furnace is isolated from air | atmosphere, it can suppress that a glass melting furnace and an electrode oxidize and sublimate. For this reason, even if a molten glass is heated at high temperature, it can suppress that the service life of a glass melting furnace falls.

Also, the molten glass can be heated to 1700 to 2000 ° C. by energizing the heating electrode. By heating the molten glass to 1700 to 2000 ° C. in this way, the melting time of the glass raw material can be drastically shortened because it is melted by the single silica as the main component of the glass.

According to the present invention, since the glass melting apparatus can be heated to the melting point of silica or more, the melting time of the glass raw material can be shortened and the unmelted glass raw material can be reduced.

It is a schematic diagram of the glass fiber manufacturing apparatus which concerns on 1st Embodiment. It is a top view of a glass melting furnace. It is a schematic diagram of the glass fiber manufacturing apparatus which concerns on 2nd Embodiment. It is a schematic diagram of the glass fiber manufacturing apparatus which concerns on 3rd Embodiment. It is a schematic diagram of the glass fiber manufacturing apparatus which attached the vacuum degassing furnace.

Hereinafter, preferred embodiments of a glass melting apparatus, a glass fiber manufacturing apparatus, and a glass fiber manufacturing method according to the present invention will be described in detail with reference to the drawings. In all the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a schematic diagram of a glass fiber manufacturing apparatus according to the first embodiment. As shown in FIG. 1, the glass fiber manufacturing apparatus 1 which concerns on 1st Embodiment is provided with the glass melting apparatus 10 mounted in the floor 2, and the fiberization equipment 30 arrange | positioned under the floor 2. As shown in FIG. .

The glass melting apparatus 10 includes a glass melting furnace 11 that melts a glass raw material such as a glass raw material powder or a glass lump, and a casing 18 that covers the glass melting furnace 11. The glass raw material powder is a powdery mixture of clay, limestone, dolomite, colemanite, silica sand, alumina, calcium carbonate, sodium carbonate, etc., and the glass lump is once cooled with molten glass obtained by melting the glass raw material powder. Solid marbled or cullet shaped.

The glass melting furnace 11 is formed in a box shape opened upward by a bottom wall 12 and a side wall 13 erected on the bottom wall 12. The bottom wall 12 and the side wall 13 are made of a furnace material such as molybdenum, and the inner surfaces of the bottom wall 12 and the side wall 13 are covered with boron nitride.

Such a glass melting furnace 11 is divided by an upper partition plate 16 and is arranged in a first region A for melting the glass raw material placed and disposed below the inlet 19 into which the glass raw material is introduced. The second region B in which the outlet 15 for drawing the molten glass from the glass melting furnace 11 is formed on the bottom wall 12 is formed. The second region B is entirely or partially higher than the first region A in order to block impurities accumulated at the bottom of the furnace body and lengthen the moving path of the molten glass. For this reason, the bottom wall 12 of the glass melting furnace 11 is formed with a rising portion 12a rising from the first region A to the second region B at the boundary between the first region A and the second region B. The inner surface of the outlet 15 is also covered with boron nitride.

The upper partition plate 16 is installed on the upper part of the glass melting furnace 11 so that the upper surface is higher than the molten glass liquid level and the lower surface does not touch the bottom wall 12, and near the liquid surface of the molten glass (the glass melting furnace 11 This is a partition plate that allows the molten glass to pass through only from the bottom of the furnace of the glass melting furnace 11. The upper partition plate 16 is made of a furnace material such as molybdenum similarly to the bottom wall 12 and the side wall 13 of the glass melting furnace 11, and the surface of the upper partition plate 16 is covered with boron nitride. The upper partition plate 16 is formed in a flat plate shape that abuts against a pair of opposing side walls 13 to partition the first region A and the second region B, and a space is formed between the bottom wall 12 and the upper partition plate 16. Yes. For this reason, the molten glass melted in the first region A can move to the second region B by diving in a space formed below the upper partition plate 16.

