JPH09188527A - Temperature control device of glass discharge pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the temperature control device of a glass discharge pipe, capable of securing the high response of temperature control without causing the increase in the weights of plate-like electrodes, capable of securing rigidity capable of enduring loads due to the thermal expansion of the glass discharge pipe, and further capable of controlling the level of the opening of the glass discharge pipe without relating to the changes in temperature conditions due to the differences of glass materials, etc. SOLUTION: This temperature control device of the glass discharge pipe is provided with electrodes for electrically heating the vertically extended region of the glass discharge pipe 3, when molten glass heated at a described temperature is discharged on a receiving mold 6 from a glass-melting container 1 disposed in a glass-melting oven through the glass discharge pipe, and plate-like electrodes 9, 10 are mounted on the opening part of the glass discharge pipe to maintain the temperature of the discharged glass to a prescribed value. Therein, the plate-like electrodes 9, 10 are at least held and fixed at a prescribed controlled level based on the glass-receiving mold in a glass-received state, and the plate-like electrodes are formed in such shapes that the cross section coefficients of the electrodes increase in the perpendicular direction of the glass-discharging pipe so as to endure a stress loaded by the thermal expansion of the glass discharge pipe 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portion of a glass outflow pipe extending in a vertical direction when it is drawn out from a glass melting container installed in a glass melting furnace into a mold through a glass outflow pipe. A temperature control device for a glass outflow pipe, in which an electrode for electrically heating is arranged in a region and a plate-like electrode is attached to the opening of the glass outflow pipe to maintain the glass temperature at the time of derivation at a required value. Is.

[0002]

2. Description of the Related Art Conventionally, a glass outflow pipe made of platinum or a platinum alloy for flowing out molten glass to a receiving mold is supplied with an electric current directly to bring the temperature of the flowing molten glass to a predetermined value. Temperature control device to maintain (for example, Japanese Patent Publication No.
A device disclosed in Japanese Patent Laid-Open No. 0-11742) is known. However, in such a temperature control device, since the opening (outlet) of the outflow pipe is exposed to the outside,
There is a problem that the temperature of the molten glass may be lowered and crystallization may occur, or it may be difficult to start the outflow of the glass or the control range of the outflow amount of the glass once may be limited.

Therefore, for the purpose of preventing the temperature drop at the opening of the outflow pipe, for example, a device disclosed in Japanese Patent Laid-Open No. 62-270427 is provided. Here, the outflow pipe and the opening thereof are provided. Since it is heated by an external heater, the heating method is indirect, the response of the temperature control is poor, and the control accuracy is reduced.

As a temperature control device in consideration of this point, a heating electrode having a structure as shown in FIG. 9 is provided in the opening of the outflow pipe to realize direct heating of the opening (this is , JP-A-7-81944). Here, reference numeral 3 is an outflow pipe which vertically extends downward from a glass melting container (not shown) installed in a glass melting furnace, and an outflow pipe flows out by an electrode (not shown) in a predetermined vertically extending region. Direct heating is performed by energizing the tube 3, and plate-shaped electrodes 11 and 11 'having a common annular portion surrounding the opening 4 (outflow port) are attached to the tip end thereof.

The plate-shaped electrodes 11 and 11 'have heating portions 12 and 12' and electrode connecting portions 13 extending on both sides of the common annular portion.
13 ', and lead wires (not shown) are connected to the terminals (terminal portions) 14 and 14' of each electrode connecting portion. Therefore, the responsiveness of the temperature control is good, and the advantages such as high control accuracy are obtained.

[0006]

However, in the above plate-shaped electrode, the vertical thickness of the outflow pipe 3 is small,
Since it has a flat structure, it lacks rigidity against vertical bending forces. Therefore, even if the position is adjusted so that the opening of the outflow pipe 3 is positioned at a required level at room temperature with respect to the receiving mold in the state of receiving the molten glass, the outflow pipe will not be opened at the glass melting temperature. When expanded by thermal expansion, the plate-shaped electrode (which is held and fixed on the pedestal side so that its position can be adjusted) is pressed and bent within the range of its elastic deformation, and its opening is lowered. There is a risk of affecting the amount of outflow.

