JPH107421A - Stirring method and stirrer for hot melt - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent the generation of entrained bubbles around the rotating shaft when stirring and homogenizing a high-temperature melt. A stirring device is provided with stirring blades around a rotating shaft. Among the three stirring blades, the stirring blade 31 located at the uppermost stage has a rotating shaft 3
In the vicinity of 0, there is an inclined surface 31a inclined downward in the rotation direction indicated by the solid line arrow in the figure, and on the outside thereof, an inclined surface 31b inclined upward in the rotational direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirring method and a stirring apparatus for stirring and homogenizing a high-temperature molten material such as a molten glass.

[0002]

2. Description of the Related Art Generally, a glass melting furnace is provided with an apparatus for stirring a molten glass in order to homogenize the molten glass. For example, in a glass melting furnace for producing glass for TV bulbs, a stirrer is installed upstream of a gob cutting device in a forehearth portion.

[0003] Such a stirring device has two functions for homogenizing the molten glass. One is the function of rotating the stirring blade around the rotation axis to disturb the flow of the molten glass and homogenize it. The other function is to generate an upward or downward flow in the molten glass, lengthen the flow path, and homogenize the molten glass.

In order to provide an upward or downward flow to the molten glass, the stirring blade is generally inclined at a certain angle in the direction of rotation. When the stirring blade is inclined downward in the rotation direction, the rotation imparts an upward flow to the molten glass, and when the stirring blade is inclined upward in the rotation direction, the molten glass is inclined by the rotation. Is given a downward flow.

FIG. 3 is a perspective view showing a stirring blade used in such a stirring device. A stirring blade 34 is mounted around the rotation axis 30. The rotation direction of the rotation shaft 30 is the direction indicated by the solid arrow in the figure. The stirring blade 34 is
It has an inclined surface 34a inclined upward in the rotation direction. When the stirring blade is rotated in the molten glass, a downward flow indicated by a dotted arrow is applied to the molten glass along the inclined surface 34a.

FIG. 5 is a plan view of the entire stirring device using such stirring blades as viewed from above. Stirring blades 34, 35 and 36 are attached around the rotation axis 30 in order from the top, and the stirring blades 35 and 36 are the stirring blades 3 shown in FIG.
Same as 4. The stirring blades next to each other are approximately 45
° It is attached to the rotating shaft 30 in a twisted state.
When this stirring blade is rotated in the direction of the arrow in the molten glass, a downward flow is applied to the molten glass along the inclined surfaces 34a, 35a, 36a.

[0007]

However, there is a problem that, when a downward flow is applied to the molten glass by the agitating device, bubbles are likely to be entrained with this flow. When bubbles are entrained, the molten glass is cooled and solidified to significantly lower the quality of the final glass product, which may lead to a reduction in production yield.

[0008] Accordingly, an object of the present invention is to provide a stirring method and a stirring device for suppressing the occurrence of entrainment of bubbles when stirring and homogenizing a high-temperature molten material such as molten glass.

[0009]

SUMMARY OF THE INVENTION The present invention is a method for agitating and homogenizing a high-temperature melt, which has a blade surface provided around a rotation axis and inclined in a rotation direction. By rotating one or more stirring blades, the flow of the high-temperature melt is deflected upward in the vicinity of the rotation axis, and the flow of the high-temperature melt is deflected downward outside the high-temperature melt. Is provided.

The present invention also provides a stirring device for stirring and homogenizing a high-temperature melt, wherein the stirring device has a rotating shaft, and a blade surface provided around the rotating shaft and inclined in a rotating direction.
And at least one stirring blade, wherein the blade surface has an inclination to deflect the flow of the high-temperature melt upward near the rotation axis, and has an inclination to deflect the flow of the high-temperature melt downward outside the rotation surface. An apparatus for stirring a high-temperature melt is provided.

In the present invention, by employing the above-described structure, even when a downward flow is applied to the high-temperature molten material, bubbles are less likely to be entrained by the flow.