A plurality of heating electrodes 14 are inserted into the glass melting furnace 11 from above. The heating electrode 14 is made of a material (high temperature resistant material) that can withstand high temperatures such as molybdenum and tungsten, and is connected to a power source 17 that supplies electricity. The heating electrode 14 is preferably cylindrical from the viewpoint of insertion / extraction with respect to the glass melting apparatus 10, but can be deformed into various shapes without particular limitation. The glass raw material charged into the glass melting furnace 11 can be heated and melted by directly energizing the glass raw material with the heating electrode 14. The glass melting furnace 11 is also called a boosting furnace because it is heated by a heating electrode 14 inserted in the glass melting furnace 11, and is mainly a direct melt method (DM method) for melting glass raw material powder. Used for. However, you may use this glass melting furnace 11 for the marble melt method (MM method) etc. which fuse | melt the glass raw material of a glass soul.

If there are two or more heating electrodes 14, the number and arrangement thereof can be arbitrarily selected. However, in view of the fact that the region surrounded by the heating electrode 14 is heated most, it is preferable to select the heating electrode 14 so as to surround the charging port 19 in the horizontal direction. FIG. 2 is a top view of the glass melting furnace shown in FIG. For example, as shown in FIG. 2 (a), two heating electrodes 14 may be arranged in the first region A so as to sandwich the insertion port 19, and as shown in FIG. In the region A, three heating electrodes 14 may be disposed at a position surrounding the charging port 19, and as shown in FIG. 2C, two heating electrodes 14 are positioned at a position sandwiching the charging port 19 in the first region A. For example, two heating electrodes 14 may be arranged in the second region B. Thus, by arranging the heating electrode 14 at a position sandwiching the charging port 19, the glass raw material charged into the glass melting furnace 11 from the charging port 19 can be efficiently heated and melted. In addition, by disposing the heating electrode 14 in the second region B, it is possible to prevent the temperature of the molten glass from decreasing in the second region B without using other heating means. The temperature of the molten glass drawn out from the outlet 15 can be adjusted.

Further, since the heating electrode 14 has a property that electricity easily flows at the tip portion thereof, it is preferable to arrange the tip portion of the heating electrode 14 at a position where the glass raw material to be charged is accumulated. For example, since the glass raw material of the glass raw material powder is collected near the liquid surface of the molten glass, it is preferable to arrange the tip of the heating electrode 14 near the liquid surface of the molten glass. It is preferable to arrange the tip of the heating electrode 14 at the bottom of the glass melting furnace 11 in order to sink to the bottom of the furnace.

The casing 18 is disposed above the glass melting furnace 11 in the vertical direction, and is disposed on the top wall 18 a serving as the ceiling of the casing 18, the side wall 18 b covering the periphery of the glass melting furnace 11, and the lower side in the vertical direction of the glass melting furnace 11. The bottom wall 18c is formed in a box shape and placed on the floor 2.

The top wall 18a holds a plurality of heating electrodes 14 inserted into the glass melting furnace 11, and the number and arrangement of the heating electrodes 14 can be easily changed by replacing the top wall 18a.

In the top wall 18 a, a charging port 19 for feeding a glass material into the glass melting furnace 11 is formed above the first region A in the glass melting furnace 11 in the vertical direction. A screw charger 20 is connected to the charging port 19 for supplying a glass raw material to be charged into the glass melting furnace 11.

In the side wall 18b, an inert gas inlet 21 for introducing an inert gas into the casing 18 is formed at a position higher than the liquid level of the molten glass. An inert gas supply device 22 that supplies an inert gas to be introduced into the casing 18 is connected to the inert gas inlet 21. The gas supplied from the inert gas supply device 22 is not particularly limited as long as it is a non-oxidizing gas. For example, argon gas or nitrogen gas can be used, and among them, continuously at low cost. Nitrogen gas is preferable in terms of stable supply.

In the bottom wall 18c, a discharge port 23 for discharging the molten glass drawn out from the outlet 15 is formed below the outlet 15 of the glass melting furnace 11 in the vertical direction. Further, the discharge port 23 can discharge the inert gas simultaneously with the discharge of the molten glass.

In the casing 18, a heat insulating material such as a refractory brick or a heat resistant board for insulating the glass melting furnace 11 is inserted.

The floor 2 is formed with a floor hole 3 for introducing the molten glass drawn from the outlet 15 of the glass melting furnace 11 into each fiberizing equipment 30.

