JPH0230370A - Molten metal tap equipment - 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 [Field of Industrial Application] The present invention relates to a molten metal tapping device used for tapping molten metal from a container containing molten metal.

[Conventional technology]

A molten metal tapping device is known that includes a nozzle connected to the bottom of a container for containing molten metal, a sliding gate attached to the lower end of the nozzle, and an induction heating coil installed around the nozzle. .

[Problem to be solved by the invention]

In this conventional molten metal tapping device, when the metal in the nozzle is inductively heated by the magnetic flux from the coil, the magnetic flux reaches the sliding gate, causing the gate to be heated.

For this reason, there is a problem in that a high temperature resistant material or a special material that does not easily generate heat must be selected and used for the gate. Furthermore, since the magnetic flux reaches the gate as described above, there is a problem in that the gate consumes the magnetic flux, that is, a large loss of magnetic flux occurs. Note that if the coil is moved away from the sliding gate so that the magnetic flux from the coil does not reach the sliding gate, there will be a place in the nozzle where the induction heating cannot be performed, and the molten metal will solidify inside the nozzle, inhibiting the tapping of the hot water. There was a problem that occurred.

The present invention has been made in view of the above points, and its purpose is to provide a sliding gate made of molten metal that can be made unaffected by magnetic flux, and at the same time can significantly reduce loss of magnetic flux. The purpose of the present invention is to provide a hot water tap device.

[Means to solve problems]

In order to achieve the above object, the present invention takes the measures as described in the claims above, and its effects are as follows.

[Effect]

By opening the sliding gate, the molten metal in the container can be tapped through the nozzle.

In this case, the metal inside the nozzle can be heated by induction using the magnetic flux from the induction heating coil. The magnetic flux is prevented from reaching the sliding gate by the magnetic shielding plate. As a result, the temperature increase of the sliding gate and loss of magnetic flux due to the sliding gate are prevented.

〔Example〕

The drawings showing the embodiments of the present application will be described below.

In Fig. 1, reference numeral 1 indicates an induction furnace, which includes a furnace shell 2 made of a non-magnetic metal material such as non-magnetic stainless steel, a container 3 for containing molten metal, and an induction heating coil for melting disposed around the container 3. 4. A nozzle 5 connected to the bottom of the container 3, an induction heating coil 6 disposed around the nozzle 5, a sliding gate 7 attached to the lower end of the nozzle 5, and a connection between the induction heating coil 6 and the sliding gate 1-7. It is composed of a magnetic shielding plate 8 and the like interposed between them.

As is well known, the container 3 is composed of a concave main body 3a, a mass block 3b, a funnel 3C, etc., all of which are made of refractory material.

The nozzle 5 is also called a runner and has a cylindrical shape, the upper end of which is connected to a funnel 30 as shown.

The nozzle 5 is formed by firing a refractory material such as high alumina castable at 1700°C.

The inner periphery is made of a cylinder made of boron nitride, for example.

Next, the sliding gate 7 will be explained.
It is a housing made of a non-magnetic metal material such as non-magnetic stainless steel, and is attached to the furnace shell 2 via the magnetic shielding plate 8 and its mounting plate 20. For example, a mica plate is interposed between the housing 11 and the magnetic shielding plate 8 to electrically insulate the two. 1
Reference numeral 2 denotes a stationary plate connected to the lower end of the nozzle 5, which is made of a refractory material such as alumina, and the state of connection with the nozzle 5 is maintained by the housing 11. Reference numeral 13 denotes a slide plate which is attached to the housing 11 so that it can slide freely in the direction of the arrow. The slide plate 13 has a casing 1 made of a non-magnetic metal material such as non-magnetic stainless steel.
A closure body 15 made of a refractory material, for example, alumina, is housed within the chamber 4. A nozzle body 16 made of a refractory material such as alumina is fitted into a part of the closing body 15, and the nozzle body 16 is made of a refractory material such as alumina.
6 to allow the molten metal to flow out. 17 is a hydraulic cylinder for opening/closing operation, and its piston rond 17
A is connected to the slide plate 13 via a connecting rod 18.

Next, the magnetic shielding plate 8 is made of a conductive but non-magnetic material, such as W4 (aluminum or non-magnetic stainless steel may also be used), and is formed into an annular shape as shown in FIG. It is arranged to surround the furnace shell 2 and is attached to the furnace shell 2 using a mounting plate 20. 8a shown in FIG. 2 is a water passage provided inside the magnetic shielding plate 8;
The magnetic shielding plate 8 is formed hollow as shown in FIG. 1, and a part of the magnetic shielding plate 8 is partitioned off by a wall 8b. A water passage device (not shown) is connected to the connection ports provided at one end and the other end of the water passage 8a, and the cooling water is supplied to the connection ports provided at one end and the other end of the water passage 8a in the directions shown by the arrows 8c, 8d, and 8e.
It is passed as shown in .

In the induction furnace 1, when the sliding gate 7 is closed as shown in the figure, the metal in the container 3 is inductively heated by the magnetic flux applied from the coil 4 and becomes molten metal 22. For example, the coil 4 has a frequency of 3000Hz.
An alternating current for induction heating is provided.

When the molten metal 22 is tapped, an alternating current of, for example, 8000 Hz for induction heating is applied to the coil 6, and the magnetic flux generated by the coil 6 is applied to the runner 5a inside the nozzle 5. The metal in the runner 5a is heated by induction by this magnetic flux. Note that this induction heating may be started when the hot water is to be tapped, or may be started before that time.