In a preferred embodiment of the present invention,
A plurality of stirring blades are provided around the rotation axis, and the blade surface of the uppermost stirring blade has an inclination to deflect the flow of the high-temperature melt upward near the rotation axis, and outside thereof, It is characterized in that it has a slope that deflects the flow of the hot melt downward, and the blade surface of the remaining stirring blades has a slope that deflects the flow of the hot melt downward.

[0013] In this aspect, it is easy to apply a downward flow to the high-temperature melt near the rotation axis and to apply a downward flow to the high-temperature melt as a whole.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a stirring method and an apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 2 is a perspective view showing one embodiment of a stirring blade of the stirring device of the present invention. Rotary axis 3
Around the zero, a stirring blade 31 is attached.

The direction of rotation of the rotary shaft 30 is the direction indicated by the solid arrow in the figure. In the vicinity of the rotating shaft 30, the stirring blade 31 has an inclined surface 31 that is inclined downward in the rotation direction.
a, and on the outside thereof, an inclined surface 31b inclined upward in the rotation direction. Therefore, when this stirring blade is rotated in the high-temperature melt, an upward flow indicated by a dotted arrow is given to the high-temperature melt along the inclined surface 31a in the vicinity of the rotating shaft 30, and outside the rotary shaft 30 outside the rotary shaft 30. A downward flow indicated by a dotted arrow is applied along the inclined surface 31b.

FIG. 4 is a plan view from above of a stirring device 40 using such a stirring blade. Agitating blades 31, 32, and 33 are mounted around the rotating shaft 30 in order from the top, and the agitating blades 32 and 33 are the same as the conventionally used agitating blades. The stirring blades next to each other
They are attached to the rotating shaft 30 in a state where they are twisted by about 45 degrees.

When the stirring blade is rotated in the direction of the arrow in the drawing in the molten glass, a downward flow is imparted to the high-temperature melt as a whole, and the rotation axis of the stirring device is located near the surface of the high-temperature melt. In the vicinity, an upward flow will be provided. Thus, according to the stirring device of the present invention,
While a downward flow can be imparted to the hot melt, bubbles are less likely to be entrained due to the downward flow.

The angle of inclination of the inclined surface of each stirring blade may be appropriately adjusted according to the rotation speed of the stirring blade.
It can be adjusted between about 20 and 90 degrees with respect to the horizontal. In addition, the twist angle between the upper and lower adjacent stirring blades can also be appropriately adjusted depending on how much flow is applied and the number of blades in each stage, but in general,
It can be adjusted between 35 and 55 degrees. The width of the inclined surface 31a inclined downward in the rotation direction may be appropriately adjusted according to the viscosity of the high-temperature melt and the rotation speed of the stirring blade.

In particular, in the present embodiment, only the uppermost stirring blade is provided with an inclined surface which is inclined downward in the direction of rotation to impart an upward flow to the high-temperature melt.
By appropriately adjusting the width, all the stirring blades can be provided with inclined surfaces inclined downward in the rotation direction.

In this embodiment, the angle of inclination is substantially constant within one inclined surface of the stirring blade, but the angle of inclination may be varied within one inclined surface. The inclination angle increases as it approaches the periphery of the stirring blade,
Conversely, those that become smaller can also be adopted.

Further, the stirring blade may be formed as a separate part from the rotating shaft, and may be attached to the rotating shaft later, or may be formed integrally with the rotating shaft.

The material of the stirring blade is not particularly limited as long as it is a material having resistance to a high-temperature melt. If the molten glass is stirred and homogenized, heat-resistant platinum,
Alternatively, it is preferable to use a platinum rhodium alloy. Further, in order to improve heat resistance, a material in which molybdenum having a high melting point is used as a core material, this molybdenum core material is coated with alumina, and platinum or a platinum-rhodium alloy is coated thereon may be used.