Therefore, under the glass outflow temperature condition, the outflow pipe 3
It is necessary to adjust the level of the opening of
There is a problem that the adjustment work is performed at a high temperature, and the level of the opening must be adjusted every time the temperature condition changes due to a difference in glass material or the like.

Therefore, even if the outflow pipe 3 thermally expands, the amount of extension in the vertical direction is absorbed by elastic deformation at the bent portion of the outflow pipe and elastic deformation at the connection portion at the bottom of the glass melting container, and the plate It is conceivable to suppress the elastic deformation on the electrode side so that the level of the opening can be adjusted at room temperature. For this purpose, it is sufficient to make the electrode large enough to increase the rigidity of the plate electrode, but the increase in mass increases the heat capacity of the plate electrode and increases the responsiveness to the sensor for temperature control. Is reduced.

The present invention has been made based on the above-mentioned circumstances, and secures high responsiveness of temperature control without increasing the mass of the plate electrode, and can withstand the load due to the thermal expansion of the glass outflow pipe. It is an object of the present invention to provide a temperature control device for a glass outflow pipe configured to secure the required rigidity and adjust the level of the opening at room temperature regardless of changes in temperature conditions due to differences in glass materials and the like.

[0010]

In order to achieve the above object, according to the present invention, when a molten glass having a required temperature is led to a mold from a glass melting container installed in a glass melting furnace through a glass outflow pipe. In order to maintain the glass temperature at the time of derivation at a required value, an electrode for conducting electric heating is arranged in a vertical region of the glass outflow pipe, and a plate electrode is attached to the opening of the glass outflow pipe. In the temperature control device for a glass outflow pipe, the plate-shaped electrode is adjusted to a required level at least with respect to the receiving mold in a state of receiving glass, and is held and fixed by the thermal expansion of the glass outflow pipe. It is characterized in that the section modulus of the electrode connecting portion is configured to increase in the vertical direction of the glass outflow pipe so as to withstand the stress applied.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) The following is a description of Embodiment 1 of the present invention.
One will be specifically described with reference to FIGS. 1 to 3. Here, reference numeral 1 is a glass melting vessel installed in a glass melting furnace (not shown), 2 is an external electric heater for heating the molten glass in the glass melting vessel 1, and 3 is made of platinum or platinum alloy It is a glass outflow pipe. In this embodiment, the glass outflow pipe 3 extends in the vertical direction, and its upper end communicates with the bottom of the glass melting furnace 1.

Reference numeral 4 is an opening (outlet) which opens at the lower end of the glass outflow pipe 3, 5 is outflow glass, and 6 is a receiving type for receiving this outflow glass 5. Also, reference numerals 7 and 8,
Reference numerals 9 and 10 denote electrodes, and a DC or AC voltage is applied between the electrodes 7 and 8 and the electrodes 9 and 10 via the glass outflow pipe 3, and the molten glass in the glass outflow pipe 3 is applied. To heat. A lead wire (not shown) as a power cable is connected to the pair of electrodes 7 and 8 and the pair of electrodes 9 and 10.

More specifically, the electrodes 9 and 10 are plate-shaped, and are provided with a common annular portion surrounding the opening 4 (outlet) at the tip of the glass outflow pipe 3, and the common annular portion. Heating parts 12 and 12 'extending to both sides of the annular part and electrode connecting parts 13,
13 ', and the above-mentioned lead wires (not shown) are connected to the terminals (terminal portions) 14 and 14' of the respective electrode connecting portions. In this embodiment, at least The receiving mold 6 in a state of receiving the outflowing glass is adjusted to a required level, and is held and fixed on a frame (not shown) so as to withstand the stress applied by the thermal expansion of the glass outflow pipe 3. In addition, the cross-section coefficient of the electrode is configured to increase in the vertical direction of the glass outflow pipe 3 (see FIGS. 2 and 3).

