JPH0354117Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a stirrer for molten glass, and particularly to a stirrer for molten glass with excellent stirring efficiency.

[Prior Art] In a glass melting apparatus, a molten glass stirrer used for homogeneous stirring of the glass melt has conventionally been made by simply attaching plate blades to a rotating rod. Although it was possible to perform agitation in the vertical direction, it was not possible to perform sufficient agitation in the vertical direction. On the other hand, a system in which a spiral blade is attached to a rotating rod has been proposed to enable vertical stirring.

[Problems to be solved by the invention] In conventional stirrers, even if the stirrer is equipped with spiral blades, the stirring force at the bottom of the stirring tank, especially the lower part of the stirrer rotation shaft, is not absorbed by other parts of the stirring tank. It was difficult to make this part homogeneous. For this reason, especially in the case of glass melt containing volatile components, the melt near the surface whose composition has changed is drawn into the interior by the stirrer and becomes retained at the bottom of the stirring tank where the stirring force is weak. It was difficult to make this part a homogeneous composition.

Conventionally, as a countermeasure against this problem, the stirring power at the bottom has been increased by increasing the rotational speed of the stirrer. However, platinum and platinum alloys that do not contaminate the glass melt are generally used as stirrer materials, and because these have low high-temperature strength, even at high temperatures of 1500 to 1550°C, ogn = 2.5 to 3.0 or higher. Glass melt having high viscosity cannot be stirred at high rotational speed. For this reason, in the past, it has been extremely difficult to uniformly prepare such a high viscosity glass melt.

[Means for Solving the Problems] The present invention solves the above-mentioned conventional problems and provides a stirrer for molten glass that can uniformly stir even at a low rotation speed and has extremely high stirring efficiency. It is something.

The stirrer for molten glass of the present invention includes a rotating shaft installed in the vertical direction, and first and second stages arranged on the rotating shaft in at least three stages from the top to the bottom.
and a third plate blade.

The upper first plate blade is installed at an inclination so as to have a positive or negative elevation angle with respect to the rotation direction, and the middle second plate blade is installed so that its plate surface is in the axial direction of the rotation axis. It is installed in And the third lower
The blades are installed so as to be inclined with respect to the direction of rotation so as to have an angle of elevation opposite to that of the first blade.

[Function] The stirrer for molten glass of the present invention is installed so that the upper first plate blade has a positive or negative elevation angle with respect to the rotation direction of the rotation axis. By rotating in the direction of
The glass melt on the surface of the stirring tank can be drawn downward into the interior.

On the other hand, since the lower third plate blade is installed at an angle with respect to the rotation direction so as to have an elevation angle opposite to that of the first plate blade, rotation of the rotation axis in the desired direction causes the inner bottom of the stirring tank to The glass melt can be scraped upward and into the interior.

In addition, the inside of the stirring tank is sufficiently stirred by the medium plate blade installed so that the plate surface is in the axial direction of the rotating shaft.

Therefore, according to the stirrer for molten glass of the present invention, the glass melt can be thoroughly stirred from the surface to the bottom, and the glass melt can be efficiently stirred to create a uniform glass without increasing the rotation speed. A melt can be obtained.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

Fig. 1 is a perspective view showing a stirrer for molten glass according to an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view of a stirring tank using the stirrer for molten glass shown in Fig. FIG. 4 is an end view of a cross section taken along the line of FIG.

As shown in the figure, the stirrer 1 for molten glass of the present invention includes a rotating shaft 2 installed in the vertical direction, and first plate blades 3 arranged on the rotating shaft 2 in three stages, upper, middle, and lower. It has a second plate blade 4 and a third plate blade 5. The first plate blade 3 is installed so as to be inclined to have an elevation angle θ ₁ with respect to the rotation direction of the rotation shaft 2 . The second plate blade 4 is installed so that its plate surface is in the axial direction of the rotating shaft 2. The third blade 5 is installed so as to be inclined with respect to the rotational direction of the rotating shaft 2 so as to have an elevation angle θ ₂ opposite to that of the first blade 3 .

In the embodiment shown in FIGS. 1 to 4, the second
Two blades 4 (namely 4a and 4b) are provided, each of which extends tangentially from the circumferential surface of the rotating shaft 2 and is arranged symmetrically with respect to the axis of the rotating shaft. In addition, the first and third plate blades 3,
5 are provided one each, and the first plate blade is installed above one of the second plate blades 4a so that its lower edge side is the side to which the second plate blade 4a is attached. The third plate blade 5 is installed below the other second plate blade 4b so that its upper edge side is the side to which the second plate blade 4b is attached. In addition, in FIG. 2, 6 is glass melt, 7
is a stirring tank.

