JPH084920B2 - Rotating body for molten metal - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotating body such as a rotary blade for removing impurities in a molten metal such as aluminum or a rotary pump for sucking up the molten metal.

[Conventional technology]

In order to bubble the gas such as nitrogen, argon, chlorine, etc. blown into the molten metal for the purpose of floating and separating the impurities and hydrogen in the molten aluminum, the rotary blade 1 as shown in FIGS. I was using it. This rotary vane 1 is made of sintered carbon, and has a hollow shaft 2 fitted therein.
While rotating the rotary blade 1 by the shaft 2, a substrate such as nitrogen, argon or chlorine supplied from the hollow portion of the shaft 2 is bubbled into fine particles to diffuse into the molten metal to remove hydrogen.

As shown in FIGS. 5 (a) and 5 (b), the rotary pump 3 is made of sintered carbon and has a shaft 4 fitted therein.
The rotary pump 3 is rotated by the shaft 4,
The molten metal flow was generated by the holes 3a formed in the above, and the molten metal flow pushed up the molten metal field upward.

In general, the thicknesses X and Y of each of the rotors are 50 mm or more in order to improve the efficiency of atomizing the gas and pushing up the molten metal. Further, since the material of the rotating body is sintered carbon, which is consumed when rotating in the molten metal, the wall thickness is more convenient for prolonging the life of the rotating body.

[Problems of conventional technology]

However, since the rotary vanes 1 and the rotary pump 3 are made of sintered carbon, they are consumed in the molten metal and become thin immediately even if the wall thickness is made thick, resulting in a short life. there were. For example, the rotary vane 1 became unusable because the wall thickness became thin in about 50 hours, and the rotary pump 3 became unusable in about 3 months.

In addition, when these rotors are made of silicon carbide, silicon nitride, sialon, etc. without changing the wall thickness, when immersed in the molten metal, a large temperature difference occurs between the surface and the inside of the rotor, causing thermal stress. Therefore, there has been a problem that cracks and cracks are generated.

[Means for solving problems]

In view of the above, according to the present invention, the rotating body for molten metal is formed of ceramics of any one of silicon carbide, silicon nitride, and sialon, and a maximum thickness of 30 mm or less is obtained by performing partial lightening processing or the like. It was done.

〔Example〕

 Examples of the present invention will be described below.

As shown in FIGS. 1 (a) and 1 (b), the rotary vane 1 is made of any one of ceramics of silicon carbide, silicon nitride, and sialon, and has a thinned portion 1a. A substrate supply pipe 2 is fitted on the rotary blade 1 so that it can rotate.

Further, as shown in FIGS. 2 (a) and 2 (b), the rotary pump 3
Is any one of silicon carbide, silicon nitride, and sialon.
It is made of a kind of ceramics and has a thinned portion 3b. A shaft 4 is fitted to the rotary pump 3 so that it can rotate. Since the thinned portions 1a and 3b are formed in the rotary vane 1 and the rotary pump 3 to reduce the wall thickness in this manner, cracking due to heat shock can be prevented.

Now, with an outer diameter of 100 mm as shown in Fig. 3, various wall thicknesses T
The optimum thickness of the disk 5 can be determined by forming discs 5 with various materials as shown in Table 1, dipping it in molten aluminum, and then repeating the cycle of taking it out several times to check for cracks. Was tested. The test results are shown in Table 1.

From Table 1, it can be seen that if the wall thickness T is 30 mm or less, no crack is generated. Based on this result, as shown in FIG. 1 (b), the total thickness L of the rotary vanes 1 is 50 mm as before.
In addition to the above, when the lightening portion 1a is provided so that the maximum wall thickness M is 30 mm or less, no trouble such as cracks occurs during use, and sufficient performance as a rotary blade is exhibited. It can be used for about a month and a long life can be achieved.

Also in the rotary pump 3, as shown in FIG. 2B, the radial thickness R is the same as the conventional one, and the maximum thickness s or s'.
Is 30 mm or less, and at the same time, the thickness P in the thickness direction
When the lightening portion 3b was formed so that the maximum wall thickness Q was 30 mm or less, there was no trouble such as cracks and it could be used for about 6 months.

Needless to say, the shapes of the rotary vanes 1 and the rotary pump 3 are not limited to those in the above-described embodiment and may be changed as appropriate.

〔The invention's effect〕

As described above, according to the present invention, the rotating body for molten metal is made of any one ceramic of silicon carbide, silicon nitride and sialon, and has a maximum wall thickness of 30 mm.
By performing lightening processing etc. to make the following, there is little wear in the molten metal of the rotating body, and since the thickness is thin, cracks do not occur due to heat shock, so it has a long life, excellent It is possible to provide a rotating body for molten metal.

[Brief description of drawings]

FIG. 1 (a) is a perspective view showing a rotary blade which is an embodiment of the rotating body for molten metal of the present invention, and FIG. 1 (b) is the same figure (a).
It is an AA sectional view taken on the line. FIG. 2 (a) is a perspective view showing a rotary pump according to another embodiment of the present invention, and FIG. 2 (b).
FIG. 4B is a sectional view taken along line BB in FIG. FIG. 3 is a perspective view showing a test piece used in an experiment for investigating the optimum wall thickness. FIG. 4 (a) is a perspective view showing a conventional rotary blade, and FIG. 4 (b) is a sectional view taken along the line CC in FIG. 4 (a). FIG. 5 (a) is a perspective view showing a conventional rotary pump, and FIG. 5 (b).
FIG. 6B is a sectional view taken along line DD in FIG. 1: rotary blade, 2: gas supply pipe, 3: rotary pump, 4: shaft

Claims (1)

[Claims] 1. A rotating body for molten metal, which comprises a rotary vane for removing impurities of the molten metal in a molten metal such as aluminum and a rotary pump for sucking the molten metal, is made of silicon carbide, silicon nitride or sialon. A rotary body for molten metal, which is made of any one of the above ceramics and has a maximum thick portion of 30 mm or less.