For example, considering the section modulus in the section a of the electrode 10 (here, in particular, the section of the terminal of the electrode connecting portion), it occurs in the section a when it receives the bending moment M about the neutral axis of the section a. The maximum normal stress σ is generally given by σ = M / Z using the section modulus Z. Therefore, the stress applied to the electrodes 9 and 10 when the glass outflow pipe 3 thermally expands changes depending on the magnitude of the section modulus. The neutral axis is a line along which the stress when the bending moment M acts becomes zero in the cross section a.

That is, when the bending moment M is the same, the larger the section modulus Z is, the smaller the stress σ is, and the plate electrodes 9 and 10 are difficult to bend. As shown in the figure, when the cross section of the plate electrode is vertically long, the horizontal neutral axis x and the vertical neutral axis y
And, the section modulus is different. For example, cross section a
If the width 1.5 mm, a vertical width and 40 mm, x-axis section modulus Zx = (1.5) × (40 ) 2/6 = 40
0, and the section modulus around the y axis Zy = (40) ×
(1.5) A ^2/6 = 15, it is advantageous to employ a longitudinal cross-sectional shape in the plate electrodes.

Of course, the portion of the glass outflow pipe 3 expanded by thermal expansion is absorbed by elastic deformation at the connection portion of the bottom of the glass melting container 1, but the rigidity is sufficient to withstand the load required for this elastic deformation. This is a requirement for the electrodes 9 and 10.

In the actual design, the plate-shaped electrodes 9 and 1 in the vertical direction when the glass outflow pipe 3 is thermally expanded.
It is necessary to set the section modulus of the electrode so that the elastic deformation amount of 0 is maintained within the tolerance level of the required level of the adjusted opening 4.

In this way, in this embodiment, high responsiveness of temperature control is ensured without increasing the mass of the plate electrodes 9 and 10, and the load due to the thermal expansion of the glass outflow pipe 3 is ensured. The rigidity that can be endured is ensured, and the level of the opening can be adjusted at room temperature regardless of changes in temperature conditions due to differences in the glass material used. (Embodiment 2) FIGS. 4 to 6 show a second embodiment of the present invention. The difference from the first embodiment is that the glass outflow pipe 3 is bent horizontally at its upper portion. This is the point where the bent portion 3A absorbs the amount of expansion due to the thermal expansion of the glass outflow pipe 3, and an electrode 15 is added to the electrodes 7 and 8 which are energized to the glass outflow pipe 3. The voltage application area is divided into two zones. Since other configurations are not different from those of the first embodiment, the same components are designated by the same reference numerals and the description thereof will be omitted.

Here, too, the plate electrodes 9 and 10 are designed to withstand the stress applied by the thermal expansion of the glass outflow pipe 3,
The cross-sectional modulus of the electrode is configured to be large in the vertical direction of the glass outflow pipe 3. Therefore, also in this embodiment, a high responsiveness of temperature control is ensured without increasing the mass of the plate-shaped electrodes 9 and 10, and moreover, a rigidity capable of withstanding a load due to thermal expansion of the glass outflow pipe 3 is secured. However, it is possible to adjust the level of the opening at room temperature regardless of changes in temperature conditions due to differences in the glass material used. (Third Embodiment) FIGS. 7 and 8 show a third embodiment of the present invention. The difference from the first embodiment is that the glass outflow pipe 3 is bent horizontally at the upper portion thereof. This is the point where the bent portion 3A absorbs the amount of expansion due to the thermal expansion of the glass outflow pipe 3, and an electrode 15 is added to the electrodes 7 and 8 which are energized to the glass outflow pipe 3. The voltage application area is divided into two zones. Further, the difference from the second embodiment is that the plate-shaped electrode 9,
The mounting direction of 10 is at a point where the phase is shifted by 90 degrees in a plan view. Since other configurations are not different from those of the first embodiment, the same components are designated by the same reference numerals and the description thereof will be omitted.

