JPH0441049A - Sealing structure around brake ring in horizontal continuous casting apparatus - Google Patents

Abstract

PURPOSE:To prevent deterioration of an annular gasket caused by heat and to hold sealing property by fixing a cooling ring at outer periphery of a feed nozzle and inserting the annular gasket at between the cooling ring and side wall of a mold. CONSTITUTION:As one side of sealing face in the annular gasket 46 is brought into contact with the cooling ring 31 and the other side of sealing face is brought into contact with the side wall 22 face of water cooled mold 21, the annular gasket 46 is held to heat resistant temp. or lower. Therefore, the annular gasket 46 is not deteriorated with heat and the sealing property is not lost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a seal structure around a break ring in a horizontal continuous casting machine.

This invention is utilized for horizontal continuous casting of billets of carbon steel, stainless steel, and other metals.

[Prior Art] Horizontal continuous casting equipment has lower equipment costs, installation area, and operating costs than vertical continuous casting equipment, does not generate stress due to bending of slabs, and has less hull sink. Especially, it is economically efficient for small-capacity casting equipment. I wanted to,
In recent years, horizontal continuous casting equipment has been put into practical use for billet casting.

FIG. 4 shows a vertical cross section of the connecting portion between the tundish 11 and the mold 21 in a boat-type horizontal continuous casting apparatus. As shown in the drawings, in the horizontal continuous casting apparatus, the tundish 11 and the mold 21 are connected through a slitting nozzle 14 and a foot nozzle I6.

The tundish nozzle 11, the sliding nozzle 14, and the feed nozzle 16 are each made of ordinary refractories such as zircon or alumina. The mold 21 is generally made of copper and is cooled by cooling water W, and a flake ring 18 is attached to the entrance side. The break ring 18 is made of heat-resistant ceramics such as boron nitride and silicon nitride. Note that some devices are not equipped with the above-mentioned slitting nozzle 14.

The molten metal M supplied into the mold 21 is cooled by the inner peripheral surface of the mold to form a solidified shell S. Formation of the solidified shell S is started from the break ring 18.

The break ring '18 prevents the solidified shell S from growing in the opposite direction, ie, toward the feed nozzle]6 side. A slab formed by solidifying the molten metal M is intermittently pulled out from the outlet side of the mold 21 by a pulling device (not shown) such as a pinch roll. When the slab is intermittently pulled out, a gap is created between the break ring 18 and the end of the solidified shell S, and new molten metal M flows into the gap.

By the way, since the above-mentioned gap is in a negative pressure state and the mold 21 and the break ring 18 are only fitted together, air enters the gap from between the joint surfaces of the two. The air that has entered is drawn into the molten metal M and remains inside or on the surface of the slab, causing casting defects such as air bubbles (blowholes).

As a solution to such problems, the
There is a "plate ring mounting structure for horizontal continuous casting machine" disclosed in Japanese Patent No. 8136. This break ring mounting structure airtightly seals the joint between the break ring and the molten metal cooling part of the mold using a heat-resistant O-ring. The O-ring is a heat-resistant O-ring made of silicone rubber, and can withstand temperatures of, for example, 250°C. This publication also discloses that the ring-shaped space around the O-ring is filled with a heat-resistant sealing material such as silicone sealant or graphite cement.

[Problems to be Solved by the Invention] In the conventional break ring mounting structure described above, one sealing surface of the O-ring is in direct contact with the break ring. 0
The break ring part where the ring touches is 300 to 400
The temperature is around ℃. FIG. 3(b) shows an example of the temperature distribution near the break ring. Currently, the upper limit of heat resistance temperature of O-rings in practical use is at most 300.
It is about ℃. Therefore, the O-ring deteriorates or burns out due to heat, and cannot maintain airtightness. Also,
Since the heat-resistant O-ring is sandwiched between the break ring and the molten metal cooling part of the mold, there is a risk of damaging the fragile break ring, and it is also difficult to attach the break ring to the mold.

Further, the cement used in combination with the O-ring cannot expand by 1° following the thermal expansion of the mold and break ring, so it is still difficult to maintain airtightness even if cement is used in combination.

Therefore, the present invention seeks to provide a seal structure around the break ring that can reliably maintain airtightness at the joint between the mold and the break ring without causing the O-ring to deteriorate due to heat in a horizontal continuous casting machine. It is.

[Means for Solving the Problems] The seal structure around the break ring of the present invention has a structure in which the tongue tissue and the mold communicate with each other via a feed nozzle,
In a horizontal continuous casting machine in which a break ring is attached to the entrance side of the mold, a hollow cooling ring is fixed to the outer periphery of the feed nozzle, and an O ring is sandwiched between the hollow cooling ring and the side wall of the mold. There is.

The cooling ring is made of metal such as iron or copper alloy. The front surface of the cooling ring (the surface facing the side wall of the mold) is a cooling surface that directly cools the O-ring, and also roughly cools the atmosphere around the O-ring. The inner circumferential surface of the cooling ring serves as an adhesive surface to the feed nozzle, and also cools the outer circumferential portion of the feed nozzle. The cross-sectional size and shape of the cooling ring are not particularly limited, or at least must be such that the O-ring can be maintained at a temperature below the heat-resistant temperature. Note that the O-ring is made of a normal material having appropriate elasticity and heat resistance, such as silicone rubber. Appropriate sealing surface pressure is applied to the O-ring when the mold is connected to the tongue tissue.

