JPH03248753A - Cooling device in continuous casting machine - Google Patents

Abstract

PURPOSE:To improve the productivity of continuous casting machine by forming cooling water passage with plural guide rolls, sealing device among them and a cast slab and forcedly flowing the cooling water crossing at the right angle to shifting direction of the cast slab in there. CONSTITUTION:The cast slab 1 is guided with plural guide rolls 2 arranged as mutually facing just below the mold 4. Gaps among the guide rolls 2 are sealed with a jacket 5 in the sealing device. The cooling water passage 6 is formed with the guide rolls 2, jacket 5 in the sealing device and the cast slab 1. The cooling water forcedly flowed in the direction at the right angle to the shifting direction of cast slab 1 in the cooling water passage 6, is flowed. The sealing is made with the sealing rolls arranged while contacting with the guide rolls at between the guide rolls. By this method, this can eliminate any fear, which develops bulging and breakout with molten metal at unsolidified layer in the cast slab.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cooling device for a continuous casting machine.

[Conventional technology and its issues]

Recently, there has been a trend to increase the casting speed in order to improve productivity in continuous casting machines. However, when the casting speed is increased, the growth of the shell on the surface of the slab cannot keep up and the shell thickness becomes thinner, resulting in a higher incidence of flake-out. Therefore, in order to promote cooling in the secondary cooling zone and prevent the occurrence of breakout, improvements to spray devices, cling plates, cooling grids, and the like have been proposed.

For example, according to Japanese Patent Application Laid-open No. 62-227562, in order to rapidly and uniformly cool the slab while avoiding the abrasion of the cooling plate and cooling grid mentioned above, the slab is sandwiched directly under the mold. An ice chamber with many slits is installed in the wall on one side of the casting, and pressurized water is spouted from these slits to form a water bed between the slab and the ice chamber, avoiding direct contact between the ice chamber and the slab. Proposals have been made to cool slabs rapidly and uniformly.

Furthermore, according to Japanese Patent Application Laid-Open No. 55-84257, a continuous casting method is disclosed in which a slab being continuously cast directly below the mold of a continuous casting machine is surrounded and cooled by a cooling water pool provided with a variable pressure. is proposed.

However, in the secondary cooling devices proposed in these proposals, the slab is not forcibly supported by guide rollers, etc., so bulging caused by molten metal from the unsolidified layer, which is particularly likely to occur in wide slabs, can be avoided. Moreover, since the direction of flow (movement) of the cooling water is the same as or opposite to the direction of movement of the slab, uneven cooling tends to occur in the width direction of the slab, and the unsolidified layer inside the slab is likely to occur. Since the static (iron) pressure from the steel is compensated (supported) by pressurized cooling water, it is difficult to control the pressure, and the reliability of suppressing bulging and preventing breakout is also low.

[Means to solve the problem]

Therefore, the present invention was created in order to solve the problems of the conventional example, and its gist is that in a cooling device of a continuous casting machine, slabs placed directly below the mold and facing each other are guided. a plurality of guide rolls; a sealing device that seals the guide rolls to each other;
The present invention provides a cooling device for a continuous casting machine, characterized in that a cooling water passage is formed by the slab, and cooling water that is forced to flow in a direction perpendicular to the direction of movement of the slab is passed through the cooling water passage.

〔Example〕

The structure of the present invention will be described in detail with reference to embodiments shown in the accompanying drawings.

FIG. 1 is a sectional view showing a first embodiment of the present invention, and FIG. 2 is a perspective sectional view of a main part of the second embodiment.

In FIG. 1, the molten steel injected into the mold 4 is indirectly cooled primarily and is continuously pulled out from the bottom of the mold 4 as a slab 1, but the slab 1 at this time has a shell layer 1a on the surface. It is formed by an internal unsolidified layer 1b. The slab 1 is then directly cooled by the following forced cooling device.

