JPS59197363A - Electromagnetic stirrer - Google Patents

Abstract

PURPOSE:To provide an electromagnetic stirrer which prevents intrusion of cooling water into a cylindrical iron core of an electromagnetic stirrer for stirring the unsolidified part of a continuous casting even if cooling water is forcibly circulated by providing coils in the cavities of the plastic iron core on the inside of a plate which partitions watertightly the iron core. CONSTITUTION:A cylindrical iron core 5 of an electromagnetic stirrer disposed to enclose a casting 1 is fixed into a box body by means of side plates 6 and the inside of the core 5 is covered by a partition plate 7 of a nonmagnetic material and is welded water tightly to the plates 6. A plastic core 9 formed by fixing the iron powder projecting tooth parts 9c forming axial groove parts 9b in an annular parts 9a by a plastic is fixed to the inside of the plate 7. Coils 8 are inserted into the groove parts 8b and are fixed by wedges 10. Then even if cooling water is admitted through a water feed port 3a into said box body and is discharged through a water discharging port 3b, the iron core 5 does not contact with the cooling water and is kept free from intrusion of the cooling water and therefore the iron core withstand long-term use.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electromagnetic stirrer disposed at a position where an unsolidified portion exists in a continuously cast product.

[Technical background of the invention and its problems]

In recent years, continuous casting has been adopted in the steel manufacturing industry, and the cast product pulled out of the mold is rapidly cooled from the outside, so metallurgically the metal structure becomes coarse columnar crystals, and cavities and impurities segregate in the center. Therefore, in order to improve these problems, the unsolidified part of the cast product is solidified and cast while being stirred with an electromagnetic stirrer to improve the material quality.

An electromagnetic stirrer, particularly one of the rotating magnetic field type, is installed in a very narrow space of continuous casting equipment surrounding a cast product whose surface is at a high temperature of 1000° C. or higher, so it receives a large amount of radiant heat from the cast product. Since the electromagnetic stirrer is an electric machine, it has an insulator, and the heat resistance limit of the insulator is 180°C or less. Therefore, in order to operate reliably over a long period of time, it is necessary to remove the radiant heat that the electromagnetic stirrer receives. Cooling is required.

For this reason, in conventional magnetic stirrers, the case surrounding the inductor is cooled with a water-cooled jacket, and the heat generated by the coil is cooled by forced draft or by flowing cooling water close to pure water through the conductor of the hollow conductor coil. However, the structure is complex and failures are likely to occur.

There is also a method of cooling the inductor coil and iron core by immersing them in cooling water, but since the iron core is immersed in water, it causes rust on the iron core and adheres to the coil, which obstructs the flow of cooling water. Ta.

[Purpose of the invention]

The present invention prevents cooling water from entering the iron core even when the cooling water is forcedly circulated, and provides a highly reliable electrical appliance that can withstand long-term use.
The purpose is to provide a magnetic stirrer.

[Summary of the invention]

In order to achieve the above object, in the present invention, a cylindrical iron core is watertightly covered with a partition plate made of a non-magnetic material, and a plastic iron core is formed by hardening iron powder with plastic on the inside of the partition plate and forming a hollow space in the axial direction. To provide an electromagnetic stirrer characterized in that the stirrer is fixed, a coil is inserted into a space, and the stirrer is fixed with a spring.

[Embodiments of the invention]

