JPH01164737A - Method for feeding molten glass - Google Patents

Abstract

PURPOSE:To quantitatively feed molten glass at a constant rate by using a furnace having a sectorial or nearly sectorial vertical section and an outlet at the position of the pivot. CONSTITUTION:A sectorial or nearly sectorial vertical section is provided to the molten glass 2 storage part 3 of a furnace 1 having heating elements 4a arranged at the upper part of the furnace and heating elements 4b, 4c embedded in the bottom and side walls and an outlet 5 having a platinum sheet 6 stuck to the bottom is formed at the position of the pivot of the sector. Molten glass 2 having 3.0-4.0 logdelta viscosity is put in the furnace 1 and the furnace 1 is tilted on the molten glass overflow position 5a of the outlet 5 as the central axis at 1-20 deg./min rate to allow the molten glass 2 to flow out at a constant rate.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for supplying a glass melt, and in particular to a method for supplying a glass melt melted in a batch manner using a crucible at a constant supply rate. Regarding possible supply methods.

[Prior art] When molding glass melted in batches using a crucible (for example, making plates), fluctuations in the supply rate of the glass melt from the crucible have a negative effect on the quality and yield of the resulting product. . For this reason, it is necessary to feed the glass melt at a constant feed rate.

Conventionally, the methods for supplying glass melted in a batch manner using a crucible to molding processes, etc. are: ■ A method in which the crucible is tilted to flow out the glass melt; ■ A method in which the glass melt is flowed out through a nozzle installed at the bottom of the crucible. A method is used within the shell.

[Problems to be Solved by the Invention] In the method (2) above, since the shape of the crucible is cylindrical and the temperature of the glass melt changes during pouring, the glass melt is supplied at a constant rate. It is difficult to supply such materials. In addition, in method The liquid level of
Again, it is difficult to feed the glass melt at a constant feed rate, since the outflow rate of the glass melt decreases.

In this way, in the batch melting method, it is difficult to supply glass melt at a constant supply rate with conventional methods, so when molding molten glass by the batch melting method, product quality and yield etc. A fully satisfactory result could not be obtained.

[Means for Solving the Problems] The present invention provides a method in which a glass melt can be quantitatively supplied at a constant supply rate in a batch melting method. The glass melt supply method of the present invention includes a furnace in which the vertical cross-sectional shape of the glass melt storage part is fan-shaped or a fan-like shape, and the glass melt has an outlet at a key position of the fan shape. It is characterized by allowing the glass melt to flow out by tilting the glass with a rotational center.

Hereinafter, the tree invention will be explained in detail with reference to the drawings.

1 and 2 are schematic diagrams showing an example of a glass melt supply device suitable for carrying out the invention, in which FIG. 1 is a longitudinal sectional view, and FIG. 2 is taken along the line II-II in FIG. 1. FIG.

As shown in the figure, in the glass melt supply device, the vertical cross-sectional shape of the storage portion 3 for the glass melt 2 in the furnace 1 of the main body is approximately fan-shaped, and the glass melt supply device has an outlet 5 for the glass melt at a key position of the fan shape. In order to keep the temperature of the glass melt 2 uniform and constant, a heating element 4a is provided above the glass melt 2, and a heat generating element 4a is provided below and on the sides of the storage section 3 of the main body 1. The bodies 4b and 4c are buried. Outlet part 5 that gets cold easily
A platinum plate 6 is attached to the bottom surface of the plate, and the plate is configured to be heated with electricity.

In the present invention, using such a furnace 1, when the glass melt 2 flows out from the furnace 1 and is supplied to a molding process, etc., the glass melt at the outlet part 5 of the furnace 1, more precisely, the glass melt at the outlet part 5 is By tilting the furnace 1 with the overflow position 5a as the central axis of rotation, the glass melt flows out at a constant speed.

In this case, the tilting speed is appropriately determined depending on the viscosity and flow rate of the glass melt to be flowed out, the scale of the furnace, the shape of the fan-shaped cross section, and the like. Generally, the tilting speed of the furnace 1 is 1 to 20 degrees/
min is determined depending on each setting condition, particularly in the range of 5 to 10 degrees/min.

The tilting speed of the furnace may be kept at a constant speed while the glass melt flows out, but in reality, the glass melt has a high viscosity, so a constant tilting speed tends to cause fluctuations in the flow rate.
In many cases, 40 to 60% of the furnace capacity can be supplied quantitatively at a constant flow rate. In such a case, the uniformity of the flow rate of the glass melt can be improved by appropriately controlling the tilting speed of the furnace using a computer or the like. That is, for example, at the beginning of the tilting, the tilting is performed at a relatively high tilting speed,
It is preferable to gradually reduce the speed thereafter, and then increase the tilting speed again at the end of the tilting (outflow). By adjusting the tilting speed in this way, it is possible to quantitatively supply 80% or more of the furnace capacity.

