JPH0957430A - Sliding nozzle device having surface pressure loading body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save the cost of a plate refractory by shortening the length of an upper plate used to a sliding nozzle device. SOLUTION: When using D for hole diameter of nozzle holes 5A, 6A arranged at the upper plate 5 and a lower plate 6, respectively, S for a sliding stroke of the lower plate 6 and L for surface pressure loading range in the length direction of the plate while centering the nozzle hole 5A of the fixed slide upper plate 5, the surface pressure force is given from the upper and the lower parts of the mating surface of the upper plate 5 and lower plate 6 under condition of 1.5 D<=L<=S. By this constitution, the plate length of the upper plate 5 is shortened and the surface pressure is loaded with an elastic body, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding nozzle device having a surface pressure load body suitable for controlling the outflow amount of molten steel from a molten metal container such as a ladle containing molten steel or a tundish. .

[0002]

2. Description of the Related Art In continuous casting, molten steel is poured into a tundish by using a sliding nozzle device provided at the bottom of a molten steel ladle, and further controlled by a sliding nozzle device provided at the bottom of the tundish. Is being cast. In the case of a two-layer sliding nozzle device used for a molten metal container such as a ladle and a tundish, as shown in FIG. 4, a sled refractory 3 constructed on the upper surface of an iron shell 2 constituting the molten metal container 1 is used. An upper nozzle 4 is provided, and a fixed side upper plate 5 is provided so as to be connected to a lower portion of the upper nozzle 4, and the upper plate 5 is further provided.
The lower plate 6 on the sliding side is arranged so as to be slidable in the horizontal direction by contacting the lower surface of the.

To inject the molten metal 7 accumulated in the molten metal container 1, the lower plate 6 is slid horizontally with respect to the upper plate 5, and the lower plate 6 is positioned at the nozzle hole 5A provided in the upper plate 5. This is performed by moving the provided nozzle hole 6A. At this time, by adjusting the overlap between the nozzle hole 5A and the nozzle hole 6A, the amount of molten metal injected through the upper nozzle 4 provided in the molten metal container 1 is controlled, and when the two match, the injection amount is It will be the maximum. When the injection of the molten metal 7 is stopped, the lower plate 6 is slid in the nozzle-free portion with respect to the nozzle hole 5A provided in the upper plate 5.

In the sliding nozzle device, a refractory material is used in a portion which is directly exposed to the molten metal 7 such as molten steel.
Both the upper plate 5 and the lower plate 6 are made of refractory material. As shown in FIG. 5, a constant pressure is applied to the mating surfaces of the refractory upper plate 5 and the lower plate 6 from above and below in order to prevent leakage of the molten metal 7. As means for applying pressure to the mating surface between the upper plate and the lower plate of the sliding nozzle device, a nut for pressing the spring is tightened by a torque notch, or pressure is applied by a lever link mechanism via the spring. Further, there is known a means for applying a certain pressure from the lower part of the plate by a pressing machine via a spring.

Further, Japanese Utility Model Laid-Open No. 55-103058 discloses a sliding nozzle device having a pressurizing device for applying surface pressure to the upper plate 5 and the lower plate 6 as shown in FIG. . In FIG. 7, the lower plate 6 on the sliding side is opened and closed using the drive cylinder 21 with respect to the upper plate 5 on the fixed side arranged at the bottom of the molten metal container 1. A lower metal frame 24 is disposed below the support plate 22 slidably supporting the lower plate 6 via a plurality of springs 23.

One end of the lower metal frame 24 is rotatably supported by a bearing 30 attached to the lower surface of the iron shell 2 via a pin 31. Further, in the operating cylinder 32 attached to the iron shell 2 of the molten metal container 1, the pushing-up member 34 supports the other end of the lower metal frame 24 via the two lever link mechanisms 33. Therefore, when the operating cylinder 32 is operated and the push-up member 34 is rotated through the lever link mechanism 33 with the pin 35 as a fulcrum, the push-up member 34 pushes up the other end of the lower metal frame 24. As a result, the spring 23 is caused by the lever action of the lower metal frame 24 with the pin 31 as a fulcrum
It is possible to apply a certain amount of surface pressure to the mating surfaces of the lower plate 6 and the upper plate 5 via.

By the way, the upper plate 5 and the lower plate 6 made of refractory are rapidly worn while being in direct contact with the high temperature molten metal, so that they are worn out significantly and must be replaced in a short time. This raises the cost of refractories, which is a big problem. The use of the upper plate 5 and the lower plate 6 limits the life of the plate because the plate diameter of each plate 5 and 6 is enlarged by melting damage of the nozzle holes 5A and 6A and the plate slides for each charge by sliding the plate mating surface. This means that a certain amount of surface roughness is generated in the direction and wear is caused.

