JPS5926597B2 - Electromagnet for lifting iron pieces inside molten aluminum - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lifting electromagnet used for lifting deposited iron pieces etc. in high-melt aluminum.

For example, in the process of recycling aluminum scrap into aluminum ingots in a reverberatory furnace, if the scrap is an aluminum casting into which iron parts have been cast, the iron parts will be deposited at the bottom of the furnace as iron pieces. .

When this deposited iron piece is left in an aluminum fermentation bath with a temperature of about 600°C to 700°C for a long time, it gradually becomes highly molten in parts, which mixes with the aluminum and improves the quality of the finished aluminum ingot. It is necessary to remove the iron piece before it melts, as it causes a decrease in the iron content.

In addition, in order to take out the iron pieces deposited at the bottom of the furnace using a lifting electromagnet, it is necessary to avoid the coil part coming into contact with the molten aluminum, which has a depth of 600 to 800 mm. It is necessary to make the magnetic poles longer.

However, simply extending the magnetic poles of a conventional electromagnet would result in an extremely heavy overall weight, and would require a large crane to suspend the electromagnet, which is disadvantageous.

On the other hand, most of the iron pieces in the aluminum core are small and scattered at the bottom of the furnace, so effective recovery is required.

The present invention solves these problems and provides an electromagnet of this type that can intensively increase the magnetic flux density of the magnetic pole attraction part without significantly increasing the weight of the electromagnet itself, thereby ensuring attraction to the iron piece to be taken out and efficiently recovering the iron piece. The illustrated embodiment will be described below.

1 and 2 show a half-cut front view and a bottom view of one embodiment. is a yoke, 2 is a cylindrical inner pole connected to the yoke 1, 3 is an annular outer pole connected to the yoke 1, 4 is a coil wound around the inner pole 2, and 5 is the top surface of the yoke 1 A hanging metal fitting 6 protruding from the inner pole 2 is a plurality of magnetic connecting members arranged and connected in a radial manner so as to extend downward from the lower end of the inner pole 2. At each lower end thereof, there is provided a hanging metal member 6 extending radially outward (in the radial direction). A magnetic pole piece 7 is integrally formed.

Reference numeral 8 denotes an annular magnetic connecting member connected to the lower end of the outer pole 3 so as to extend downward, and its cross-sectional area (in the horizontal direction) is smaller than that of the outer pole 3. A pair of magnetic pole pieces 9 are arranged in a row between the pieces 7 and project inwardly in the radial direction, and the circumferential wall between each of these magnetic pole pieces 9 has a notch 1.
0, thereby reducing the magnetic path cross-sectional area of the lower end of the connecting member 8.

Note that the protrusion lengths of the magnetic pole pieces 7 and 9 in the radial direction are set so that they do not overlap each other in the circumferential direction.

One embodiment of the present invention is constructed as described above, and when taking out the iron pieces sunk to the bottom of the furnace, the downward length of each connecting member 6, 8 is longer than the depth of the aluminum core bath in the furnace. Therefore, the lower part of the connecting member is sunk into the aluminum core bath, scattered or deposited on the bottom of the furnace, and then the electromagnet is pulled up and the iron pieces are taken out.In this case, the iron pieces scattered on the bottom of the furnace are not left behind. In order to attract and collect objects, the magnetic field generated by the magnetic poles does not need to reach a deep part of the object to be attracted, and it is important to increase the magnetic flux density at the tip of the magnetic pole as much as possible.

In this regard, in this embodiment, the part that directly attracts the object is made up of a plurality of protruding magnetic pole pieces, and at the same time, the lower end of the connecting member is cut out to partially reduce the magnetic path area of that part. This increases the number of places where the magnetic flux density is concentrated, which increases the amount of debris scattered at the bottom of the hearth, and can be expected to achieve efficient collection.

FIGS. 3 and 4 show examples in which the polar connecting member 6 connected to the inner pole 2 is composed of a cylinder and a cylinder, and FIG. In addition, Fig. 6 shows cases in which a cylinder is used, the lower part of the cylinder is notched, and the amount of the notch increases as it goes downward. However, especially in the embodiments shown in FIGS. 5 and 6, the cross-sectional area is gradually reduced as it goes downward, so that magnetic saturation in the upper part can be avoided, and at the same time, concentration of magnetic flux density in the lower part can be promoted. You can expect good results.

As is clear from the above, the present invention connects the magnetic pole piece to the original magnetic pole via the magnetic coupling member, so that the coil part does not come into contact with the molten aluminum or come close to the point where it is affected by the iron pieces scattered at the bottom of the furnace. The connecting member that magnetically and mechanically connects the original magnetic pole and the added magnetic pole piece can be made of a plate, pipe material, small-diameter cylindrical material, etc. ,
Since its cross-sectional area is made smaller, the weight of the entire electromagnet does not increase.

For example, in the case of the embodiment shown in FIGS. 1 and 2, the diameter is 900 mm.
The weight of the entire electromagnet is approximately 1,600 kg in a 1 m long electromagnet in which the conventional magnetic poles are illegally extended by a length of 5, whereas the weight of the electromagnet of the present invention is only 900 kg.

In addition, since the part where the diameter-reduced iron pieces are attracted has many sharp parts formed by the magnetic pole pieces, there are many places where the magnetic flux density is concentrated in that part, which increases the amount of iron pieces scattered at the bottom of the furnace and increases the efficiency. We can expect a good recovery.

Incidentally, in the conventional electromagnet that does not have the above-mentioned magnetic pole piece, the magnetic flux density of the magnetic pole is uniform, and is 6000 Gauss at the corner of the inner pole.
2000 Gauss at the corner of the outer pole rises to 8000 Gauss at the tip of the magnetic pole piece of the present invention and 4000 Gauss at the tip of the outer pole.

Furthermore, according to the present invention, since there is no part where the NSS pole pieces overlap each other in the circumferential direction, there is almost no part of the magnetic poles that face each other within a gap of the same width, and even if there is, the area where the two face each other is extremely small. Therefore, there is no problem that the magnetic flux is dispersed from the large area portions where the two poles face each other, and the magnetic flux is concentrated on the small area portions of each pole piece, making it possible to effectively collect the scattered iron pieces.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, and FIG. 1 and FIG. 2 are a half-cut front view and bottom view of one embodiment, and FIGS. 3 to 6 are cross-sectional views of the inner magnetic pole part. be. 2...Inner pole, 3...Outer pole, 6,8...
...Magnetic connecting member, 1,9...Magnetic pole piece.

Claims (1)

[Claims] 1. A magnetic connecting member having a smaller cross-sectional area than the lower end of the outer pole of a round electromagnet with a cylindrical inner pole and an annular outer pole is connected, and both of these connecting members are An electromagnet for lifting an iron piece in m-molten aluminum, characterized in that a plurality of magnetic pole pieces are provided on opposing surfaces of the lower end portion, protruding approximately in the radial direction, and whose north and south poles do not overlap each other in the circumferential direction.