JPH0371492B2 - - Google Patents

Description

Detailed Description of the Invention This invention is applicable, for example, to an electromagnetic desulfurization device that removes sulfur from the molten metal by electromagnetically stirring the molten metal and a desulfurizing agent, or to remove sulfur from the molten metal by electromagnetically stirring the molten metal and additives. The present invention relates to an electromagnetic induction stirring device suitable for use as a device for adjusting the components of.

Kyupora is widely used as a means of obtaining molten metal in iron foundries, etc., but since Kyupora uses coke as a fuel, the molten metal melted using Kyupora contains a high concentration of sulfur. On the other hand, demand and production of spheroidal graphite cast iron as a high-quality cast iron are increasing, but when using Kyupora molten metal, graphite spheroidization by adding a spheroidizing agent is not successful due to the sulfur content. Therefore, in the production of spheroidal graphite cast iron using Kyupora molten metal, a desulfurization step is generally provided before adding the spheroidizing agent. In this desulfurization step, it is necessary to add a desulfurization agent to the molten metal and to further stir it to promote the reaction, and generally a porous plug method, a gas injection method, etc. are used. However, when this porous plug method or gas injection method is used, the temperature of the molten metal decreases significantly due to stirring, so it is necessary to raise the temperature of the molten metal after desulfurization. For example, a groove-type induction furnace must be installed separately, which is a problem, especially in small-scale production plants, as the expense ratio for installing a heating furnace becomes large.

Therefore, the present applicant first developed an electromagnetic desulfurization device that can perform stirring and temperature raising at the same time. FIG. 1 is a cross-sectional view showing the configuration of this electromagnetic desulfurization apparatus, in which 1 is a cylindrical crucible with a bottom, 2 is a cylindrical communicating path that communicates with the bottom of the crucible 1 and extends diagonally upward to the right; 1
Reference numeral 5 denotes a gutter-shaped discharge port extending to the right from the upper end of the communication path 2, and this crucible 1, the communication path 2, and the discharge port 1
5 are both made of refractory material 3. 5 is wound around a strong cylindrical coil furnace material and placed in the crucible 1.
The yoke 6 is a coil that surrounds the coil 5 from the outside, and 6 is a plurality of yokes arranged radially around the outer periphery of the coil 5, although only a cross section is shown in the figure (see FIG. 2B). This yoke 6 forms a magnetic path outside the coil 5, suppresses leakage magnetic flux from the coil 5, and prevents heat generation due to eddy current generation in the steel materials that make up the outer wall of the device (not shown). This is well known in induction furnaces and the like. Further, the above-mentioned coil 5 is formed of a hollow copper tube, and during operation, forced cooling is performed by flowing water into the hollow part. 7 is Kyupora molten metal discharged from Kyupora, and 8 is a desulfurization agent whose main components are calcium carbide (CaS ₂ ) and calcium oxide (CaO).

When an alternating current is supplied to the coil 5 in the above-described configuration, a flow of molten metal as shown by the arrow in the figure occurs in the crucible 1, similar to an induction furnace, etc., and at the same time, heat generation occurs in the molten metal in the crucible due to the eddy current. happens. In this manner, the molten metal in the crucible is stirred, desulfurized, and heated, and the desulfurized molten metal 10 is discharged to the outside from the discharge port 15 through the communication path 2.

As described above, the electromagnetic desulfurization equipment developed by the present applicant can perform stirring and temperature raising at the same time, so it has an extremely large economic effect, but it has the disadvantages described below. Ta. Since the refractory material 3 is eroded by the slag generated during desulfurization, it is necessary to repair it periodically (about one week), but the electric desulfurization apparatus shown in FIG. 1 is troublesome to construct.
Since there is a communication path outside the coil 5, the arrangement of the yoke 6 is restricted and the induced heat generation of the external structure increases. Since the coil 5 is forcedly water-cooled, the cooling effect is transmitted to the communication path 2, and the temperature of the molten metal tends to drop in this portion.

In view of the above-mentioned circumstances, this invention allows stirring and temperature rise at the same time, allows for easy and quick construction of a furnace for repair, has no restrictions on the arrangement of yoke, and reduces the temperature of the molten metal being discharged. The present invention provides an electromagnetic induction stirring device that includes a crucible, a discharge port formed at the upper end of the crucible, and a device arranged around the crucible so as to extend along the outer periphery of the crucible and avoid the discharge port. It is characterized by comprising a wound substantially cylindrical coil.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2A is a sectional view of an embodiment of the present invention, and FIG. 2B is a view taken along the line A--A in FIG.
In this figure, parts corresponding to those in FIG. 1 are given the same reference numerals, and the yoke 6 is not shown in FIG. 2A.

The communication path 2 in FIG. 2A communicates with the bottom of the crucible 1 and then extends vertically upward to reach the discharge port 15, and is connected to the inside of the cylindrical coil furnace material 11 around which the coil 5 is wound. It is formed. In this case, the coil 5 is wound as shown in FIG. 3A or 3B. That is, in FIG. 3A, the coil 5 is moved diagonally upward from one end where the discharge port 15 of the coil furnace material 11 is formed to the other end, and diagonally downward from the other end to the one end. On the other hand, Fig. 3(b) shows a case in which the coil 5 is wound with a steep slope at the part where the discharge port 15 of the coil furnace material 11 is formed, and other windings are shown. The figure shows the case where the part is wound horizontally. In addition, the yokes 6, 6, etc. shown in FIG.
It can be placed anywhere without any restrictions.