In such a stirrer 1, in order to obtain a sufficient stirring effect, the distance d ₁ between the first plate blade 3 and the second plate blade 4a and the distance between the third plate blade 5 and the second plate blade 4b must be set. It is preferable that the distance d ₂ is approximately 1/4 to 3/4 of the width D of the second blades 4a and 4b, respectively.

Further, the angles of inclination θ ₁ and θ _{2 of the first blade 3 and the third blade 5} are preferably about 30 to 60 degrees, particularly about 45 degrees.

According to the stirrer 1 for molten glass shown in FIGS. 1 to 4, when the stirrer 1 is rotated counterclockwise in plan view, the surface of the glass melt 6 is moved by the inclined surface of the first plate blade 3. It is drawn downward along the rotation axis 2, that is, inward. Further, the bottom base of the glass melt 6 is scraped up along the rotating shaft 2 by the inclined surface of the third plate blade 5, that is, toward the inside. Then, the flow of the substrate from above and below passes through the second plate blades 4a, 4 at the center of the stirring tank 7.
Stir thoroughly at step b. Furthermore, the water is then split again into two flows, an upper flow and a lower flow, on the wall surface of the stirring tank 7, and flows toward the substrate surface side and the bottom side. Therefore, the surface and bottom substrates, which are difficult to stir with conventional stirrers, are guided to the center of the stirring tank 7, and the material that is parallel to the axis of the rotating shaft 2 is
Since the second plate blade 4 at the intermediate position is used to stir the glass melt 6 in the circumferential direction, the glass melt 6 can be efficiently stirred and homogenized. Note that even if the rotating direction of the stirrer 1 is reversed from the above, there is no difference in the stirring and homogenizing ability, only that the flow direction of the glass melt 6 is reversed.

The embodiment shown in FIGS. 1 to 4 is an embodiment of the present invention, and the present invention is not limited to what is shown in the figures. Various aspects can be adopted in terms of the position, etc., without departing from the gist of the present invention.

For example, as shown in FIG.
a and 4b can be installed in the radial direction of the rotating shaft 2, or can be installed at a predetermined angle with respect to the tangential direction of the rotating shaft 2, as shown in FIG. Also,
As shown in FIG. 7, the blades 4a and 4b shown in FIG. 2 can be mounted offset in the axial direction of the rotating shaft 2. Furthermore, as for the first plate blade 3 and the third plate blade 5, as shown in FIGS. 8, 9, and 10, the attachment position, direction, spacing, etc. with respect to the second plate blade 4 may be changed. You can also do it. However, from the viewpoint of stirring efficiency, those shown in FIGS. 1 to 4 are most preferable.

As mentioned above, there is no particular restriction on the number of each plate blade, but as shown in FIG. If the stirring power of the first and third plate blades becomes excessively large, sufficient stirring effect may not be obtained, so the first and third plate blades are It is preferable to use one having appropriate stirring power.

In the stirrer of the present invention, the first
- In addition to the third plate blade, fourth and fifth plate blades can also be provided. Further, the size of each plate blade can also be changed depending on the shape of the stirring tank.

Examples will be described below.

Experimental Example 1 Using the stirrer for molten glass of the present invention shown in FIGS. 1 to 4, it was placed in the glass melt in the stirring tank 7 as shown in FIG. Rotated counterclockwise in plan view.

As a result, in the upper part, the surface substrate of the glass melt 6 is drawn downward along the rotation axis 2 by the first plate blade 3, and in the lower part, the bottom substrate of the glass melt 6 is drawn upward along the rotation axis 2. He was scooped up, and furthermore,
The base material of such a flow collides at the center of the stirring tank 7 and is stirred in the circumferential direction by the second plate blade 4.
Thereafter, the mixture was split into two streams again at the wall of the stirring tank 7 and flowed to the surface and the bottom.

Therefore, the glass melt 6 was stirred evenly and uniformly from the surface to the bottom substrate.

In addition. In this case, the same effect was obtained even when the rotating direction of the rotating shaft 2 was reversed.

Experimental Example 2 The stirring ability of the conventionally commonly used spiral stirrer 10 shown in FIG. 11 and the stirrer 1 of the present invention shown in FIGS. 1 to 4 was investigated.

Add a certain amount of colored liquid around the rotating shaft to polybutene with the same kinematic viscosity as the glass melt with specific gravity 2.5 and viscosity OGN = 2.87 in a stirring tank, and rotate it at the same rotation speed for a certain period of time using each stirrer. Stirred. After that, the liquid in the stirring tank is sampled a certain number n, the concentration xi of the colored liquid is determined, and its variance value σ ² = _o 〓 ⁱ (xi−
x) Homogenization ability was evaluated by ² /n.