An adhesive is used to secure the cooling ring to the outer periphery of the feed nozzle. As the adhesive, a cement material with high adhesive strength and airtightness is suitable, such as Ram 90 (trade name of Nippon Crucible Co., Ltd., an alumina-based cement material).

Note that the cooling capacity of the cooling ring can be increased by providing fins on the heat radiation surface to increase the heat radiation area, or by making the cross section hollow and allowing cooling gas to flow through it for forced cooling.

When cooling gas flows through the hollow cooling ring,
In order to allow the cooling gas to flow through, the inside of the hollow cooling ring is partitioned by partition walls at one or more locations along the circumferential direction.
An inlet and an outlet for the cooling gas may be provided for each partitioned section. Air, nitrogen gas, etc. are suitable as the cooling residue. These cooling wastes are supplied to the hollow cooling ring from a compressor or a pressurized bong.

[Function] Since one sealing surface of the O-ring is in contact with the cooling ring and the other sealing surface is in contact with the side wall surface of the water-cooled mold, the O-ring is maintained at a temperature below the heat-resistant temperature. Therefore, the O-ring does not deteriorate due to heat and does not lose its sealing performance.

[Example] Fig. 1 shows a first example of the present invention using a hollow cooling ring, in which a billet is continuously cast.

Note that members similar to those shown in FIG. 4 described above are given the same reference numerals, and detailed explanation thereof will be omitted.

An iron hollow cooling ring 31 is attached to the outer periphery of the feed nozzle 16.
They are fitted together and bonded with cement material. The hollow cooling ring 31 has a rectangular ring shape as a whole, and has a trapezoidal cross section.

The inside of the hollow cooling ring 31 is partitioned by a partition wall (not shown). Hollow cooling ring 31 is O ring 46
In order to enhance the cooling effect of the mold 21 and its surroundings, a wide surface (front surface) 32 faces the side wall 22 of the mold 21.

The rear side of the hollow cooling ring 31 has a feed nozzle holder 29
is held down by Further, a cooling air supply pipe 43 and a cooling air discharge pipe (not shown) are connected to the hollow cooling ring 31. The cooling air supply pipe 43 is equipped with a cooling device 41 that includes a compressor, a cooler, a dehumidifier, etc.
or connected. The cooling air supplied from the cooling air supply pipe 43 to the hollow cooling ring 31
The air is cooled by going around the inside almost once, and is then released to the atmosphere through a cooling air exhaust pipe.

A shallow groove 24 for positioning the O-ring is provided in the side wall 22 of the mold 21, into which the O-ring 46 is inserted. When connecting the mold 21 to the tongue tissue 11, the O-ring 46 is compressed between the side wall 22 of the mold 21 and the front surface 32 of the hollow cooling ring 31 to provide the required sealing surface pressure.

FIG. 3(a) shows a temperature distribution diagram around the O-ring in the above embodiment. The temperature of the hollow cooling ring is a measured value, and the temperature of the mold is a calculated value. The maximum temperature near the O-ring is around 200°C, which is well below the 270°C heat resistance temperature of the silicone rubber O-ring.

FIG. 2 shows a second embodiment of the invention.

This embodiment differs from the first embodiment in that the cross-sectional shape of the hollow cooling ring is different.

The cross-sectional shape of the hollow cooling ring 35 is L-shaped, and a wide surface (front) 36 faces the side wall 22 of the mold 21. A shallow groove 38 for positioning the O-ring is provided on the outer periphery 37 of the hollow cooling ring 31, and an O-ring 48 is fitted therein. The outer peripheral side of this O-ring 48 is in contact with the mold presser 27. Note that the mold presser 27 fixes the mold 21 to the frame 26. In this embodiment, high airtightness is achieved because the seal is provided by two sets of O-rings 46 and 48.

[Effects of the Invention] In the present invention, since the O-ring and the surrounding cooling ring are used for cooling, the O-ring is maintained at a temperature lower than its heat-resistant temperature and is not deteriorated by heat. Therefore, the joint between the mold and the break ring is kept airtight, and air is prevented from entering the mold from the joint. This prevents casting defects such as air bubbles, thereby improving the quality and yield of the slab, and also making it possible to eliminate scraping work.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, which is a sectional view around the break ring, Fig. 2 shows another embodiment, which is a sectional view around the break ring, and Fig. 3 shows the temperature around the O-ring. An example of the distribution is shown. Figure 3(a) is a temperature distribution diagram in the case of this invention, Figure 3(b) is a temperature distribution diagram in the conventional case, and Figure 4 is a temperature distribution diagram in the case of general horizontal continuous casting. FIG. 3 is a longitudinal cross-sectional view of a connecting portion between a tundish and a mold in the device. 1, 1--Tandish, 14--Sliding nozzle, 16--Feed nozzle, 18--Break ring, 21--Mold, 22--Mold side wall, 31.35--Hollow cooling Ring, 41... Cooling device, 46.48... O ring, M... Molten metal, S
... solidified shell, W... cooling water.

Claims (1)

[Claims] 1. In a horizontal continuous casting machine in which a tundish and a mold are connected via a feed nozzle and a break ring is attached to the entrance side of the mold, a cooling ring is fixed to the outer periphery of the feed nozzle, and the cooling ring and the A seal structure around a break ring in a horizontal continuous casting machine, characterized in that an O-ring is sandwiched between the side wall of a mold.