JPH0137816Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a nozzle receiving eccentric sleeve brick interposed between the nozzle receiving brick and the immersion nozzle of a tundish.

Conventionally, in continuous casting operations in which slabs of different sizes are drawn from multiple strands in the same tundish, for example, two out of four strands are drawn from a small mold 1 and a large mold of different diameters, as shown in Fig. 1. 2, in order to make the subsequent guide rolls support the drawn slab,
The guide roll is installed with its one end surface aligned with the guide roll reference line 3 aligned with the outer ring side of the curved part of the guide roll. For this purpose, the guide roll reference line 3 of the small mold 1 and large mold 2, each having a different diameter, is
Center lines a and b parallel to each other have an eccentricity of width A. If this eccentricity is ignored and the immersion nozzle is set to match the center of one of the molds, if the immersion nozzle is immersed without aligning with the center, the inner wall of the mold on the side where the immersion nozzle is offset Compared to other inner wall surfaces, the inner wall receives more heat load from the molten steel being poured, and its temperature becomes higher. Therefore, thermal stress is generated in the surface solidified layer of the slab that is pulled out of the mold, causing cracks to occur in the surface solidified layer, which is one of the causes of the breakout phenomenon in which unsolidified molten steel inside is spouted out.

Additionally, the flow of molten steel in the mold is disturbed, causing non-metallic inclusions floating near the mold surface to flow deep into the mold and into the slab, resulting in deterioration of the quality of the slab. I will invite you.

In order to prevent such inconvenience, the eccentric width dimension A of the small mold 1 and the large mold 2 is adjusted by making the immersion nozzle insertion hole of the nozzle receiving brick of the tundish eccentric. For this reason, two types of nozzle receiving bricks are required, which increases costs due to the increased number of shapes.If there is a sudden change in the production plan during operation, not only the nozzle receiving brick but also the surrounding bricks must be dismantled. Otherwise, the replacement work cannot be done, the work takes a long time, and the workers end up harming their health due to hard work in a bad environment.

The present invention solves these problems by using a nozzle receiving eccentric sleeve brick interposed between the nozzle receiving brick and the immersion nozzle in order to easily and continuously cast slabs of different molds in multiple strands of the same tundish. The purpose is to provide.

Next, the present invention will be explained in detail based on the drawings. As shown in FIGS. 2 and 3, there is an inner peripheral surface 6 into which the immersion nozzle 4 is fitted, and a nozzle receiving brick 8.
The nozzle receiving eccentric sleeve brick 5 (hereinafter simply referred to as eccentric sleeve 5) of the tundish 21 has an outer circumferential surface 7 that fits into the tundish 21 and is eccentric by a required dimension.

An example in which the eccentric sleeve 5 thus constructed is applied to a four-strand tundish shown in FIG. 1 for continuous billet casting will be described below.

Two types, small mold 1 with slab size 170 mmφ and large mold 2 with 230 mmφ, are placed in the same tundish.
When pulling out two strands at a time,
The eccentric width dimension A is 30 mm, and the inner circumferential surface 6 and outer circumferential surface 7 of the eccentric sleeve 5 used at a position rotated by 180 degrees.
The eccentric width dimension of is 15mm at 1/2A.

In Fig. 4, the eccentric sleeve 5 is fitted into the nozzle receiving brick 8, and the eccentric width dimension of the strand is A=30.
Place the nozzle receiving brick 8 on the center line (1/2) C of mm.
Align the center line d of the eccentric sleeve 5, install it on the tundish 21, and place it on the guide roll reference line 3 side from the center line d of the eccentric sleeve 5 to 1/2A=15
An eccentric sleeve 5 is shown in which the immersion nozzle 4 is inserted into the inner circumferential surface 6 which is offset by mm, and the centerline e of the immersion nozzle 4 is set to align with the centerline a of a small mold 1 having a slab size of 170 mmφ.

In Fig. 5, the eccentric sleeve 5 is rotated 180 degrees and the immersion nozzle 4 is placed on the opposite side of the guide roll reference line 3 from the center line d of the nozzle receiving brick 8 by 1/2A = 15mm.
The eccentric sleeve 5 is shown eccentrically set so that the center line e of the immersion nozzle 4 is aligned with the center line b of a large mold 2 having a slab size of 230 mmφ. It goes without saying that the centers of the small mold 1 and large mold 2 of each strand and the centers of the immersion nozzle 4 in the direction perpendicular to the guide roll reference line 3 coincide with each other. The 180° rotational position of the eccentric sleeve 5 is confirmed by aligning the notch marks 9 of the eccentric sleeve 5 and the nozzle receiving brick 8. This cutout mark 9 is covered and protected by a tundish board 11 that protects the tundish lining brick 10, so that it will not disappear due to wear and tear.

In addition, even if there is a sudden change in the production plan during operation, simply remove the eccentric sleeve 5 and replace it.
The slab size can be easily changed.

In the embodiment, a four-strand tundish was described as an example, but the present invention is not limited to this, and the present invention can be used in a plural-strand tundish, and the eccentric dimension can be arbitrarily determined as required.

As explained above, the present invention prevents the nozzle receiving brick from becoming multi-shaped by combining slabs of different molds into multiple strands of the same tundish, and can quickly respond to sudden changes in the production plan during operation.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the strand of the tundish, Fig. 2 is a perspective view of the nozzle receiving eccentric sleeve of the present invention, Fig. 3 is a sectional view of the spout of the tundish, and Figs. 4 and 5 are the nozzle receiving eccentric sleeve. Eccentricity explanatory diagram. In the figure, 4... Immersion nozzle, 5... Nozzle receiving eccentric sleeve brick, 6... Inner peripheral surface, 7... Outer peripheral surface, 8... Nozzle receiving brick.

Claims (1)

[Scope of utility model registration request] This nozzle receiving eccentric sleeve brick for a tundish has an inner circumferential surface 6 into which an immersion nozzle 4 is fitted and an outer circumferential surface 7 into which a nozzle receiving brick 8 is fitted are eccentric by a required dimension.