JPS5822888A - Electromagnetic agitator for molten metal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanism for an electromagnetic stirring device for molten metal (hereinafter referred to as molten metal) accumulated in a container.

For example, in an aluminum reverberatory furnace (specific configuration of molten metal container), after a certain amount of molten metal has accumulated, the aluminum material to be melted is immersed in the molten metal and melted while cutting off air (based on the purpose of preventing oxidation). To go. In this process, the temperature of the molten metal surrounding the aluminum material to be melted is lower than that of the molten metal in other parts, and a stirring action is inevitably required to increase the efficiency of melting the material to be melted. As a means for this purpose, for example, an inductor for generating a moving magnetic field is placed at the bottom of the reverberatory furnace, and the moving magnetic field generated from this inductor is applied to the molten metal in the furnace, giving a thrust to the molten metal and stirring it. It can be thought of as Jin. .

The main parts of this structure are as shown in FIG. 1, where 1 is a reverberatory furnace molten metal holding section, in which a refractory material ta is surrounded by an outer sheath tb (usually a magnetic plate). 2 is an inductor, placed at the bottom of the furnace,
The outer sheath Ik) facing the inductor 2 is made of a non-magnetic material, such as a stainless steel material 1b'l, to prevent magnetic short circuits. 8 is molten aluminum, and 4 is an aluminum material to be melted.

By the way, the following relational expression holds true for the distance Go between the surface of the inductor 20 and the molten metal a in the furnace in FIG.

BG=Bob(-TIIGo)... River(1
Here, BG... Magnetic flux density on the molten metal surface closest to the inductor BQ... Magnetic flux density on the inductor surface T −°
-Ball pitch On the other hand, the magnetic flux density B() required for stirring is fixed,
Even if the distance GQ changes, it is necessary to maintain a value above a certain value. Therefore, the distance G. As the magnetic flux density BG increases in equation (1), the magnetic flux density BG decreases, so the magnetic flux density BO on the inductor surface must be increased by an amount corresponding to the compensation for the finger-like attenuation of the magnetic flux density B().

However, when holding molten metal, the thickness of the refractory material 1a is required to exceed a certain level, and this requires the inductor surface magnetic flux density to reach a considerable value, which in turn increases the size of the inductor 2 and reduces efficiency. There was a drawback that the low F was extremely high. One way to eliminate this drawback is to bury the inductor in the furnace wall to reduce the distance G. Although it is conceivable to reduce this, it is difficult to put it into practical use because this configuration is particularly prone to damage to the expensive inductor by the molten metal, and maintenance and inspection of the inductor is also impossible.

The purpose of this invention is to improve the electromagnetic efficiency of the inductor by providing a core facing each magnetic pole of the inductor in the refractory material that forms the molten metal container, thereby increasing the thickness of the furnace wall without reducing the heat retention effect. It's in Ko-shichi.

The illustrated embodiment will be specifically described below. Second
The figure is a sectional view of a main part of the apparatus according to the present invention, and mechanical elements equivalent to those in FIG. 1 are designated by the same reference numerals. In FIG. 2, the inductor 2 consists of moving magnetic field generating magnetic pole iron cores 21) (magnetic poles 21)j, 2b2. ,．
2bn) and each of these magnetic poles 2b1.2b2...2
The coil 20 force installed against the bn is running.

0l-On is the core, each of the above 6 magnets 41i 2b1
It is provided in the refractory wall of the container by means such as embedding at a position opposite to ~2bn copper. And this core C1~Cn
protrudes from the inside of the non-magnetic material rb' toward the inductor 2, and faces each of the inductor magnetic poles 2b1 to 2bn.

In the above configuration, the molten metal 8 is maintained at a high temperature by a burner device (not shown), and the aluminum material 4 to be melted, which is poured into the molten metal 8, absorbs heat from the molten metal 8 and melts while being cut off from the outside air. As a result, around the aluminum material 4 to be melted, the molten metal is distributed at a considerably lower temperature than the molten metal in other parts that have just been melted. Therefore, when an AC voltage is applied to the coil 2C of the inductor 2, the magnetic flux straddles the magnetic poles 2bl to 2bn forming a one-ball pitch, and the magnetic flux advances as the voltage phase changes, causing a so-called moving magnetic field. 8, and the molten metal 8 receives a thrust due to the electric and magnetic action with the molten metal 8, and a stirring action is performed. By the way, according to this invention. The core held by embedding or the like in the refractory material of the molten metal container has almost negligible magnetic resistance compared to the refractory material. Therefore, the magnetic resistance until the magnetic flux produced by each magnetic pole 21) 1 to 2bn of the inductor 2 reaches the molten metal 8 is substantially only the portion corresponding to the distance G between the cores C4 to Cn and the molten metal 8, and is significant. A decrease is expected. As a result, the distance GQ in the first equation is reduced to the distance 1IIG1, so that the magnetic flux 1 from the inductor 2 can effectively contribute to increasing the thrust to the molten metal 8 at an exponential rate.

FIG. 3 is a sectional view of a main part showing another embodiment, which relates to a mechanism in which cores 01 to Cn are embedded inside a non-magnetic material for magnetic shielding. Such a configuration is a non-magnetic material IL, +
Although the magnetic resistance increases by -1 with respect to the thickness of 2
You can expect more than the configuration shown in the figure.

Although the above description has been made regarding stirring of molten metal in a reverberatory furnace, it goes without saying that this electromagnetic stirring device can be applied to any device that holds molten metal. In addition, the cores 01 to 2 do not necessarily have to be installed in the refractory material in a buried manner, but may be attached in an extensible manner, and the inductor is not limited to the bottom of the container, but may be placed on the side of the container.

As described above, the electromagnetic stirring device for molten metal according to the present invention has a structure in which a container holding the molten metal is provided with an inductor for stirring the molten metal, and a core is placed at a position facing each magnetic pole of the inductor to form a fireproof container. It was designed to be installed in the middle of the network.

Based on this configuration, the magnetic resistance of the magnetic path through which the magnetic flux emitted from each magnetic pole of the inductor reaches the molten metal is significantly reduced, and the thickness of the refractory wall facing the inductor of the molten metal container is not limited and can be used at high temperatures. can take a sufficient value for molten metal. This has traditionally been compounded by the need to use a large inductor with an extremely large capacity in order to obtain the required thrust on the molten metal through the refractory wall required by the vessel, and this invention provides the same thrust on the molten metal within the vessel. However, the practical benefits that can be achieved with a very small capacity inductor are large.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main part of a reverberatory furnace equipped with a conventional electromagnetic stirring device, and FIG. 2 is a detailed sectional view of the main part showing an embodiment of the present invention.
FIG. 3 is a schematic sectional view of main parts showing another embodiment of the present invention. l・・・・・・・・・・・・Molten metal container 1a
・・・・・・・・・・・・・・・Fireproof wall 2・・・・・・
......Inductor 2J~2bn...
...Magnetic poles C1 to Cn...Core 3...-
・・・・・・・・・・・・Molten metal applicant Shinko Electric Co., Ltd. agent Patent attorney Haruya Saito Figure 2

Claims (1)

[Claims] 1. In a configuration including an inductor that applies thrust to the molten metal and stirs the molten metal in a container holding the molten metal, the inductor faces the magnetic pole surface of each magnetic pole of the inductor, and the magnetic pole surface and the molten metal Each of the above J14ii inside the fireproof wall existing between
An electromagnetic stirring device for molten metal characterized by having a plurality of cores arranged in pairs.