Here, too, the plate electrodes 9 and 10 are designed to withstand the stress applied by the thermal expansion of the glass outflow pipe 3,
The cross-sectional modulus of the electrode is configured to be large in the vertical direction of the glass outflow pipe 3. Therefore, also in this embodiment, a high responsiveness of temperature control is ensured without increasing the mass of the plate-shaped electrodes 9 and 10, and moreover, a rigidity capable of withstanding a load due to thermal expansion of the glass outflow pipe 3 is secured. However, it is possible to adjust the level of the opening at room temperature regardless of changes in temperature conditions due to differences in the glass material used.

[0021]

EXAMPLE In order to clarify the constitution of the present invention and its function and effect, a comparative example in which the conventional plate electrode shown in FIG. 9 has been actually adopted (see FIGS. 10 and 11). At the same time, the efficacy of the plate electrode of the present invention will be specifically and numerically disclosed below. (Embodiment 1) As Embodiment 1 of the present invention, FIGS.
In the configuration of the embodiment shown in FIG.
Inner diameter = 7 mm, outer diameter = 10 mm, full length (length from the connection point at the bottom of the glass melting container 1 to the opening (outlet) 4)
= 350 mm, the distance between the electrodes 7 and 8 = 200 mm,
The cross sections of the heater parts 12 and 12 'have a width of 7 mm and a length of 7 mm, and the terminals 14 and 14' of the electrode connection part have a width of 1.5 mm and a length of 40 mm. Also,
SK12 (BaO, B ₂ O ₃ , Si
O ₂ as a main component), the level of the opening 4 with respect to the receiving mold 6 is adjusted at room temperature, and in that state,
The plate-shaped electrodes 9 and 10 are held and fixed on a mount (not shown).
The distance between the opening 4 and the upper surface of the receiving die 6 in the state of receiving the outflowing glass is 10.0 ± 0.1 mm at room temperature.

When the glass flows out, the electrodes 7 and 8 are used.
By changing the outflow pipe temperature between 800 ~ 1000 ℃,
The glass outflow rate was changed to 2 to 30 g / min. At this time, the temperature of the glass melting container 1 is maintained at 1100 ° C., and the temperature at the common annular portion of the plate electrodes 9 and 10 is maintained at 1160 ° C.

When the temperature of the outflow pipe between the electrodes 7 and 8 is set to 800 to 1000 ° C., the length of the outflow pipe 3 is extended by 1.7 to 2.2 mm as compared with the case of normal temperature. However, this is in the form of being absorbed by the elastic dent at the connection point at the bottom of the glass melting furnace 1 and does not cause damage to the deformation point, and the stress corresponding to this load causes the plate-shaped electrode 9, 1
However, since the plate-shaped electrodes 9 and 10 have a large section modulus, the distance between the opening 4 and the upper surface of the receiving die 6 is substantially zero. There is no change and it is within the tolerance. Therefore, if the level of the opening 4 is adjusted at room temperature, readjustment at high temperature becomes unnecessary.

Instead of the above-mentioned plate-shaped electrodes 9 and 10, the conventional plate-shaped electrodes 11 and 11 'shown in FIG. 9 (the cross-section a of the terminals 14 and 14' of the electrical connection portion has a horizontal width and a vertical width). A value opposite to that of the plate electrodes 9 and 10 of the present invention, that is, width = 40 m
m, vertical width = 1.5 mm) and the same conditions as above are applied, the temperature of the outflow pipe is changed from room temperature to 800
When the temperature changes to ˜1000 ° C., the plate electrodes 11, 1
1'is pressed and bent downward near the electrode connection portions 13 and 13 'due to the expansion accompanying the thermal expansion of the glass outflow pipe 3, and the distance between the opening 4 of the glass outflow pipe and the upper surface of the receiving mold 6 becomes It became shorter than the set value of 10.0 ± 0.1 mm. As a result, under such high temperature conditions,
Again, it became necessary to adjust the position level of the opening 4. (Embodiment 2) In this embodiment, with respect to the cross section a of the terminals 14 and 14 'of the electrode connecting portions of the plate electrodes 9 and 10, the lateral width =
2.3 mm, vertical width = 26 mm, and other conditions were the same as in Example 1. When the section modulus in this case is calculated, the section modulus around the horizontal x-axis is Zx = (2.3) ×
(26) 2/6 = 259, and the section modulus around the vertical y axis is Zy = (26) × (2.3) 2/6 = 23, which is a large section modulus.

