JPH0571338B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spray cooling mold equipped with an electromagnetic stirring device that is applied to a mold of continuous casting equipment.

[Conventional technology]

FIG. 3 is a plan view of a conventional cooling mold for continuous casting equipment, FIG. 4 is a side view including a partial cross section of the same mold, and FIG. 5 is a view along the arrows including a partial cross section of FIG. be. In the conventional mold for continuous casting equipment, as shown in FIGS. 3 to 5, a cooling water chamber 3 is provided on the outer surface of a mold 1 having a rectangular cross-sectional shape. A vertical partition wall 3b is provided on the jacket 3a of the cooling water chamber 3, and a horizontal partition wall 3c for dividing the cooling water chamber 3 is provided approximately in the center of the partition wall 3b. In this cooling water chamber 3, cooling water is guided downward through a cooling water pipe 5, and further upward through a water channel 2 between the mold 1 and the partition wall 3b. to cool the mold 1. Further, in such a mold 1, an electromagnetic stirring coil 4 for stirring the molten steel in the mold was provided outside the jacket 3a of the cooling chamber 3. When cooling a continuous casting mold using such a cooling mold, conventionally, as shown in Figs. This was done by convective heat transfer between the cooling water.

[Problem that the invention seeks to solve]

By the way, in the conventional mold for continuous casting equipment, as described above, the electromagnetic stirring coil 4 is placed outside the jacket 3a that forms the water channel 2 in the mold cooling water, so the electromagnetic stirring coil 4 of the mold 1 and A gap is required between them, determined by the width of the waterway 2, the thickness of the jacket 3a, etc., and the power required for the coil is calculated based on this distance.

The magnitude of the thrust for stirring the molten steel in the mold 1 induced by the electromagnetic stirring coil 4 is inversely proportional to the square of the distance between the coil 4 and the mold 1. Therefore,
Design consideration was given to keep this distance as small as possible,
We strive to obtain high stirring power with as little electric power as possible.

However, since the electromagnetic stirring coil 4 is provided outside the jacket 3a, the distance between the coil 4 and the mold 1 is large, reducing the stirring ability.
As a result, there were drawbacks such as the need to increase the power capacity of the coil 4.

〔the purpose〕

The present invention is intended to eliminate the above drawbacks, and provides a spray cooling mold for continuous casting equipment equipped with an electromagnetic stirring device that minimizes the distance between the mold and the electromagnetic stirring coil. The purpose is to

[Means for solving problems]

In order to minimize the distance between the mold and the electromagnetic coil, the present invention (1) directly cools the mold by spraying, replacing the conventional jacket-type cooling with opposing water flow. (2) On the other hand, in spray-type mold cooling, the required amount of cooling water is maximum near the molten metal surface (also called the meniscus) in the mold, and decreases as it goes downwards (i.e., the flow rate decreases in the longitudinal direction of the mold). distribution). Therefore, in order to prevent the cooling performance, which is the most important function of the mold, from decreasing, the electromagnetic coil is installed in a lower region where the amount of cooling water required is reduced.

That is, the present invention comprises a spray cooling mold in which the outer surface of the mold for continuous casting equipment is cooled by spray water and the flow rate is distributed in the longitudinal direction of the mold. This is a spray cooling mold for continuous casting equipment equipped with an electromagnetic stirring device, characterized in that an electromagnetic coil for electromagnetic stirring is provided at a portion where a spray nozzle is arranged so that cooling water hits the spray nozzle.

〔Example〕

Hereinafter, the present invention will be explained in detail based on FIGS. 1 and 2. FIG. 1 is a side view including a partial cross section of a spray cooling mold according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line shown in FIG. 1. 1st
In the figures and FIG. 2, the mold 1 is fixed to a cover plate 13 by a keeper plate 12, and a frame 14 is externally installed on the outer periphery of the cover plate 13 via a vibration guide 15. Further, the cover plate 13 is provided with a mechanism for vertically vibrating the mold 1, and this mechanism includes a support pin 18, levers 19, 19',
It consists of a support shaft 20 and a bearing 21.