In carrying out the present invention, if the temperature of the glass melt 2 in Class 1 is non-uniform, viscosity unevenness may occur, making it difficult to flow out at a constant speed. For this reason, as shown in FIGS. 1 and 2, by installing heating elements 4a, 4b, and 4c in the storage section 3 of the furnace 1 or near the storage section 3,
It is preferable to keep the temperature of the glass melt 2 uniform and constant.

Furthermore, since the temperature of the glass melt 2 tends to be low and the viscosity to be high at the outlet 5 of the furnace 1, a platinum plate 6 or the like is provided as shown in the figure and electricity is applied to this to heat the outlet. is preferable.

In the present invention, the temperature of the glass melt to be discharged varies depending on the glass composition, etc., but is generally kept uniform and constant at a temperature such that the viscosity of the glass melt is approximately 3.0 to 4.0. It is preferable to keep it at

[Function] In the present invention, since a furnace having a vertical cross-sectional shape, a fan shape, or a shape similar to a fan shape and having an outlet at a key position of the fan shape is used, the amount of molten glass in the furnace fluctuates. Also, the glass melt can flow out at a constant flow rate and be supplied quantitatively.

Furthermore, since the center of rotation of the furnace is set at the furnace outlet, it is possible to supply the glass melt at a fixed position.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

Example 1 Using the apparatus shown in FIGS. 1 and 2, the furnace 1 was tilted about the overflow position 5a of the outlet section 5 as the center of rotation, and the glass melt 2 was caused to flow out. Incidentally, the tilting speed of the furnace 1 was kept constant as shown in FIG. 3A.

The glass used is a float composition glass, and the heating element 4
By energizing a, 4b, 4c and the platinum plate 6, 1
It was maintained at 100° C. and JZog η = 3.5. The measurement results of the outflow velocity in this case are shown in FIG. 4, N011.

As is clear from FIG. 4, in this example, it was possible to quantitatively supply approximately 50% of the furnace capacity of the glass melt at a constant outflow rate.

Example 2 Glass melt was poured out in the same manner as in Example 1, except that the furnace tilting speed was adjusted as shown in B in Figure 3 in order to improve the stability of the outflow rate. It was measured. The results are shown in Figure 4, No. 12.

As is clear from FIG. 4, in this example, it was possible to quantitatively supply approximately 80% of the furnace capacity of the glass melt at a constant outflow rate.

Example 3 Alumino-silicate glass was used and 1465
An experiment was conducted in the same manner as in Example 1, except that the outflow was performed while maintaining the temperature at (°C, j2ogy) = 3.2, and the outflow rate was measured. The results are shown in FIG. 4, No. 013.

As is clear from FIG. 4, in this example, it was possible to quantitatively supply approximately 50% of the furnace capacity of the glass melt at a constant outflow rate.

Example 4 The furnace tilting speed was adjusted as shown in Figure 3B.
The alumino-silicate glass was drained in the same manner as in Example 3, and the flow rate was measured. The results are shown in Figure 4, No.
4.

As is clear from FIG. 4, in this example, it was possible to quantitatively supply approximately 85% of the furnace capacity of the glass melt at a constant outflow rate.

[Effects of the Invention] As detailed above, according to the method for supplying glass melt of the present invention, it is possible to quantitatively supply glass melt at a constant rate in a batch melting method, which was difficult with conventional methods. is possible. Furthermore, by appropriately adjusting the furnace tilting speed, it is also possible to quantitatively supply 80% or more of the furnace capacity of the glass melt at a constant rate.

Therefore, by adopting the method of the present invention, it becomes possible to easily and quantitatively supply the glass melt at a constant rate, thereby enabling stable molding in the molding process, improving the quality of molded products and improving the yield. can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing an embodiment of a glass melt quantitative supply device suitable for implementing the present invention, FIG. 2 is a cross-sectional view taken along the line n-Ii in FIG. 1, and FIG. FIG. 4 is a graph showing the setting conditions of the furnace tilting speed in the example, and FIG. 4 is a graph showing the measurement results of the flow rate of the glass melt in the example. 1... Glass melt supply device body (furnace), 2... Glass melt, 4a, 4b, 4c=-heating element, 6... Platinum plate. ♀ Lr＞O

Claims (3)

[Claims] (1) A furnace in which the vertical cross-sectional shape of the glass melt storage part is fan-shaped or a fan-like shape and has an outlet for the glass melt at a key position of the fan shape is tilted about the outlet. A method for supplying a glass melt, characterized by causing the glass melt to flow out. (2) Claim 1, in which the temperature of the glass melt is maintained uniformly and the glass melt flows out by installing a heating element in or near the storage portion of the furnace for the glass melt. supply method. (3) By programmatically controlling the tilting speed of the furnace,
The supply method according to claim 1 or 2, wherein 80% or more of the glass melt of the furnace capacity is caused to flow out at a constant flow rate.