In this state, the slide plate 13 is moved to the left by the cylinder 17, and the through hole 16a of the nozzle weight 6 is inserted into the fixed plate 1.
2, the molten metal in the container 3 flows through the through hole of the funnel 3c, the runner 5a of the nozzle 5, and the fixed platen 1.
2 and the nozzle body 16 through the through holes 12a and 16a.

In the case of tapping the hot water described above, induction heating by the magnetic flux from the coil 6 has the following effects. That is, even if the metal in the runner 5a solidifies at the start of tapping, it is melted and the tap starts smoothly. Further, during tapping, the fluidity of the metal in the runner 5a is maintained well (deterioration in fluidity due to low temperature is prevented), and tapping is performed smoothly.

The outflow of the molten metal can be stopped by returning the slide plate 13 to the state shown in FIG. 1 using the cylinder 17.

When the magnetic flux is emitted from the coil 6 as described above, the magnetic flux is caused by the electromagnetic shielding effect by the magnetic shielding plate 8, that is, when the alternating electromagnetic field (magnetic flux) from the coil 6 tries to pass inside the magnetic shielding plate 8. The eddy current generated in the magnetic shielding plate 8 blocks the passage of the electromagnetic field, thereby preventing it from spreading to the sliding gate 7. As a result, metal members such as the housing 11 and the casing 14 in the sliding gate 7 are not heated by induction, and no heat is generated in them.

FIG. 3 shows a state in which magnetic flux is shielded by the magnetic shielding plate 8, and the magnetic flux Φ emitted by the coil 6 hardly reaches the sliding gate 7.

In the case of induction heating using the coil 6, cooling water is passed through the passageway 8a of the magnetic shielding plate 8, and heat is removed from the magnetic shielding plate 8 by the cooling water. As a result, since the magnetic shielding plate 8 is formed of a non-magnetic material, it is difficult to receive induction heating due to the magnetic flux, and the magnetic shielding plate 8
The low-temperature conditions are well maintained.

The induction furnace in the above embodiments includes a vacuum induction furnace and an atmospheric induction furnace. Examples to which the molten metal tapping apparatus of the present application is applied include, in addition to the above-mentioned induction furnace, a holding furnace, a ladle, a tundish, an AF, and other molten metal processing furnaces.

Next, FIG. 4 shows an example of a different shape of the magnetic shielding plate.
This shows an example formed slightly larger than the example shown in the figure.

Even if the magnetic shielding plate 8 is formed in this manner, the magnetic flux shielding state by the coil 6 is not much different from that of the previous embodiment, and induction heating of the metal member in the sliding gate 7 does not occur.

Next, FIG. 5 shows a further different example of the shape of the magnetic shielding plate 8, in which a part thereof is provided with slits 23 in the radial direction.

In this example, the cooling water flows through arrows 8c, 8d, and 8.
It is better to do it like e.

〔Effect of the invention〕

As described above, in the present invention, when the molten metal in the container 3 is tapped, the sliding gate 7 is opened and the metal in the nozzle 5 is heated by induction, so that the metal can be easily tapped out from the container 3. be.

Furthermore, in the case of the induction heating, a magnetic shielding plate is provided between the induction heating coil 6 and the sliding gate 7 to prevent the magnetic flux emitted from the induction heating coil from spreading to the position of the sliding gate. 8, the sliding gate 7 attached to the nozzle 5 has the advantage of not being affected by magnetic flux. This has the effect that when designing the sliding gate 7, there is no need to consider magnetic flux when selecting its structure and materials, and the degree of freedom in design can be improved.

Moreover, in the above case, since magnetic flux does not go to the sliding gate 7, there is no large loss of magnetic flux in the sliding gate as in the conventional example, and furthermore, since the magnetic shielding plate 8 is made of a non-magnetic material, the magnetic flux is generated by itself. The magnetic flux loss can be significantly reduced compared to the conventional example, and
It also has the advantage of being energy efficient.

Furthermore, in the above case, since the cooling water removes heat from the magnetic shielding plate 8, there is an advantage that even if the magnetic shielding plate 8 is formed to be small in volume and its heat capacity becomes small, its low temperature state can be maintained. The fact that the magnetic shielding plate 8 can be made small in size means that the volume occupied by the magnetic shielding plate 8 between the induction heating coil 6 and the sliding gate 7 can be reduced, and as a result, the nozzle Due to the presence of the magnetic shielding plate 5, it is possible to prevent the occurrence of a place where the heating does not reach, which has the effect of preventing the molten metal from solidifying in the nozzle and inhibiting the tap flow.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application. Fig. 1 is a longitudinal cross-sectional view of an induction furnace, Fig. 2 is a plan view of a magnetic shielding plate, Fig. 3 is an explanatory diagram of a magnetic flux shielding state, and Fig. 4 is a magnetic flux shielding state. FIG. 5 is a vertical sectional view of a main part showing examples of different shapes of the shielding plates, and FIG. 5 is a plan view showing still further examples of different shapes of the magnetic shielding plates. 3... Container, 5... Nozzle, 6... Induction heating coil, 7... Sliding gate, 8... Magnetic shielding plate. Fourth

Claims (1)

[Claims] A molten metal tapping apparatus comprising: a nozzle connected to the bottom of a container for containing molten metal; a sliding gate attached to the lower end of the nozzle; and an induction heating coil disposed around the nozzle. An annular magnetic shielding plate made of a conductive and non-magnetic material is interposed between the coil and the sliding gate, and the magnetic shielding plate is provided with a water passage for passing cooling water. Tapping equipment for molten metal.