As a result, as in the first embodiment, since the plate-shaped electrodes 9 and 10 have large section modulus, there is substantially no change in the distance between the opening 4 and the upper surface of the receiving die 6, and the tolerance is small. Is within the range of. Therefore, if the level of the opening 4 is adjusted at room temperature, readjustment at high temperature becomes unnecessary.

Instead of the above-mentioned plate-shaped electrodes 9 and 10, the conventional plate-shaped electrodes 11 and 11 'shown in FIG. 9 (the cross-section a of the terminals 14 and 14' of the electrode connecting portion have a horizontal width and a vertical width). A value opposite to that of the plate electrodes 9 and 10 of the present invention, that is, width = 26 m
m, vertical width = 2.3 mm) and the same conditions as above are applied, the temperature of the outflow pipe is changed from room temperature to 800
When the temperature changes to ˜1000 ° C., the plate electrodes 11, 1
1'is pressed and bent downward near the electrode connection portions 13 and 13 'due to the expansion accompanying the thermal expansion of the glass outflow pipe 3, and the distance between the opening 4 of the glass outflow pipe and the upper surface of the receiving mold 6 becomes It became shorter than the set value of 10.0 ± 0.1 mm. As a result, under such high temperature conditions,
Again, it became necessary to adjust the position level of the opening 4. (Embodiment 3) As Embodiment 3 of the present invention, FIGS.
In the configuration of the embodiment shown in FIG.
Inner diameter = 6 mm, outer diameter = 8.5 mm, full length (length from the connection point of the glass melting container 1 to the opening (outlet) 4) =
600 mm, the distance between the electrodes 7, 15 and the electrodes 15, 8 = 300 mm and 200 mm, and the heater unit 12,
The cross section of 12 'has a horizontal width of 6 mm and a vertical width of 6 mm, and the cross section of the terminals 14, 14' of the electrode connecting portion has a horizontal width of 2 mm.
The vertical width is 30 mm. In addition, for the molten glass material, L
aK12 (glass containing B ₂ O ₃ and La ₂ O ₃ as main components) is used, and the level of the opening 4 with respect to the receiving mold 6 is adjusted at room temperature. It is held and fixed to (not shown). While receiving the spilled glass,
The space between the opening 4 and the upper surface of the receiving mold 6 is 7.
It is set to 0 ± 0.1 mm.

When the glass flows out, the electrodes 7 and 8 are used.
The glass outflow rate was changed to 0.5 to 40 g / min by changing the outflow pipe temperature to 700 to 950 ° C. At this time, the temperature of the glass melting container 1 is maintained at 1000 ° C., and the temperature at the common annular portion of the plate electrodes 9, 10 is maintained at 1080 ° C.

When the temperature of the outflow pipe between the electrodes 7 and 15 and between the electrodes 15 and 8 is set to 700 to 950 ° C., the length of the outflow pipe 3 is 1 toward the right side of FIG. ~ 1.
About 4 mm, or about 2.4 to 3.3 mm vertically downward,
It has been stretched, but this is the bent portion 3A of the glass outflow pipe 3.
In this case, the shape is absorbed by elastic bending, and the deformed portion is not damaged, and the stress corresponding to this load is applied to the plate-shaped electrodes 9 and 10 to cause a slight elastic deformation. However, since the plate-shaped electrodes 9 and 10 have a large section modulus, there is substantially no change in the distance between the opening 4 and the upper surface of the receiving die 6, which is within the allowable error range. Therefore, if the level of the opening 4 is adjusted at room temperature, readjustment at high temperature becomes unnecessary.