An embodiment of the present invention shown in the drawings will be described below. In Fig. 1, the electromagnetic stirrer is arranged to surround a cast product (1), and an annular mirror plate (4a) made of stainless steel is placed on the upper and lower surfaces of an inner wall (2) made of non-magnetic material and an outer wall (3) made of stainless steel.
, (4b), and a cylindrical iron core (5) on which annular electric iron plates are laminated is attached to the outer wall (3) with stainless steel side plates (6a) and (6b). The iron core (5) is fixed, and the inside of the iron core (5) is covered with a partition plate (7) made of a non-magnetic material, which is welded to the side plates (6a) and (6b) in a watertight manner. Partition # (
A plastic iron core (9) with protruding teeth (9c) forming a groove (9h) into which the coil (8) is inserted into the annular portion (9a) is fixed to the inside of the coil (7). The plastic core (9) is made by mixing iron powder with plastic, such as an organic binder, and molding and solidifying it.The grooves (9b) are formed by molding or cutting.1. Ru. Insert into the groove (9h),
Next, the operation of the coil (8) will be explained. Plastic iron core (9) is made of iron powder, that is, fine iron particles covered with plastic, and is an electrically poor conductor, and the eddy current loss due to magnetic flux is small, so it is different from conventional iron cores made of laminated electric iron plates. In comparison, the magnetic permeability is slightly lower, but in an electromagnetic stirrer, the magnetic flux density on the surface of the iron core is about several thousand Gauss at most, so it rarely causes a problem and does not cause rust.

Cooling water GO flows in from the water supply port (3a) and flows into the water supply side header I! il), the flow rate to each part in the circumferential direction is adjusted, and the flow is controlled through the passageway between the plastic core (9) and the inner wall (2) and between the wires of the coil (8) housed in the groove (9a). Waterway I! The water is divided into two parts i and 2, collected at the drain side header t54, and drained from the drain port (3b). The passageway (52) cools the radiant heat received from the casting (1) to the inner wall (2), and the passageway (52) cools the Joule heat generated from the coil (8).The iron core (5) is connected to the side plate (6a), ( 6b) Partition plate (because it is covered watertight by force, it does not come into contact with the cooling water and is indirectly cooled by the cooling water, and the back space of the iron core (5) does not require cooling by forced ventilation, but If the magnetic flux density is high, use forced ventilation.

FIG. 4 shows another embodiment, in which a plastic core (9)
The tooth part (9c) is used as a partition plate (7
) and is fixed to the plastic core (
9) does not have the annular portion (9a), so the diameter of the iron core (5) is also reduced, and the electromagnetic stirrer is made smaller.

The above explanation was about the electromagnetic stirrer in the casting part, but
For electromagnetic stirrers in molds which are also required to be within small dimensions, they can ultimately be applied in exactly the same way.

〔Effect of the invention〕

As described above, according to the present invention, in an electromagnetic stirrer, a cylindrical iron core is watertightly covered with a partition plate made of a non-magnetic material, and iron powder is hardened with plastic on the inside of the partition plate to form a cavity in the axial direction. By fixing the iron core and inserting the coil into the empty space, the iron core can withstand long-term use without rusting due to cooling water.The plastic core and coil are directly cooled, and the plastic core is It has high rust resistance, and the cooling water passages are not clogged with rust and can maintain good cooling, making it highly reliable. It also has excellent effects such as being compact and being able to fit within the narrow limits of continuous casting equipment.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing one embodiment of the electromagnetic stirrer of the present invention, Fig. 2 is a transverse sectional view taken along line A-A in Fig. 1, and Fig. 3 shows the main parts of Fig. 2. Cross-sectional view, FIG. 4 is a cross-sectional view showing essential parts of another embodiment. 1... Cast product 5... Iron core 7...
Partition plate 8... Coil 9... Plastic core 98... Annular part 9b... Groove part
9c...teeth Part 10...Kyo agent patent attorney Inoue-male (power figure 1)

Claims (1)

[Scope of Claims] 1. An iron core that is disposed at a position where an unsolidified part exists in a cast product to be continuously cast and is wound with a coil that generates a rotating magnetic field is housed in a box and cooling water is circulated. In an electromagnetic stirrer for cooling, the plastic core is formed into a cylindrical shape, is watertightly covered with a partition plate made of a non-magnetic material, and has iron powder hardened with plastic on the inside of the partition plate to form a cavity in the axial direction. An electromagnetic stirrer, characterized in that the stirrer is fixed, and a coil is inserted into the space and fixed with a wedge. 2. The electromagnetic stirrer according to claim 1, wherein the plastic core has teeth protruding from the inside of the annular shape to form a cavity. 3. The electromagnetic stirrer according to claim 1, wherein the plastic core has teeth fixed thereto at intervals on the inside of the partition plate.