The fiberizing facility 30 is a facility for fiberizing the molten glass drawn from the outlet 15 of the glass melting furnace 11. This fiberizing equipment 30 includes a forehearth 31 into which the molten glass drawn from the outlet 15 is introduced, a bushing 32 for forming a large number of filaments from the molten glass in the forehearth 31, and a high speed by drawing the filament from the bushing 32. , A rotating drum 33 that winds up, an applicator 37 that applies a sizing agent to each filament drawn from the bushing 32, and a focusing roller 34 that focuses each filament.

Fore Haas 31 is a storage tank in which the molten glass drawn out from the outlet 15 is introduced and the temperature of the molten glass is adjusted to adjust the viscosity of the molten glass to be easily fiberized. The forehearth 31 is disposed below the floor hole 3 in the vertical direction, and is formed with an upper opening 35 into which the molten glass drawn from the outlet 15 is introduced. The forehearth 31 is opened to the atmosphere by the upper opening 35. In addition, the forehearth 31 includes a heating means for adjusting the temperature of the molten glass. This heating means may be, for example, an electric heater 36 suspended from the ceiling surface of the forehearth 31, and any heating means capable of adjusting the temperature of molten glass such as a gas burner in place of the electric heater 36. May be used.

The bushing 32 is provided at the bottom of the forehearth 31, and a large number (for example, about 100 to 4000) of nozzles (not shown) for spinning are formed. The bushing 32 includes a heating means (not shown) for adjusting the temperature of the molten glass. This heating means is for generating resistance heat by energization. For this reason, the bushing 32 is formed of an electrothermal member that generates heat when energized, and is made of, for example, platinum or a platinum alloy.

Next, a method for producing glass fibers by the glass fiber production apparatus 1 according to this embodiment will be described.

First, after the inside of the casing 18 is evacuated or at least decompressed with a vacuum pump to remove oxygen present in the casing 18, the inert gas supplied from the inert gas supply device 22 is supplied from the inert gas inlet 21. The operation of introducing into the casing 18 is repeated several times until the oxygen concentration in the casing 18 is at least 1% or less, and the inside of the casing 18 is made an inert gas atmosphere. Note that the gas filled in the casing 18 before the inert gas is introduced and the inert gas introduced into the casing 18 are discharged from the discharge port 23.

Next, the glass raw material is supplied from the screw charger 20, the glass raw material is supplied from the charging port 19 to the first region A of the glass melting furnace 11, electricity is supplied from the power source 17, and the heating electrode 14 is energized, The glass raw material thrown into the 1st area | region A is heat-melted. When the glass melting apparatus 10 is heated up (started up), since the glass melt furnace 11 is not filled with molten glass, it is difficult for the heating electrode 14 to be energized. It is preferable to melt the glass raw material charged into the melting furnace 11. At this time, the molten glass is heated to 1700 to 2000 ° C. by energization by the heating electrode 14. Thereby, the melting of the silica contained in the glass raw material is promoted, the glass raw material is rapidly melted, and the unmelted glass raw material is eliminated. Since the inside of the glass melting furnace 11 and the casing 18 is an inert gas atmosphere, even if the molten glass is heated to 1700 to 2000 ° C., the glass melting furnace 11 and the heating electrode 14 are oxidized and sublimated. Furthermore, since the inner surfaces of the bottom wall 12 and the side wall 13 are coated with boron nitride, oxygen such as carbon dioxide gas generated from the glass raw material into which the glass melting furnace 11 and the heating electrode 14 are charged. Oxidation and sublimation by the source can be suppressed.

In addition, the forehearth 31 and the bushing 32 of the fiberizing equipment 30 are also heated, and the heating temperature of the forehearth 31 and the bushing 32 is appropriately adjusted so that the molten glass has a temperature that facilitates fiberization according to the glass composition of the glass fiber to be manufactured. Keep it.