Next, the case of manufacturing the above-mentioned embodiment will be explained.

First, a fourth core 20 is manufactured using an iron plate. This core 20 includes a portion 20a having the same shape as the crucible 1 and having a bottom surface, and a portion 20b having the same shape as the communicating path 2.
It consists of , and is formed hollow. Next, dry powdery refractory material 3 is put into the coil furnace material 11 to form the bottom part A shown in FIG. 2A. Then, the core 20 is placed on the bottom A, and the space between the coil furnace material 11 and the core 20 is filled with the powdery refractory material 3 described above. During this filling operation, a commonly used filling vibrator is used. After the filling of the refractory material 3 is completed, when the coil 5 is energized,
The core 20 is heated by induction, and the filled refractory material 3 is sintered by this heat. Next, when the Kyupora molten metal 7 is poured into the portion 20a of the core 20, the heat of the Kyupora molten metal 7 further advances the sintering of the refractory material 3, and the core 20 is melted and erased. and a communication path 2 are formed.

The above-mentioned manufacturing method is a well-known method called the so-called dry furnace construction method, and thus, in this embodiment, the crucible 1 and the communication passage 2 can be easily and quickly manufactured using the dry furnace construction method. can. Therefore, when the refractory material 3 is corroded by slag and needs repair, all the damaged refractory material 3 can be scraped off using a chisel or the like, and a new one can be manufactured again using the above-mentioned furnace construction method. Repairs can often be carried out in a very short time.

Next, referring to FIG. 5, another embodiment of the present invention will be described. This figure differs from the above-mentioned embodiment in that the communication path 2 shown in FIGS. 2A and 2B is
The discharge port 15 is directly connected to the upper end of the crucible 1 without forming a
This is the point where the

According to such a configuration, it is possible to construct and repair the furnace more easily and in a shorter time than in the above-described embodiment, and the temperature of the molten metal 1 decreases when it communicates with the communication path 2. It is possible to overcome the drawbacks of the conventional method.

Next, a case will be described in which an Al-Ti (aluminum-titanium) alloy is manufactured using the electromagnetic induction stirring device according to the embodiment described above. Generally Al−Ti
When producing alloys, Al, a non-ferrous metal, is melted in an open-well reverberatory furnace or a closed furnace.
The resulting molten Al is heated to the optimum temperature,
Furthermore, sufficient stirring must be performed after adding the Ti metal. Therefore, Al molten metal was introduced into the crucible 1 instead of the cupora molten metal 7 shown in FIG. 2A or FIG.
By supplying a predetermined alternating current to the coil 5, the Al molten metal is heated to the optimum temperature, and the Ti metal is melted.
Melts with molten Al. Furthermore, if the Al molten metal and the Ti base metal are continuously introduced into the crucible 1, the alloy molten metal is continuously discharged from the discharge port 15 of the crucible 1. In this way, since the heating and stirring are performed simultaneously, the Al molten metal and the Ti base metal are melted together very efficiently, and it is possible to continuously produce the alloy molten metal.

It should be noted that the electromagnetic induction stirring device according to the above-described embodiments is not limited to the above-mentioned applications, but can of course be used as a device for adding powdered additives to molten metal to adjust the components.

As explained above, according to the present invention, there is provided a crucible, a discharge port formed at the upper end of the crucible, and a winding which is arranged around the crucible and is wound along the outer periphery of the crucible and avoiding the discharge port. Since a substantially cylindrical coil is provided, furnace construction and repair can be carried out easily and in a short time, and there is an advantage that there are no restrictions on the position of the yoke placed around the coil. . In addition, the crucible and the communication passage may be in close proximity to each other, or may have no communication passage, so that the temperature of the molten metal in the crucible may drop when it is discharged. Conventional drawbacks can be overcome.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of an electromagnetic desulfurization device previously developed by the applicant, FIG. 2A is a sectional view showing the configuration of an electromagnetic induction stirring device according to an embodiment of the present invention, and FIG. 3A and 3B are both front views showing the method of winding the coil 5 shown in FIG. 2, and FIG. 4 is a view used when manufacturing the same embodiment. FIG. 5 is a perspective view showing the external appearance of the core 20, and a sectional view showing the structure of another embodiment of the present invention. 1... Crucible, 3... Insulation material, 5... Coil, 1
5...Discharge port.

Claims (1)

[Claims] 1. In an electromagnetic induction stirring device that simultaneously stirs and raises the temperature of molten metal by electromagnetic induction, there is a crucible into which the molten metal and additives are introduced, and a crucible that is formed at the upper end of the crucible and continuously discharges the molten metal to the outside. An electromagnetic induction stirring device comprising: a discharge port disposed around the crucible, and a substantially cylindrical coil wound along the outer periphery of the crucible and avoiding the discharge port.