In exchange for this, the plate electrodes 9 and 10 described above are used.
Instead of the conventional plate-shaped electrodes 11 and 11 'shown in FIG.
(For the cross section a of the terminals 14 and 14 'of the electrode connecting portion,
The width and height are opposite to those of the plate electrodes 9 and 10 of the present invention, that is, the width is 30 mm and the height is 2 mm. In case (see Fig. 10 and Fig. 11), the temperature of the outflow pipe is changed from room temperature to 7
When the temperature changes from 00 to 950 ° C, the plate electrodes 11 and 1
1'is pressed and bent downward near the electrode connection portions 13 and 13 'due to the expansion accompanying the thermal expansion of the glass outflow pipe 3, and the distance between the opening 4 of the glass outflow pipe and the upper surface of the receiving mold 6 becomes It became shorter than the set value of 7.0 ± 0.1 mm. As a result, it becomes necessary to adjust the position level of the opening 4 again under such a high temperature condition. (Fourth Embodiment) As yet another embodiment, when the same concrete numerical values as in the third embodiment are applied in the embodiment shown in FIGS. 7 and 8, the result is completely different from that in the third embodiment. It was similar.

[0030]

The present invention has been described in detail above, and when a molten glass having a required temperature is discharged from a glass melting vessel installed in a glass melting furnace to a mold through a glass outflow tube, the glass outflow tube is used. A glass outflow tube is provided with an electrode for electrically heating in a vertically extending partial area of the glass outflow tube, and a plate electrode is attached to the opening of the glass outflow tube to maintain the glass temperature at the time of derivation at a required value. In the temperature control device, the plate electrode is adjusted to a required level at least with respect to the receiving mold in a state of receiving glass, and is held and fixed, and the stress applied by the thermal expansion of the glass outflow pipe. In order to withstand the above, the cross-sectional modulus of the electrode is configured to increase in the vertical direction of the glass outflow pipe.

Therefore, a high responsiveness of temperature control is ensured without increasing the mass of the plate-like electrode, and a rigidity capable of withstanding the load due to the thermal expansion of the glass outflow pipe is ensured. An effect that the level of the opening can be adjusted at room temperature regardless of changes in temperature conditions can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a temperature control device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part, similarly.

FIG. 3 is likewise a view showing a section a of FIG.

FIG. 4 is a schematic front view showing a second embodiment of the present invention.

FIG. 5 is likewise a schematic side view.

FIG. 6 is likewise a view showing a section a of FIG.

FIG. 7 is a schematic front view showing still another embodiment of the present invention.

FIG. 8 is likewise a schematic side view.

FIG. 9 is a schematic perspective view showing a main part of a conventional example.

FIG. 10 is likewise a schematic front view.

FIG. 11 is likewise a schematic side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass melting container 2 Heater 3 Glass outflow pipe 3A Bent part 4 Opening 5 Outflow glass 6 Receiving type 7, 8, 15 Electrode 9, 10 Plate electrode 11, 11 'Plate electrode 12, 12' Heater part 13, 13 'Electrode connection 14, 14' Terminal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isamu Isamu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. When a molten glass having a required temperature is discharged from a glass melting container installed in a glass melting furnace into a receiving mold through a glass outflow pipe, electric heating is performed on a partial region extending in the vertical direction of the glass outflow pipe. With the arrangement of electrodes, the plate-shaped electrode is attached to the opening of the glass outflow pipe, and in the temperature control device for the glass outflow pipe, which is configured to maintain the glass temperature at the time of derivation at a required value, the plate-shaped electrode is At least, with respect to the receiving mold in the state of receiving the glass, it is adjusted to a required level, is held and fixed, and the sectional modulus of the electrode is so as to withstand the stress applied by the thermal expansion of the glass outflow pipe, A glass outflow pipe temperature control device, characterized in that the glass outflow pipe has a shape that increases in the vertical direction. 2. The cross-section coefficient of the electrode is adjusted so that the elastic deformation amount of the plate electrode in the vertical direction during thermal expansion of the glass outflow pipe is maintained within the adjusted tolerance level of the required level. The temperature control device for a glass outflow pipe according to claim 1, wherein the temperature control device is set.