Then, the molten glass melted in the first region A moves from the first region A to the second region B through the rising portion 12a of the bottom wall 12 while diving in the space formed below the upper partition plate 16. Then, it is pulled out vertically downward from an outlet 15 formed in the bottom wall 12 of the second region B. The molten glass drawn out from the outlet 15 passes through the outlet 23 formed in the casing 18, the floor hole 3 formed in the floor 2, and the upper opening 35 formed in the forehearth 31 of the fiberizing equipment 30. The glass filament is drawn out from a large number of nozzles of a bushing 32 provided at the bottom of the forehearth 31. The glass filaments drawn out from a number of nozzles of the bushing 32 are coated with a sizing agent by an applicator 37 and wound by a rotating drum 33 that rotates at a high speed while focusing a number of glass filaments by a focusing roller 34. Glass fibers in which glass filaments are bundled are produced.

As described above, according to the first embodiment, since the inner surfaces of the bottom wall 12 and the side wall 13 are coated with boron nitride, the heating electrode 14 is energized to melt the glass raw material, and the molten glass When a current is supplied to the glass, it is possible to prevent a current from flowing erroneously from the molten glass to the conductive material constituting the glass melting furnace 11 and the casing 18. Further, since the inner surfaces of the bottom wall 12 and the side wall 13 are coated with boron nitride, the glass raw material supplied from the inlet 19 is vitrified even when the molten glass in the glass melting furnace 11 is heated to a high temperature. It is possible to prevent the glass melting furnace 11 from being oxidized and sublimated due to the reaction between the oxygen source such as carbonic acid generated at the inner surface and the inner surface of the bottom wall 12 and the inner surface of the side wall 13. Since the glass melting furnace 11 is made of a material having a melting point of 2000 ° C. or higher in a non-oxidizing atmosphere, the glass melting furnace 11 is not corroded by the molten glass, and the silica which is the main raw material of glass is used. Since the glass raw material can be melted at a temperature higher than the melting point, the melting time of the glass raw material can be shortened, energy saving can be achieved, and unmelted glass raw material (unmelted glass raw material) Can be reduced.

And by supplying electricity to the heating electrode 14 inserted in the glass melting furnace 11, the molten glass in the glass melting furnace 11 can be directly heated, and the molten glass is heated at an arbitrary position in the glass melting furnace 11. be able to. For this reason, regardless of the shape and size of the glass melting furnace 11, the molten glass can be efficiently heated, and in particular, can be applied to the large-sized glass melting furnace 11.

Furthermore, since the entire glass melting furnace 11 is isolated from the atmosphere by introducing an inert gas into the casing 18, the glass melting furnace 11 and the heating electrode 14 are also prevented from being oxidized and sublimated. Can do. For this reason, even if a molten glass is heated to high temperature, it can suppress that the service life of the glass melting furnace 11 falls.

Further, by heating the molten glass to 1700 to 2000 ° C. in the glass melting furnace 11, it is melted with silica alone, which is the main component of the glass, so that the melting time of the glass raw material can be dramatically shortened.

Further, the second region B is entirely or partially made higher than the first region A to form the rising portion 12a of the bottom wall 12 between the first region A and the second region B, so that the furnace body Impurities that accumulate at the bottom can be dammed and the movement path of the molten glass in the glass melting furnace 11 can be extended, so that the residence time of the molten glass in the glass melting furnace 11 can be increased. Thereby, since the unmelted residue of the glass raw material can be further reduced, a high-quality glass fiber can be produced.

Similarly, since the upper partition plate 16 is provided between the inlet 19 and the outlet 15 of the glass melting furnace 11, the movement path of the molten glass in the glass melting furnace 11 can be extended. The residence time of the molten glass in the inside becomes longer, and the unmelted glass raw material is further reduced. Furthermore, since the upper partition plate 16 can block the bubbles that have floated near the liquid surface of the molten glass and prevent the bubbles from moving to the second region B, the molten glass containing bubbles can be prevented from flowing into the second region B. It can suppress that it moves to and is pulled out from the outlet 15. Thereby, the high quality glass fiber without the melt | dissolution residue of a glass raw material and a bubble can be manufactured.