Conventionally, when the upper nozzle and the lower nozzle of the sliding nozzle device are melted in the nozzle hole or the surface of the plate is roughened, it is possible to quickly control the injection amount of the molten metal without any trouble. It is necessary to replace the entire upper and lower plates, which increases the cost of the plate unit. Although various proposals have been made such as selecting and improving the plate material as a measure to extend the life of the upper plate and the lower plate of the sliding nozzle device, it does not lead to a significant extension of the life and the cost of the plate refractory is reduced. Is a major cause of hindrance.

[0009]

As described above, the life of the upper plate and the lower plate of the sliding nozzle device is limited by the melting loss of the nozzle holes locally generated in the upper plate and the lower plate. The surface of the plate is rough. By the way, of the upper and lower plates,
As shown in FIGS. 6 (A) and 6 (B), the plate length actually required for controlling the flow rate of the molten metal is as shown in FIGS. 6 (A) and 6 (B). It is only the length considering the length of. Similarly, with respect to the lower plate 6, it is sufficient if the nozzle holes 5A and 6A can be fully opened and fully closed in consideration of the melt damage of the nozzle holes 6A and the length of the surface roughness. Therefore, in particular, the length of the upper plate 5 should be able to be made significantly shorter than the length of the lower plate 6.

However, when this is used as it is as the length shape of the upper plate 5 and the lower plate 6, as described above, the lower plate 6 has a sliding length for fully opening-closing the nozzle hole 5A of the upper plate 5. Since the space is required, the lower plate 6 has to be longer than the upper plate 5. However, since surface pressure is applied to the upper plate 5 and the lower plate 6 from the upper and lower sides over the entire length, when the nozzle hole is fully opened, as shown in FIG. A large bending stress is applied in the direction. Further, when the nozzle hole is fully closed, as shown in FIG. 6 (B), bending stress is applied to the lower plate 6 from the point C in the arrow direction, and the bending stress causes the lower plate 6 to deform and break. There is a risk.

The present invention has been made in view of the above circumstances, and provides a sliding nozzle device having a surface pressure load body capable of reducing the range in which the surface pressure is applied to the upper plate and the lower plate. The purpose is.

[0012]

In order to achieve the above object, the present invention according to claim 1 is mounted on a bottom portion of a molten metal container, and slides a lower plate on a sliding side with respect to an upper plate on a fixed side. In a sliding nozzle device in which the outflow amount of molten metal is controlled by moving the nozzle holes provided in the upper plate and the lower plate, the hole diameter is D, the sliding stroke of the lower plate is S, and the nozzle hole of the upper plate is centered. When the surface pressure load range in the plate length direction is L, 1.5D
A sliding nozzle device having a surface pressure load body, wherein a surface pressure load body that applies a surface pressure from above and below is provided on a mating surface of an upper plate and a lower plate under a length condition of ≤L≤S. .

According to the present invention of claim 2, the upper plate comprises:
2. The length in the longitudinal direction is shortened to a necessary minimum based on the melting loss of the nozzle hole diameter and the length of surface roughness.
It is a sliding nozzle device having the described surface pressure load body. According to a third aspect of the present invention, a sliding nozzle device having a surface pressure load body according to the first or second aspect is provided with a support guide that guides the lower plate in a range in which the lower plate slides. Is.

[0014]

In the present invention, as shown in (A) fully closed and (B) fully opened in FIG. 3, the nozzle hole 5A provided in the upper plate 5 has a hole diameter D, and the lower plate from fully closed to fully opened. Assuming that the sliding stroke is S and the surface pressure load range in the plate longitudinal direction centering on the nozzle hole 6A of the lower plate 6 is L, the upper plate 5 and the lower plate 6 are A surface pressure load body that applies a surface pressure to the mating surface from above and below is provided.

Here, if the surface pressure load range L <1.5D,
Since the surface pressure load range of the upper plate 5 and the lower plate 6 is too small, the original purpose of preventing the leakage of the molten metal cannot be sufficiently fulfilled. Therefore, it is necessary to set 1.5D ≦ L. Further, it seems that the leakage of the molten metal can be more surely prevented if the surface pressure load range L> S, but the leakage prevention can be secured with a margin when L = S, and it is not necessary to make it longer. Therefore, in the present invention, the surface pressure load range L is 1.5D.
The length condition is ≦ L ≦ S.