That is, this forced cooling device covers a plurality of guide rolls 2.2... groups consisting of free rollers arranged opposite to each other directly below the mold 4, and the backs and upper and lower ends of these guide rolls 2. and a jacket 5 extending toward the slab 1 so as to coincide with a line connecting substantially central axes of vertically adjacent guide rolls 2, and the jacket 5 and the guide rolls 2, 2, 2... A cooling water passage 6 is formed by the group and the slab 1.

Both ends of this cooling water passage 6 are communicated with a cooling water cane/discharge jacket (not shown) provided on a short side surface (thickness direction surface) of the slab 1.

Therefore, the slab 1 has a plurality of guide rolls 2゜2...
They are supported in groups and are directly cooled by the cooling water that forcibly flows through the cooling water passage 6 substantially perpendicular to the drawing direction of the slab 1, so that they are rapidly cooled while retaining their shape.

The upper end 5a and the lower end 5b of the jacket 5 in the direction of slab movement are formed of a flexible heat-resistant material, and the jacket 5 is made of a flexible heat-resistant material so that the slab 1 is constantly
The cooling water retention capacity is increased by sliding contact with the surface of the cooling water.

Further, the cooling capacity of the cooling water can be easily controlled by adjusting the amount of cooling water flowing through the cooling water passage 6.

When the cooling rate of the cooling device was measured, it was found that heat could be removed approximately five times faster than the conventional spray type. In FIG. 3, 3 is a guide roll following the group of guide rolls 22.

Note that it is desirable to thermally balance the direction of the water flow flowing through the cooling water passages 6 so that the water flow directions of adjacent cooling water passages 6 are opposite (i in FIG. 2 is water supply, 0
indicates drainage (see this), and if a boiling film is formed on the surface of the slab 1, the heat removal effect will be reduced due to the heat insulation effect of this boiling film, so take precautions to prevent the formation of a boiling film. A sufficient amount of water is forced to flow. Moreover, the water pressure is set to be lower than the static iron pressure from the unsolidified molten steel 1b to maintain contact between the guide rolls 2 and the slab 1 and to provide good support.

Next, a second embodiment of the present invention will be described. Since the second embodiment is basically the same as the first embodiment, only the differences will be explained.

In the second embodiment shown in FIG. 2, instead of the jacket 5 of the first embodiment, a small diameter sill roll 2a is provided between the guide rolls 2, 2... which are vertically adjacent to each other in the group. , this sealing roll 2a and guide rolls 2, 2...
- A cooling water passage 6 is formed by the group and the slab 1.

Note that although the present invention is particularly effective for continuous casting machines for wide slabs, it goes without saying that it can also be applied to continuous casting machines for billlefts and blooms.

〔Effect of the invention〕

According to the present invention, a cooling water passage is formed by a plurality of guide rolls, a sealing device that mutually seals between the guide rolls, and the slab 1, and the cooling water passage is forced in the width direction of the slab. Since the slab is directly cooled by the flowing cooling water,
The slab can be cooled uniformly and quickly in the width direction. Furthermore, since the slab is supported by guide rolls and pulled out, there is no fear that the slab will cause bulging or breakout due to the molten metal in the unsolidified layer. Therefore, the productivity of the continuous casting machine can be further improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a second embodiment of the present invention.
FIG. 2 is a perspective sectional view of a main part of the embodiment. DESCRIPTION OF SYMBOLS 1... Slab, 2... Guide roll, 2a... Sealing roll, 5... Jacket, 6... Cooling water passage. Sub-Agent Patent Attorney Yoshihiko Okabe

Claims (3)

[Claims] (1) In a cooling device for a continuous casting machine, the slab is cooled by a plurality of guide rolls that are provided directly under the mold and facing each other to guide the slab, a sealing device that seals between the guide rolls, and the slab. form a water passage,
A cooling device for a continuous casting machine, characterized in that cooling water is forced to flow in a direction perpendicular to a direction of movement of slabs in the cooling water passage. (2) The cooling device for a continuous casting machine according to claim 1, wherein the sealing device is a jacket arranged to seal between the guide rolls. (3) The cooling device for a continuous casting machine according to claim (1), wherein the sealing device is a sealing roll provided between and in contact with the guide rolls.