[Second Embodiment]
FIG. 3 is a schematic view of a glass fiber manufacturing apparatus according to the second embodiment. As shown in FIG. 3, the glass fiber manufacturing apparatus 40 according to the second embodiment is basically the same as the glass fiber manufacturing apparatus 1 according to the first embodiment, and only the configuration of the forehearth is the first embodiment. It differs from the glass fiber manufacturing apparatus 1 which concerns on this. For this reason, in the following description, only a different point from 1st Embodiment is demonstrated and description of the same point as 1st Embodiment is abbreviate | omitted.

The forehearth 41 of the second embodiment is similar to the forehearth 31 of the first embodiment, and the molten glass drawn from the outlet 15 of the glass melting furnace 11 is introduced and the temperature of the molten glass is adjusted. It is a storage tank that adjusts the molten glass to a viscosity that facilitates fiberization. For this reason, the forehearth 41 is arranged vertically below the floor hole 3, and an upper opening 35 into which the molten glass drawn from the outlet 15 is introduced is formed to adjust the temperature of the molten glass. Heating means (electric heater 36) is provided.

In addition, an inert gas introduction port 42 for introducing an inert gas into the forehearth 41 is formed on the side wall of the forehearth 41. An inert gas supply device 43 that supplies the active gas is connected. The gas supplied from the inert gas supply device 43 is not particularly limited as long as it is a non-oxidizing gas. For example, argon gas or nitrogen gas can be used. Nitrogen gas is preferable in terms of stable supply. In this case, the upper opening 35 of the forehearth 41 also functions as an inert gas discharge port for discharging the inert gas introduced into the casing 18.

When the glass fiber is manufactured by the glass fiber manufacturing apparatus 40 configured as described above, the inert gas supplied from the inert gas supply apparatus 43 is introduced into the forehearth 41 from the inert gas inlet 42, The interior of the forehearth 41 is set to an inert gas atmosphere. Note that the gas filled in the forehearth 41 before introducing the inert gas or the inert gas introduced into the forehearth 41 is discharged from the upper opening 35.

As described above, the operation of introducing the inert gas into the forehearth 41 after removing the oxygen existing in the forehearth 41 by making the inside of the forehearth 41 into a vacuum state or at least a reduced pressure state with a vacuum pump is performed. By repeating several times until it becomes at least 1% or less, the interior of the forehearth 41 is isolated from the atmosphere, and therefore the molten glass introduced into the forehearth 41 from the glass melting furnace 11 is also isolated from oxygen, and therefore the oxygen of the molten glass Deterioration can be suppressed. Thereby, it can use suitably for manufacture of glass seed | species like oxynitride glass in which the non-oxidizing atmosphere until fiberization is requested | required.

[Third Embodiment]
FIG. 4 is a schematic diagram of a glass fiber manufacturing apparatus according to the third embodiment. As shown in FIG. 4, the glass fiber manufacturing apparatus 50 according to the third embodiment is basically the same as the glass fiber manufacturing apparatus 1 according to the first embodiment, and only the configuration of the glass melting furnace is the first. It differs from the glass fiber manufacturing apparatus 1 which concerns on embodiment. For this reason, in the following description, only a different point from 1st Embodiment is demonstrated and description of the same point as 1st Embodiment is abbreviate | omitted.

The glass melting furnace 51 of the third embodiment is a so-called boosting furnace in which a plurality of heating electrodes 14 are inserted from above, similarly to the first embodiment. The glass melting furnace 51 is formed in a box shape opened upward by a flat bottom wall 52 and a side wall 53 standing on the bottom wall 52. The bottom wall 52 and the side wall 53 are made of a furnace material such as molybdenum, and the inner surfaces of the bottom wall 52 and the side wall 53 are covered with boron nitride.

Similar to the glass melting furnace 11 of the first embodiment, such a glass melting furnace 51 is disposed by being placed vertically below the charging port 19 into which the glass raw material is charged, which is partitioned by the upper partition plate 55. A first region A for melting the glass raw material formed and a second region B from which the molten glass is drawn are formed.

The bottom wall 52 of the second region B is formed with an outlet 54 for drawing molten glass from the glass melting furnace 51, and the first region A and the second region B are partitioned by the upper partition plate 55. The lower partition plate 56 is disposed between the upper partition plate 55 and the outlet 54 in the second region B. The inner surface of the outlet 54 is also covered with boron nitride.

