JPH0663704A - Continuous casting equipment with seal device - Google Patents

Abstract

PURPOSE:To prevent the invasion of air into a molten metal pouring basin from a gap by surely sealing the gap between both end parts of a molten metal surface protecting cover and the outer peripheral surface of each roll with a seal plate and to remove even a small quantity of the air stuck to the outer peripheral surface of the roll by sucking the air between the seal plate and the outer peripheral surface of the roll with a vacuum pump. CONSTITUTION:The molten metal surface protecting cover 7 is provided the molten metal pouring basin 3 formed between one pair of the mold rolls 1A, 1B, and the seal plate 24 being in freely sliding contact with the outer peripheral surface of each roll 1A, 1B is successively provided from both end parts of the molten metal surface protecting cover 7 to the reverse rotating directional side of the rolls 1A, 1B, and a vacuum pump 34 for sucking the air between the seal plate 24 and the outer peripheral surfaces of the rolls 1A, 1B is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a twin roll type continuous casting facility in which a sealing device for preventing oxidation is provided at a winding portion between a molten metal surface and a mold roll.

[0002]

2. Description of the Related Art Conventionally, as this type of continuous casting equipment,
There is one described in JP-A-2-220740. That is, a heat insulating material (metal surface protection cover) is provided in a molten metal reservoir formed between a pair of mold rolls, and the heat insulating material is floated on the molten metal surface, and the heat insulating material is removed from both edges parallel to the mold roll. A dipping wall portion is provided so as to project downward and substantially parallel to the surface of the mold roll.

A predetermined gap is secured between both ends of the heat insulating material and the surface of the mold roll, thereby preventing both ends of the heat insulating material from slidingly contacting the surface of the mold roll and being worn. . Further, an inert gas supply pipe for blowing an inert gas is arranged in the gap.

According to this, by covering the surface of the molten metal with the heat insulating material, it is possible to prevent the surface of the molten metal from being oxidized and the temperature from decreasing. Also,
By blowing inert gas from the inert gas supply pipe to the gap between the both ends of the heat insulating material and the mold roll surface, it was prevented that air was entrained in the molten metal from this gap and the molten metal surface was oxidized. .

[0005]

However, according to the above-mentioned conventional type, it is not possible to sufficiently seal the air adhering to the surface of the mold roll simply by blowing the inert gas from the inert gas supply pipe, and the mold roll is not easily sealed. The air adhering to the surface penetrates into the molten metal reservoir through the above-mentioned gap, causing a problem of oxidizing the molten metal surface in the mold roll winding part.

The present invention solves the above problems, and an object of the present invention is to provide a continuous casting facility with a sealing device capable of reliably sealing the gap between the molten metal surface protection cover and the mold roll surface.

[0007]

In order to solve the above-mentioned problems, a continuous casting facility with a sealing device according to the present invention has a metal surface formed in a molten metal reservoir formed between a pair of mold rolls arranged in parallel with each other. A protective cover for the molten metal is provided, and seal plates slidably contacting the outer peripheral surface of the mold roll are continuously provided from both ends of the molten metal protective cover that are parallel to the mold roll to the opposite rotation side of the mold roll. A suction device for sucking air between the plate and the outer peripheral surface of the mold roll is provided.

[0008]

According to the above construction, the gap between the both end portions of the molten metal surface protection cover and the outer peripheral surface of each mold roll is reliably sealed by the seal plates, so that the atmosphere (air) enters the molten metal reservoir through this gap. Can be prevented. Further, by sucking air between the seal plate and the outer peripheral surface of the mold roll by the suction device, it is possible to remove even a small amount of air attached to the outer peripheral surface of the mold roll.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIG. 1 and FIG. 2, 1A and 1B are mold rolls (an example of a moving mold wall) that are arranged in parallel with each other, and are slidably arranged on both end faces of both mold rolls 1A and 1B and both mold rolls 1A and 1B. A molten metal reservoir 3 is formed with the short side weir 2, and is configured to continuously pull out the thin plate cast piece 4 from between the mold rolls 1A and 1B by rotating both mold rolls 1A and 1B in the direction of arrow A. ing. One of the mold rolls 1A and 1B is fixed to the fixed-side mold roll 1A arranged between the pair of fixed roll frames 5A in the width direction, and the other is arranged between the pair of movable roll frames 5B in the width direction. In the movable mold roll 1B, the movable mold roll 1B is moved toward and away from the fixed mold roll 1A by the roll gap control device during slab thickness control and start control.