In the present invention, the surface pressure load range L is 1.5D≤L
Based on the premise that ≦ S is possible, it is preferable to shorten the upper plate 5 in the longitudinal direction to the necessary minimum based on the nozzle hole diameter melting loss and the surface roughness length of the upper plate 5,
As a result, the amount of refractory used in the upper plate 5 can be reduced. Further, in the present invention, the lower plate 6 on the sliding side is
Is centered on the nozzle hole 5A of the upper plate 5 on the fixed side
Since only the range of 1.5D ≦ L ≦ S is supported, when the surface pressure range is shortened, the cantilevered state becomes remarkable when fully closed, as shown in FIG. 3 (A). Therefore, the lower plate 6
It is preferable to provide a support guide in the range in which is slid to support so as not to be in a cantilever state.

The surface pressure load body for applying surface pressure to the mating surface of the upper plate 5 and the lower plate 6 from above and below uses an elastic body including springs such as coil springs and leaf springs and heat resistant rubbers. It is possible. In addition, a nut that holds an elastic body such as a spring is used to apply surface pressure by tightening a torque notch, a lever link mechanism is used to apply surface pressure through an elastic body such as a spring, and an elastic body such as a spring is applied from below to a pressing machine. Various mechanisms such as applying a surface pressure via the like can be used, and specifically, the mechanism described according to FIG. 7 is also applicable.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the drawings. A sliding nozzle device having a surface pressure load according to the present invention will be described in the case of a two-layer type, and FIG. 1 (vertical sectional view in the sliding nozzle width direction) and FIG. 2 (A-A arrow in FIG. 1 are shown. As shown in the plan view), an upper nozzle 4 is provided on a laid refractory material 3 constructed on the upper surface of an iron shell 2 constituting a molten metal container 1. An upper plate 5 on the fixed side is provided so as to be connected to the lower surface of the upper nozzle 4, and a lower plate 6 on the sliding side is arranged so as to be slidable in the horizontal direction in contact with the lower surface of the upper plate 5. .

In the present invention, as shown in FIGS. 3 (A) and 3 (B), the nozzle diameters of the nozzle holes 5A and 6A provided in the upper plate 5 and the lower plate 6 are set to D, and the lower plate 6 is fully closed to fully open. When the sliding stroke up to is S and the surface pressure load range in the plate longitudinal direction (sliding direction) centered on the nozzle hole 6A of the lower plate 6 on the fixed side is L, 1.5D ≦
Under the length condition of L ≦ S, a surface pressure load body that applies surface pressure from above and below is arranged on the mating surface of the upper plate 5 and the lower plate 6.

The surface pressure load body used in this embodiment has the following structure. The upper plate 5 is fixed to the upper fixed frame 8, and a plurality of coil springs 13 are arranged between the upper fixed frame 8 and the iron shell 2 as shown in the drawing. Lower plate 6
Are supported via a support guide 9 extending horizontally in the sliding range, and further supported by a lower fixed frame 10 having a size corresponding to the upper fixed frame 8. Also, the lower fixed frame 10 is attached to the lower metal frame 11 using the bolts 12,
Two hook receiving shafts 14 are provided at both ends of the lower metal frame 11 in the width direction. Bearings 15 are attached to the iron skin 2 at positions corresponding to the hook receiving shafts 14 arranged on the lower metal frame 11, and the bearings 15 are attached to the bearings 15 via pins 16.
17 is rotatably supported. And mounting bracket 17
The claw 18 provided at the tip of the is attached to and detached from the hook receiving shaft 14 arranged in the lower metal frame 11.

Here, an opening 19 is provided at the center of the upper fixed frame 8.
Is provided and is separated from the outer peripheral surface of the upper nozzle 4. Further, the lower fixed frame 10 and the lower metal frame 11 are provided with an opening 20 of substantially the same size in the center. Upper fixed frame 8
The lower fixed frame 10 has a length corresponding to the surface pressure range L determined by the above conditions in the plate longitudinal direction with the nozzle hole 5A provided in the fixed upper plate 5 as the center. The plate length L ₁ of the upper plate 5 is determined by the nozzle hole 5
The length is shortened to the minimum necessary based on the melting loss of A and the length of the plate surface roughness.