FIG. 1 is a plan view showing a side port type glass melting tank kiln using the stirring apparatus of the present invention. The glass melting tank kiln 1 shown in FIG.
0, cooling tank 12, and foreheart part 14, 14, ...
・ It is composed of A dock house 16 is formed on the right side of the melting tank 10 in the drawing.
0 is supplied with a glass raw material. The glass raw material supplied to the melting tank 10 is melted by a burner formed by hot air from the heat storage chamber 18 and oil sprayed from a combustion port (port) to become a high-temperature molten glass G.

The molten glass G is supplied from the melting tank 10 through the throat 22 to the cooling tank 12, and is supplied to the cooling tank 1.
After cooling to a predetermined temperature in 2 and removing bubbles contained in the molten glass G, the forehearth portion 1
4 is supplied. A stirrer 40 shown in FIG. 1 is installed in the forehearth section 14 to stir the molten glass G,
Perform homogenization. If necessary, the same stirrer may be used in combination with one that imparts an upward flow to the molten glass G.

Next, the homogenized molten glass G is cut out as a gob by a gob cutting device 15 provided at the tip of the forehearth portion 14, and is subjected to a forming process in a subsequent forming step to be commercialized.

Although FIG. 1 illustrates the case where the stirring apparatus of the present invention is used in a side port type glass melting tank kiln, it can be applied to other glass melting furnaces. further,
The present invention can be applied to a high-temperature molten material other than the molten glass, for example, a molten metal.

[0027]

According to the present invention, the flow of the high-temperature melt can be deflected upward in the vicinity of the rotation axis of the stirring device, so that when the high-temperature melt is stirred and homogenized, it is wound around the rotation axis. The generation of bubbles can be prevented, which can contribute to improving the quality and yield of glass products.

Further, a plurality of stirring blades are provided around the rotation axis, and the blade surface of the uppermost stirring blade has an inclination near the rotation axis to deflect the flow of the high-temperature melt upward, If the blade surfaces of the remaining stirring blades are inclined so as to deflect the flow of the high-temperature melt downward, a downward flow is imparted to the high-temperature melt in the vicinity of the rotation axis, and as a whole, It is easy to apply a downward flow.

[Brief description of the drawings]

FIG. 1 is a plan view of a tank furnace for melting glass.

FIG. 2 is a perspective view showing a stirring blade according to one embodiment of the present invention.

FIG. 3 is a perspective view showing a conventional stirring blade.

FIG. 4 is a plan view showing a stirring device according to one embodiment of the present invention.

FIG. 5 is a plan view showing a conventional stirring device.

[Explanation of symbols]

 1: tank kiln for melting glass 10: melting tank 12: cooling tank 14: forehearth section 22: throat 30: rotating shaft 31 to 36: stirring blade 40: stirring device

Claims (4)

[Claims] 1. A method for agitating and homogenizing a high-temperature melt, comprising: rotating one or more agitating blades provided around a rotating shaft and having a blade surface inclined toward a rotating direction. The method according to claim 1, wherein the flow of the high-temperature melt is deflected upward near the rotation axis, and the flow of the high-temperature melt is deflected downward outside the rotation axis. 2. A stirrer for stirring and homogenizing a high-temperature melt, comprising: a rotating shaft; and at least one wing surface provided around the rotating shaft and inclined in a rotating direction. The blade surface has an inclination to deflect the flow of the high-temperature melt upward near the rotation axis, and has an inclination to deflect the flow of the high-temperature melt downward outside the rotation surface. A stirring device for a high-temperature melt. 3. A plurality of stirring blades are provided around the rotation axis, and the blade surface of the uppermost stirring blade has an inclination near the rotation axis to deflect the flow of the high-temperature melt upward. The outside of the agitator has a slope for deflecting the flow of the hot melt downward, and the remaining stirring blades have a slope for deflecting the flow of the hot melt downward. A stirrer for the high-temperature melt according to the above. 4. The inclination for deflecting the flow of the high-temperature melt upward is inclined downward toward the rotation direction of the blade, and the inclination for deflecting the flow of the high-temperature melt downward is the rotation direction of the blade. The high-temperature melt stirring device according to claim 2 or 3, wherein the high-temperature melt stirring device is inclined upward toward.