Similar to the upper partition plate 16 of the first embodiment, the upper partition plate 55 is an upper portion of the glass melting furnace 51 and partitions the vicinity of the liquid surface of the molten glass from the bottom of the glass melting furnace 51 only. It is a partition plate to pass through. The upper partition plate 55 is made of a furnace material such as molybdenum like the bottom wall 52 and the side wall 53 of the glass melting furnace 51, and the surface of the upper partition plate 55 is covered with boron nitride. The upper partition plate 55 is formed in a flat plate shape that abuts against a pair of opposing side walls 53 to partition the first region A and the second region B, and a space is formed between the bottom wall 52 and the upper partition plate 55. Yes. For this reason, the molten glass melted in the first region A can move to the second region B by diving in a space formed below the upper partition plate 55.

The lower partition plate 56 is a partition plate that allows the molten glass to pass only from the upper part of the glass melting furnace 51 by dividing the inner bottom of the glass melting furnace 51. The lower partition plate 56 is made of a furnace material such as molybdenum similarly to the bottom wall 52 and the side wall 53 of the glass melting furnace 51, and the surface of the lower partition plate 56 is coated with boron nitride. The lower partition plate 56 is formed into a flat plate shape that comes into contact with the pair of opposing side walls 53 and the bottom wall 52 to partition the first region A and the second region B. From the liquid surface height of the molten glass Is also low. For this reason, the molten glass melted in the first region A can move to the second region B by passing over the lower partition plate 56.

The lower partition plate 56 is disposed on the upper partition plate 55 side when viewed from the outlet 54 in the second region B. For this reason, the molten glass melted in the first region A first dives in the space formed below the upper partition plate 55, and then passes over the lower partition plate 56, thereby drawing in the second region B. It moves to the outlet 54 side and is pulled out from the outlet 54.

When the glass fiber is manufactured by the glass fiber manufacturing apparatus 50 configured as described above, the inside of the casing 18 is set to an inert gas atmosphere as in the first embodiment, and the first of the glass melting furnace 51 is introduced from the inlet 19. A glass material is charged into the region A, and the heating electrode 14 is energized to heat and melt the glass material charged into the first region A.

Then, the molten glass melted in the first region A moves through the space formed below the upper partition plate 16 and moves from the first region A to the second region B, and the lower partition plate in the second region B. The upper portion 56 is pulled out vertically downward from an outlet 54 formed in the bottom wall 52 of the second region B, and is introduced into the forehearth 31.

As described above, by providing the lower partition plate 56 in the glass melting furnace 51, impurities accumulated in the bottom of the furnace body without providing a step in the bottom wall 52 itself of the glass melting furnace 51 as in the first embodiment. Can be prevented from being drawn out from the outlet 54, and the moving path of the molten glass in the glass melting furnace 51 can be extended. Thereby, time for fully melting the glass raw material in the glass melting furnace can be secured.

In addition, this invention is not limited to the said embodiment, A various change is possible.

For example, although the glass melting furnace 11 has been described as being covered with the casing 18 in the above embodiment, oxidation problems such as the glass melting furnace 11 and the heating electrode 14 can be tolerated, and the glass melting furnace 11 and the heating electrode 14 are acceptable. Is not necessarily covered with the inert gas atmosphere, it is not always necessary to cover the glass melting furnace 11 with the casing 18.

Moreover, in the said embodiment, although demonstrated as what introduce | transduces the molten glass withdrawn from the outlet 15 directly into the forehearth 31, the molten glass withdrawn from the outlet 15 like the glass fiber manufacturing apparatus 60 shown in FIG. You may introduce | transduce glass into the forehearth 31 via intermediate tanks, such as the molten glass storage tank 61 and the pressure reduction degassing furnace 62. FIG. The vacuum degassing furnace 62 hermetically covers the furnace 63 into which the molten glass is introduced with a casing 64 and depressurizes the inside of the casing 64 with a vacuum pump 65, thereby removing the molten glass introduced into the furnace 63. It encourages bubbles.