Reference numeral 7 denotes a molten metal surface protection cover which is arranged so as to cover the molten metal surface 8 in the molten metal reservoir 3 and which prevents heat radiation and oxidation of the molten metal.
The fixed side cover body 7A supported by the bearing body 9 of the fixed side mold roll 1A via the support member 10 and the movable side cover body 7B supported by the bearing body 9 of the movable side mold roll 1B via the support member 10. And a central portion cover body 7 for heat retention, which is slidably arranged in the moving direction of the movable mold roll 1B between the fixed side cover body 7A and the movable side cover body 7B.
It is composed of C and.

As shown in FIG. 3, the fixed side cover body 7A and the movable side cover body 7B are symmetrical to each other, and the inclined lower surface is formed substantially parallel to the mold rolls 1A and 1B so that the width direction of the mold rolls 1A and 1B can be reduced. A heat-resistant fire-resistant aggregate 11 arranged over the surface, a ceramic-coated wool material 12 provided on the surface of the immersed portion of the fire-resistant aggregate 11 for preventing the melt-in into the molten metal, and a central cover body 7C. It is composed of a step portion 13 protruding from the inner surface of the refractory aggregate 11 for supporting. The lower part of the refractory aggregate 11 to which the ceramic coating wool material 12 is attached is configured to be a dipping wall portion 14 which projects below the molten metal surface 8 and is dipped in the molten metal.
A gap D is formed between the immersion wall portion 14 and the mold rolls 1A and 1B.

The central cover body 7C is a cover body 7
Movement of the movable cover body 7B along with the approaching / separating movement of the movable mold roll 1B in the form of a board that is slidably and detachably mounted on the step portion 13 of A and 7B in the moving direction of the movable mold roll 1B. By sliding on the stepped portion 13 to move the molten metal surface protection cover 7 to the movable mold roll 1B.
It is configured so that it can be expanded and contracted in the moving direction to absorb, and the pouring nozzle 15 penetrates at a predetermined position.

As shown in FIGS. 2 and 3, the support member 10
Is a support post 19 erected on the bearing body 9 of the mold rolls 1A and 1B, and a horizontal support member suspended from the upper end of the support post 19 to above the mold rolls 1A and 1B.
It is formed by a horizontal connecting member 20 and an inclined connecting plate 21 extending from the horizontal supporting member 20 toward the molten metal reservoir 3 side and connected to the refractory aggregate 11.

As shown in FIG. 1, both mold rolls 1
Each of A and 1B is provided with a seal plate 24 which is slidable along the outer peripheral surface in the width direction. The seal plate 24 is a thin plate of carbon steel or stainless steel having a thickness of about 0.01 to 0.2 mm. As shown in FIG. 3, each sealing plate
One end of 24 is connected to the lower end of a bracket 26 via a machine screw 25. This bracket 26 has bolts and nuts 27.
It is attached to the horizontal support member 20 via. At this time, as shown in FIG. 4, both side ends of one end portion of each seal plate 24 are pressed against the inner side surface of the short side dam 2 and are in close contact with both side end surfaces of the mold rolls 1A and 1B. The other end of each seal plate 24 is connected to each mold roll 1A,
Each roll frame 5 is continuously provided on the side opposite to the rotation direction of 1B.
Bracket 28 spanning the width between A and 5B
(See FIG. 1). As shown in FIG. 3, a ceramic wool material 29 for sealing is inserted in the space between the bracket 26 and the refractory aggregate 11.

