JPS6045929B2 - Microbubble dispersion device - Google Patents

Description

[Detailed description of the invention] The present invention relates to an apparatus for atomizing and dispersing bubbles.

There are methods for removing gases such as hydrogen and inclusions such as aluminum and magnesium oxides in the molten aluminum by releasing an inert gas such as nitrogen gas or argon gas in the form of bubbles into the molten aluminum. In order to promote the reaction, there is a gas-liquid contact method in which gas is bubbled into the liquid.
,↓day Λ, J to 3゛Aμ LC sa! In order to achieve good contact between 14-&L, it is required to make the bubbles as fine as possible and to disperse them uniformly in the liquid. SUMMARY OF THE INVENTION An object of the present invention is to provide a bubble atomization and dispersion device that meets the above requirements, has a simple structure, and is easy to operate.

Hereinafter, the present invention will be specifically explained with reference to embodiments of the drawings.

1 and 2, the bubble atomization and dispersion device according to the present invention includes a tank 1, a rotating shaft 2 disposed in the tank 1, and a bubble atomizing device attached to the lower end of the rotating shaft 2. It consists of a dispersion rotating body 3 and a gas supply pipe 5 arranged at the bottom of the tank 1.

Molten aluminum 4 is placed in the tank 1. The rotating body 3 is located in the molten metal 4 at a required distance from the tank bottom. The rotating shaft 2 is adapted to be rotated at its upper end by a rotational drive device. A male thread 6 is cut into the lower end of the coaxial 2. The rotating body 3 has a circular shape when viewed from above, the top surface 7 is a J-shaped spherical surface, and the bottom surface 8 is a flat surface. A female threaded portion 9 is vertically formed at the center of the top of the rotating body 3 . The rotating body 3 is attached to the lower end of the rotating shaft 2 by screwing this into the male threaded portion 6 of the rotating shaft 2. A plurality of vertical grooves 12 are formed in the peripheral gate 11 of the rotating body 3 at equal intervals. Further, the opening 10 of the gas supply pipe 5 faces the center of the bottom surface of the rotating body 3 from directly below. It is advantageous to have a smaller distance between the bottom surface of the rotating body 3 and the opening 10 of the gas supply pipe 5, and it is usually 50Wr! ! It is within l. In the bubble atomization and dispersion device configured as described above, the rolling body 2 is rotated at high speed by a drive device, and an inert gas is introduced into the gas supply pipe 5 from the gas supply device.

The inert gas is supplied to the bottom surface 8 of the rotating body 3 through the opening 10. Then, the inert gas spreads along the bottom surface 8 of the rotating body 3 from the center to the periphery, and forms a thin gas layer along the bottom surface 8 of the rotating body 3 due to the hydraulic pressure. The same layer is then fragmented by the shearing action and centrifugal force caused by the rotation of the rotating body 3, and fine bubbles are formed and dispersed from the periphery of the rotating body 3. Furthermore, the diffused bubbles are crushed by the vertical grooves 12 and made even finer. Further, the liquid is well stirred by the vertical grooves 12, so that air bubbles are uniformly dispersed throughout the tank. Since the top surface 7 of the rotating body 3 is a convex spherical surface, the liquid circulates almost throughout the tank as shown by arrow A in FIG.

The flow of this liquid causes the fine bubbles to be uniformly dispersed within the tank. Note that the top surface 7 of the rotating body 3 is not limited to a convex spherical surface, and may be a surface that does not expand downward, for example. FIG. 3 shows a first modification of the rotating body, in which top radial grooves 13 are formed on the top surface 7 of the rotating body 3, and these communicate with the vertical grooves 12, respectively. In this case, the top radial groove 1
3 further promotes the miniaturization of bubbles, and the same groove 13
Stir the liquid well. As a result, the effect of uniformly dispersing bubbles is further improved. Also, as shown by the chain line in Figure 3,
A vertical groove 14 that does not communicate with each of the top radial grooves 13 may be formed at the peripheral edge of the rotating body 3 between the top radial grooves 13. Figures 4 and 5
The figure shows a second modification of the rotating body. A recess 15 is formed in the center of the bottom surface 8 of the rotating body 3.