In the third embodiment, the lower partition plate 56 is described as being fixed to the glass melting furnace 51. However, the lower partition plate 56 is attached to the glass melting furnace 51 so as to be movable upward in the vertical direction. It may be a thing. And when changing the composition of the glass, it is possible to move the molten glass in the first region A to the outlet 54 along the bottom surface of the glass melting furnace 51 by moving the lower partition plate 56 upward in the vertical direction. Therefore, the time for replacing the glass composition can be drastically improved.

The present invention can be used as a glass melting apparatus for melting glass raw materials, a glass fiber manufacturing apparatus for manufacturing glass fibers using this glass melting apparatus, and a glass fiber manufacturing method.

DESCRIPTION OF SYMBOLS 1 ... Glass fiber manufacturing apparatus, 2 ... Floor, 3 ... Floor hole, 10 ... Glass melting apparatus, 11 ... Glass melting furnace, 12 ... Bottom wall, 12a ... Rising part, 13 ... Side wall, 14 ... Heating electrode, 15 ... Drawer outlet, 16 ... upper partition plate, 17 ... power source, 18 ... casing, 18a ... top wall, 18b ... side wall, 18c ... bottom wall, 19 ... inlet, 20 ... screw charger, 21 ... inert gas inlet, 22 ... inert gas supply device (inert gas supply means), 23 ... discharge port (inert gas discharge port), 30 ... fiberizing equipment, 31 ... fore hearth, 32 ... bushing (fibering device), 33 ... rotating drum ( (Fibering device), 34 ... focusing roller (fibering device), 35 ... upper opening, 36 ... electric heater, 37 ... applicator, 40 ... glass fiber manufacturing device, 41 ... fore hearth, 42 ... inert gas inlet, 43 Inert gas supply device, 50 ... glass fiber production device, 51 ... glass melting furnace, 52 ... bottom wall, 53 ... side wall, 54 ... outlet, 55 ... upper partition plate, 56 ... lower partition plate, 60 ... glass fiber production Equipment: 61 ... Molten glass storage tank, 62 ... Vacuum degassing furnace, 63 ... Furnace, 64 ... Casing, 65 ... Vacuum pump, A ... First region, B ... Second region.

Claims

A glass melting furnace comprising a bottom wall and a side wall, wherein a molten glass outlet is formed in the bottom wall;
Covering the glass melting furnace, a glass raw material inlet is formed vertically above the glass melting furnace, and a discharge outlet for discharging the molten glass drawn from the outlet vertically below the outlet A formed casing;
An electrode for heating which is inserted into the glass melting furnace from the ceiling of the casing and heats the molten glass in the glass melting furnace by energization;
Have
The glass melting apparatus, wherein inner surfaces of the bottom wall and the side wall are coated with boron nitride.
An inert gas supply means for supplying an inert gas;
The casing is
An inert gas inlet for introducing the inert gas supplied from the inert gas supply means into the casing;
An inert gas outlet for discharging the inert gas introduced into the casing;
The glass melting apparatus according to claim 1, wherein the glass melting apparatus is formed.
The glass melting furnace is disposed between a first region of the glass melting furnace disposed vertically below the charging port and a second region of the glass melting furnace in which the outlet is formed. The glass melting apparatus according to claim 1, further comprising an upper partition plate that partitions the upper portion.
A glass melting apparatus according to any one of claims 1 to 3,
A storage tank into which the molten glass placed under the glass melting furnace and drawn from the outlet is introduced;
A fiberizing apparatus for fiberizing and spinning molten glass introduced into the storage tank;
An apparatus for producing glass fiber, comprising:
It is a manufacturing method of the glass fiber using the glass fiber manufacturing apparatus of Claim 4,
Glass raw material is charged into the glass melting furnace from the charging port,
Energizing the heating electrode to melt the glass raw material charged into the glass melting furnace,
Pulling out the molten glass from the outlet and introducing it into the storage tank,
A glass fiber manufacturing method, wherein the molten glass introduced into the storage tank is fiberized by the fiberizing apparatus to manufacture glass fibers.
6. The glass fiber manufacturing method according to claim 5, wherein the inside of the casing is filled with an inert gas atmosphere.
The method for producing glass fiber according to claim 5 or 6, wherein the molten glass is heated to 1700 to 2000 ° C by energization of the heating electrode.