The frame 14 is a box-shaped container, and is positioned and fixed to fixed frames 22, 22' with bolts 23, 23'. Furthermore, a spray pipe 24 for cooling the surface part of the mold 1 and a spray pipe 25 for cooling the corner are installed inside the mold 1, and the surface cooling spray pipe 24 is attached to the upper part 30 of the length of the mold 1.
~50% and below that, only the corner cooling spray pipe 25 is arranged.

An electromagnetic stirring coil 26 is fixed to the frame 14 in a portion where only corner cooling is performed, facing the mold surface. Mold surface and electromagnetic stirring coil 2
The gap in No. 6 is 10 to 30 mm.

In the cooling mold configured as described above, the cooling water supplied to the spray pipes 24 and 25 is turned into a mist from the nozzles of the spray pipes 24 and 25, and directly cools the mold 1. Furthermore, the lower electromagnetic stirring device 26 rotates the molten steel in the mold 1 to improve the quality of the slab.

〔effect〕

(1) As described in detail above, the present invention uses spray cooling to cool the mold instead of the conventional opposed water flow inside the jacket, so that the electromagnetic stirring coil can be placed at a minimum distance from the mold surface (10 to 30 mm). There is no shield between the mold and the coil, which has the effect of minimizing the attenuation of electromagnetic force.

(2) Since the molten steel in the mold is continuously drawn downward while solidifying, the molten steel and the mold are in contact with each other at the top of the mold, and the heat flow is at its maximum, and as it goes downwards, the contact between the solidified shell and the mold increases. Therefore, the thermal resistance is large and the heat flow is reduced.

If the amount of cooling water is constant as in a conventional mold, the temperature distribution on the mold wall will be as shown by the dotted line in Figure 6B, with a large temperature difference between the maximum and minimum temperature.
Cooling of the slab also becomes more uneven, causing deformation and cracking of the slab.

In order to make the temperature of the mold walls as uniform as possible (that is, to make the heat flow from molten steel to the mold as uniform as possible), it is necessary to vary the cooling capacity in the longitudinal direction of the mold, and this In the case of the spray cooling mold of the invention, the flow rate can be freely distributed in the longitudinal direction of the mold, and the above-mentioned drawbacks of the conventional method can be effectively eliminated.

The mode of distributing the flow rate in the longitudinal direction of the mold is shown in FIG. 6A in comparison with a conventional mold.
The mold wall temperature distribution in this case is shown in FIG. 6B in comparison with a conventional mold. The solid lines in FIGS. 6A and 6B are for the present invention, and the dotted lines are for the conventional case.

[Brief explanation of the drawing]

FIG. 1 is a side view including a partial cross section of a spray cooling mold according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line shown in FIG. 1. FIG. 3 is a plan view of a conventional cooling mold, FIG. 4 is a side view including a partial cross section of the mold, and FIG. 5 is a view taken along the arrows including a partial cross section of FIG. FIGS. 6A and 6B are charts showing the effects of the present invention. 1... Mold, 2... Water channel, 3... Cooling water chamber, 3a... Jacket, 3b, 3c... Partition wall,
4...Magnetic stirring coil, 5...Cooling water piping, 1
2...Keeper plate, 13...Cover plate, 14...Frame, 15...Vibration guide, 1
8...Support pin, 19, 19'...Lever, 2
0... Support shaft, 21... Bearing, 22, 22'...
Fixed frame, 23, 23'... Bolt, 24, 25...
...Spray tube, 26...Magnetic stirring coil.

Claims (1)

[Claims] 1 Consists of a spray cooling mold in which the outer surface of the mold for continuous casting equipment is cooled by spray water and the flow rate is distributed in the longitudinal direction of the mold,
A spray cooling mold for continuous casting equipment equipped with an electromagnetic stirring device, characterized in that an electromagnetic coil for electromagnetic stirring is provided in the lower part of the mold where a spray nozzle is arranged so that cooling water hits the corner of the mold. .