Next, an example of a procedure for assembling the upper plate 5 and the lower plate 6 will be described, but the procedure is not limited to this, and various procedures can be taken in consideration of workability. The upper plate 5 fixed to the upper fixed frame 8 is connected and attached to the lower surface of the upper nozzle 4, and at this time,
A plurality of coil springs 13 are set at predetermined positions between the upper fixed frame 8 and the iron skin 2. Since the lower fixing frame 10 attached to the lower metal frame 11 with the bolts 12 supports the lower plate 6 via the support guides 9, the lower plate 6 and the lower plate 6 are pushed while compressing the coil spring 13 from below the upper plate 5. Hit A pawl provided with a rotatable mounting bracket 17 at its tip through a pin 16 of a bearing 15 mounted on the iron shell 2.
By hooking 18 on the receiving shaft 14, the lower metal frame
Have 11 support. As a result, a series of mounting operations are completed, and a constant surface pressure is applied to the mating surfaces of the upper plate 5 and the lower plate 6 by the coil spring 13.

According to the present invention, the surface pressure load range L in the plate longitudinal direction centering on the nozzle hole 5A of the upper plate 5 and the lower plate 6 is 1.5D (nozzle hole diameter) ≤L≤S. As (stroke of the lower plate 6), the surface pressure is applied to the mating surface between the upper plate 5 and the lower plate 6, so that the sealing property is secured and the molten metal 7
Can be prevented from leaking. Further, the length L ₁ of the upper plate 5 is determined so as to ensure a minimum required length based on the hole diameter melting damage and the surface roughness of the nozzle hole 5A. It can be slid well, and the flow rate of molten metal can be controlled normally.

Further, since the lower plate 6 is supported by the support guides 9 arranged in the sliding length range,
It becomes possible to slide stably without being in a cantilever state. The results obtained when the sliding nozzle device having a surface pressure load according to the present invention is used for a ladle of a steelmaking factory in which surface pressure is applied over the entire length of the upper plate, is achieved over the entire length of the conventional upper and lower plates. Table 1 shows a comparison of conditions and application results when pressure is applied.

[0025]

[Table 1]

As shown in Table 1, according to the present invention, although the plate life is at the same level as in the prior art, the total length L _{1 of the} upper plate can be greatly shortened. A reduction in refractory cost could be achieved. In the above embodiment, the two-layer type sliding nozzle device has been described, but the present invention can be applied to a three-layer type sliding nozzle device other than the two-layer type.

[0027]

As described above, according to the present invention,
Since the surface pressure load range applied to the mating surfaces of the upper and lower plates can be reduced, the length of the upper plate can be shortened, and the refractory cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view in a width direction of a sliding nozzle showing an apparatus according to the present invention.

FIG. 2 is a plan view as viewed in the direction of arrows AA in FIG. 1;

FIG. 3 is an explanatory diagram of an apparatus according to the present invention.

FIG. 4 is a vertical sectional view showing a conventional device.

FIG. 5 is an explanatory view showing a state of pressurization on a conventional plate mating surface.

FIG. 6 is an explanatory diagram showing a pressurization state of a plate mating surface of a comparative example.

FIG. 7 is a vertical cross-sectional view showing a surface pressure applying device for a conventional mating surface of a plate.

[Explanation of symbols]

 1 Molten Metal Container 2 Iron Peel 3 Refractory Material 4 Upper Nozzle 5 Upper Plate 6 Lower Plate 7 Molten Metal 8 Upper Fixed Frame 9 Support Guide 10 Lower Fixed Frame 11 Lower Metal Frame 12 Bolt 13 Coil Spring 14 Hook Bearing Shaft 15 Bearing 16 Pin 17 Mounting bracket 18 Claw 19 Opening 20 Opening

Claims (3)

[Claims] 1. A sliding nozzle device which is mounted on the bottom of a molten metal container and controls the outflow amount of molten metal by sliding a lower plate on a sliding side with respect to an upper plate on a fixed side. When the diameter of the nozzle hole provided in the plate is D, the sliding stroke of the lower plate is S, and the surface pressure load range in the plate length direction centered on the nozzle hole of the upper plate is L, 1.5D ≦ L A sliding nozzle device having a surface pressure load body, wherein a surface pressure load body that applies a surface pressure from above and below is provided on a mating surface of an upper plate and a lower plate under a condition of ≤S. 2. The sliding nozzle device having a surface pressure load body according to claim 1, wherein the upper plate is shortened in the longitudinal direction to a necessary minimum length based on the melt damage of the nozzle hole diameter and the surface roughness length. . 3. A sliding nozzle device having a surface pressure load body according to claim 1, wherein a support guide for guiding the lower plate is provided in a range in which the lower plate slides.