An inert gas supply pipe 40 is connected to the bracket 26 via a boss portion, and the inert gas (nitrogen gas, argon gas, etc.) is protected from the inert gas supply pipe 40 by the molten metal surface. Both ends of the cover 7 and each mold roll 1
It is sprayed into the gap 47 between the outer peripheral surfaces of A and 1B.

As shown in FIG. 1, a suction device 30 for sucking air between the seal plate 24 and the outer peripheral surfaces of the mold rolls 1A and 1B is provided at an intermediate portion in the length direction of the seal plate 24.
Is provided. That is, the suction device 30 is formed by a suction box 32 having a suction space 31 inside, a suction pipe 33 communicating with the suction space 31, and a vacuum pump 34 connected to the suction pipe 33.

That is, as shown in FIGS. 5 and 6, the suction box 32 has a gate-shaped cross-section with the lower surface and both side surfaces open, and is provided on the seal plate 24 side in the width direction. . The seal plate 24 is divided in the suction space 31 and bent upward, and a small screw 35 is attached to the inner surface of the suction box 32.
Are connected via. In addition, at both ends of the suction box 32, blocking plates 36 that block both sides of the suction space 31 are provided as pressing plates 37.
And are fixed by pressing with bolts 38. The lower portions of the closing plates 36 are in sliding contact with both end surfaces of the mold rolls 1A and 1B. The suction pipe 33 is connected to the upper surface of the suction box 32 and communicates with the suction space 31. A vacuum pump 34 is connected in the middle of the suction pipe 33. In addition, 39 is a filter.

Further, as shown in FIGS. 5 and 7, both side ends of each seal plate 24 are formed by the leaf springs 42 in each mold roll 1.
It is securely pressed against the outer peripheral surfaces of A and 1B. These leaf springs 42 are attached to an arc-shaped mounting bracket 43 provided along both outer sides of each mold roll 1A, 1B, and a machine screw 44.
Is installed through. These mounting brackets 43 are connected to the roll frames 5A and 5B via connecting posts 45.

As shown in FIG. 1, immediately before the other end of each seal plate 24, a swingable brush 46 that comes into contact with the outer peripheral surface of each mold roll 1A, 1B across the width is attached to each roll frame 5A. , 5B side.

The operation of the above structure will be described below.
Even if the movable mold roll 1B moves toward and away from the fixed mold roll 1A during slab thickness control and start control, the central cover 7C slides on the step 13 to protect the molten metal surface. The cover 7 expands and contracts in the moving direction of the movable mold roll 1B and absorbs it.
Therefore, the gap D between the mold rolls 1A and 1B does not change. Therefore, it is possible to prevent deterioration of the properties of the slab due to the variation of the gap D.

Further, an inert gas is blown from the inert gas supply pipe 40 into a gap 47 between both end portions of the molten metal surface protection cover 7 and outer peripheral surfaces of the mold rolls 1A and 1B, and the gap 47 is sealed by the seal plate 24. Because it is sealed securely by
Atmosphere (air) can be sufficiently prevented from entering the molten metal reservoir 3 through the gap 47, and oxidation of the molten metal surface 8 can be reliably prevented.

At this time, by using carbon steel or stainless steel for the seal plate 24, it is possible to withstand a high temperature of 500 ° C.,
Moreover, it exhibits excellent properties against sliding wear with the mold rolls 1A and 1B. In addition, the seal plate 24 has a thickness of 0.01 to
By forming a thin plate of 0.2 mm, the sealing plate 24
Has excellent flexibility, and each mold roll 1A, 1B
Make sure sliding contact along the deformed shape of the outer peripheral surface.

Further, by sucking the air between the seal plate 24 and the outer peripheral surfaces of the mold rolls 1A and 1B by the suction device 30, even a small amount of air attached to the outer peripheral surfaces of the mold rolls 1A and 1B is removed. You can At the same time, a negative pressure is applied between the inside of the suction space 31 of the suction box 32 and between the seal plate 24 and the outer peripheral surfaces of the mold rolls 1A and 1B, so that the degree of close contact between the seal plate 24 and the outer peripheral surfaces of the mold rolls 1A and 1B. And the airtightness is improved. The air sucked by the suction device 30 is discharged from the vacuum pump 34.