As a result, the dispersion value of the spiral stirrer 10 is σ ² =0.673, while the dispersion value of the stirrer 1 of the present invention is σ ² =0.396, and the stirrer of the present invention has a significantly higher stirring ability than the conventional stirrer. proved to be high.

Embodiment 3 As shown in FIG. 5, the second plate blades 4a and 4b are arranged in the radial direction of the rotating shaft 2, and as shown in FIG. 8, the first plate blade 3 and the third plate blade 5 are attached. Stirring was performed in the same manner as in Experimental Example 1 using a stirrer 1A provided in the circumferential direction of the rotating shaft so as to be located away from the second blade 4.

As a result, compared to the case of Experimental Example 1, the flow of drawing the surface substrate into the interior and scooping up the bottom substrate became weaker, and the homogenization ability decreased.

Experimental Example 4 As shown in Fig. 9, the first plate blade 3 and the third plate blade 5 are placed in the tangential direction so that they are at the farthest position from the second plate blade 4 in the circumferential direction of the rotating shaft. Stirring was performed in the same manner as in Experimental Example 1 using the provided stirrer 1B.

As a result, as in Experimental Example 3, sufficient homogenization ability was not obtained.

Experimental Example 5 As shown in FIG. 7, a stirrer 1C in which the distance between the first blade 3 and the second blade 4a and the distance between the second blade 4b and the third blade are zero
Stirring was performed in the same manner as in Experimental Example 1.

As a result, no flow of the glass melt was formed between the blades 3 and 4a and between the blades 5 and 4b, and almost all of the glass material passed above or below the blades 4a and 4b. Compared to the case of Example 1, a sufficient homogenization effect could not be obtained.

Experimental Example 6 As shown in Fig. 10, the first blade 3 and the third blade
Stirring was carried out in the same manner as in Experimental Example 1 using a stirrer 1D provided with two blades 5 each.

As a result, the flow that draws the surface and bottom substrate of the glass melt into the interior becomes stronger, but the upper and lower blades 3,
Since the flows caused by 5 were balanced, the glass melt was divided into two upper and lower layers with a nearly horizontal boundary surface, and as compared to the case of Experimental Example 1, it was not possible to sufficiently homogenize the glass melt.

[Effects of the invention] As detailed above, according to the stirrer for molten glass of the invention, it is possible to efficiently stir the surface substrate and the bottom substrate, which were difficult to stir and homogenize with conventional stirrs. , an extremely uniform glass melt can be obtained.

In particular, according to the stirrer for molten glass of the present invention, excellent stirring effects can be obtained even at low speed rotation, so glass melt, which has high viscosity even at high temperatures, can be uniformly stirred at a low rotation speed that does not apply undue force to the stirrer. This is extremely advantageous.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a stirrer for molten glass according to an embodiment of the present invention, FIG. 2 is a cross-sectional front view of a stirring tank using the stirrer for molten glass shown in FIG. 1, and FIG. FIG. 4 is an end view of a cross section taken along the line of FIG. 5 and 6 are cross-sectional views of the second plate blade showing other embodiments of the present invention, and FIGS. 7, 8, 9, and 10 are respectively It is a schematic diagram which shows the attachment position of the board|plate blade based on a different Example. FIG. 11 is a schematic diagram showing a conventional spiral type stirrer. 1... Stirrer for molten glass, 2... Rotating shaft, 3... First plate blade, 4, 4a, 4b... Second plate blade, 5... Third plate blade.

Claims (1)

[Claims for Utility Model Registration] (1) A rotating shaft installed in the vertical direction, and first, second, and third blades arranged in at least three stages from above to below the rotating shaft. The upper first plate blade is installed at an inclination so as to have a positive or negative elevation angle with respect to the rotation direction, and the middle second plate blade has its plate surface aligned with the axis of the rotation axis. The lower third blade is installed in the direction of the rotation direction.
A stirrer for molten glass, characterized in that it is installed at an angle so as to have an angle of elevation opposite to that of the plate blades. (2) Two second blades are provided, each extending in a tangential direction from the circumferential surface of the rotating shaft, and
The stirrer according to claim 1, which is arranged symmetrically with respect to the axis of the rotating shaft. (3) One of the first and third blades is provided, and the first blade is connected to one of the second blades.
The stirrer according to claim 2, wherein the third plate blade is located above the second plate blade, and the third plate blade is located below the other second plate blade. (4) The lower edge side of the first plate blade is the side to which the one second plate blade is attached, and the upper edge side of the third plate blade is the side to which the other second plate blade is attached. The stirrer according to claim 3 of the utility model registration, which is provided on the attached side. (5) The distance between the first blade and the second blade and the distance between the second blade and the third blade are 1/4 to 3/ of the width of the second blade, respectively. 4. The stirrer according to claim 3 or 4 of the utility model registration claim.