In this case, the gas supplied from the hollow portion is temporarily accumulated in the recess 15 to form a top layer. Then, as the rotating body 3 rotates, the same layer is finely divided and further refined while being discharged toward the circumferential edge. Therefore, even finer bubbles are formed. 6th
FIG. 7 shows a third modification of the rotating body, in which a bottom radial groove 16 is formed in the bottom surface 8 of the rotating body 3. In this case, the gas layer formed on the bottom surface 8 of the rotating body 3 is crushed by the bottom radial grooves 16, and is further divided into fine particles.
Therefore, the miniaturization of the bubbles is further promoted. Furthermore, since the liquid is well stirred by the bottom radial groove 16, the effect of uniformly dispersing bubbles is further improved. 8 and 9 show a fourth modification of the rotating body, in which a recess 15 is formed in the center of the bottom surface 8 of the rotating body 3, and a bottom portion is formed from the recess 15 to the periphery of the bottom surface 8. Radial grooves 16 are formed.

In this case, a combined effect of the second modification and the third modification is exhibited.In the third and fourth modifications, the bottom radial groove 16
Since the grooves also serve as bubble guide grooves, the bubbles are released radially from the rotating body 3.

Therefore, bubbles are not localized within the tank, and uniform dispersion is achieved in this respect as well. In the bubble dispersion device according to the present invention, the bubbles are made as fine as possible,
For uniform release into the liquid, the shape and size of the rotating body, the rotation speed, the distance of the rotating body from the bottom of the tank, etc. are important factors.

The shape of the rotating body is preferably a disc. It is preferable that the rotating body has a larger diameter. The higher the rotation speed, the better, usually 700 to 3000 r'. P. m is good. The rotation speed is 700r. p. If it is less than 300 m, the bubbles will not become finer.
0r'. P. If it exceeds m, a vortex is generated around the rotating shaft, and reaction products, impurities, etc. floating on the liquid surface are drawn into the liquid, which may have an adverse effect on the liquid. To prevent swirling currents, it is recommended to place a baffle plate inside the tank. The distance between the bottom of the rotating body and the bottom of the tank is 5 to 100Tn! n is preferred.
5? Otherwise, there is a risk that the rotating body will come into contact with the tank bottom.
If it exceeds 100 WL, the bubbles may not be distributed throughout the tank, and the density of microbubbles in various parts of the liquid may become non-uniform.

The gas supply pressure must be equal to or higher than the hydrostatic pressure. The amount of gas supplied is determined by the size of the tank, but if it is too small, the gas-liquid contact will be insufficient, and if it is too large, it will be difficult to make the bubbles finer and the efficiency of the gas-liquid contact will be poor. In the bubble atomization and dispersion device according to the present invention, a vertical rotating shaft 2 is disposed in a suspended manner in a tank 1, a rotary body 3 for air bubble atomization and dispersion having a flat bottom surface 8 is attached to the lower end of the coaxial shaft 2; Gas supply pipe 5 at the bottom of
is arranged so that its opening 10 faces the center of the bottom surface of the rotating body 3 from directly below, and at least one
Since two vertical grooves 12 are formed, the gas supplied from the gas supply pipe 5 to the bottom surface of the rotating body 3 forms a gas layer along the bottom surface, which is caused by the rotation of the rotating body 3. It is fragmented by shearing action and centrifugal force, forming fine bubbles.

The bubbles are then crushed by the vertical grooves 12 to become even finer. In addition, the liquid is well stirred by the vertical grooves 12,
Air bubbles are evenly distributed throughout the tank. Thus, according to the present invention, air bubbles can be made extremely fine and uniformly dispersed within the tank using a device with a simple structure.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG.
4 and 5 are vertical sectional views and bottom views showing a second modification of the rotating body, and FIGS. 6 and 7 are a sectional view corresponding to the third modification of the rotating body. A longitudinal sectional view and a bottom view showing a modification, and FIGS. 8 and 9 are a longitudinal sectional view and a bottom view showing a fourth modification of the rotating body. 1... Tank, 2... Rotating shaft, 3... Rotating body, 4...
- Molten aluminum, 5... Gas supply pipe, 8... Bottom surface, 10... Opening, 11... Periphery, 12... Vertical groove, 13... Top radial groove, 15... Recess , 16...
Bottom radial groove.

Claims (1)

[Claims] 1. A vertical rotating shaft 2 is suspended in a tank 1, and a rotary body 3 for bubble thinning and dispersion having a flat bottom surface 8 is attached to the lower end of the vertical rotating shaft 2. A gas supply pipe 5 is disposed, its opening 10 faces the center of the bottom surface of the rotating body 3 from directly below, and at least one vertical groove 12 is formed in the peripheral edge 11 of the rotating body 3. Device. 2. The device according to claim 1, wherein a top radial groove 13 is formed on the top surface 7 of the rotating body 3. 3. The device according to claim 1 or 2, wherein a recess 15 is formed in the center of the bottom surface 8 of the rotating body 3. 4. The device according to any one of claims 1 to 3, wherein the bottom radial groove 16 is formed on the bottom surface 8 of the rotating body 3.