Further, since the suction by the vacuum pump 34 sucks out the inert gas from the molten metal surface 8 side to the suction space 31 side, the seal plate 24 and the mold rolls 1A, 1B should be sucked.
Even if a small amount of air enters between the outer peripheral surface and the outer peripheral surface, the air is mixed with the inert gas sucked to the suction space 31 side and diluted and discharged. In this way, the inert gas is added to the surface 8
When sucked from the side to the suction space 31 side, the air diluted with the inert gas in the suction space 31 is prevented from further entering the molten metal surface 8 side.

Further, as shown in FIG. 1, since the brush 46 scrapes off the dust attached to the outer peripheral surfaces of the mold rolls 1A and 1B, the air attached to the dust is also removed by the brush 46. This prevents air from entering the molten metal surface 8 side while adhering to the outer peripheral surfaces of the mold rolls 1A and 1B together with dust.

FIG. 8 is a graph of oxygen concentration in the above embodiment, and FIG. 9 is a graph of oxygen concentration in the conventional example. As shown in FIG. 3, the oxygen concentration in each of the above-described embodiments is the same as that of each end of the melt level protection cover 7 and each mold roll 1.
The concentration in the gap 47 between the outer peripheral surfaces of A and 1B is shown and measured by an oxygen concentration meter 48. The oxygen concentration in the conventional example is also the concentration at the same position as above.

According to this, as shown in FIG. 8, in the embodiment, the oxygen concentration after the start of casting decreased and was stable at about 2%, but in the conventional example, it decreased to about 5% as shown in FIG. However, it is unstable. This is because the air adhering to the roll surface cannot be sufficiently sealed only by spraying the inert gas in the conventional example.

[0028]

As described above, according to the present invention, the gap between the both end portions of the molten metal surface protection cover and the outer peripheral surface of each mold roll is reliably sealed by the seal plates. Atmosphere (air) can be prevented from entering. Further, by sucking air between the seal plate and the outer peripheral surface of the mold roll by the suction device, it is possible to remove even a small amount of air attached to the outer peripheral surface of the mold roll. Therefore, it is possible to reliably prevent oxidation of the molten metal surface at the winding portion of each mold roll. As a result, it is possible to prevent uneven heat transfer due to oxides and deterioration of the quality of the slab.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view of a twin roll type continuous casting facility with a sealing device according to an embodiment of the present invention.

FIG. 2 is a vertical sectional front view showing a supporting structure of a molten metal surface protection cover.

FIG. 3 is a detailed view of a connecting portion between the seal plate and the molten metal surface protection cover in FIG.

4 is a view on arrow aa in FIG. 3. FIG.

FIG. 5 is a partially enlarged view of the suction device in FIG.

6 is a view taken along the line bb in FIG.

FIG. 7 is a view on arrow c-c in FIG.

FIG. 8 is an oxygen concentration graph in a gap between both end portions of the molten metal surface protection cover and the outer peripheral surface of the mold roll.

FIG. 9 is an oxygen concentration graph in a gap between both end portions of a molten metal surface protection cover and an outer peripheral surface of a mold roll in a conventional example.

[Explanation of symbols]

 1A Mold roll 1B Mold roll 3 Molten metal reservoir 7 Metal surface protection cover 8 Metal surface 24 Seal plate 30 Suction device

Claims (1)

[Claims] 1. A molten metal reservoir formed between a pair of mold rolls arranged parallel to each other is provided with a molten metal surface protection cover for covering the molten metal surface, and a seal plate slidably contactable with the outer peripheral surface of the mold roll. , A suction device is provided which is continuously provided from both end portions of the melt level protection cover parallel to the mold roll in the direction opposite to the rotation direction of the mold roll and which sucks air between the seal plate and the outer peripheral surface of the mold roll. A continuous casting facility with a characteristic sealing device.