JP2001129646A - Slide valve apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide valve apparatus which allows high quality casting eliminating the occurrence of drift in an immersion nozzle bore, the fluctuation in a discharge flow and inclusion of impurity such as slag, mold powder, etc., into a cast piece even when a molten steel flow is throttled. SOLUTION: The slide valve apparatus is provided with fixed plates and a sliding plate consisting of firebrick so as to control a flow rate at a tap hole of a molten metal vessel. The upper ends of pouring holes 5A, 5C of fixed plates 1, 3 and/or the upper end of the pouring hole 5B of sliding plate 2 are provided with inclined notches 6, 7, 8. Each notch communicates with the each pouring hole and is inclined downward and inside of the respective pouring hole. Each inclined notch orientation is constituted to deviate from the center axis S1, S2 or S3 respectively. This constitution makes it possible to generate a spiral flow when tapping the molten metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slide valve device, and more particularly, to a slide valve device having a fixed plate and a slide plate formed of refractory bricks for controlling a flow rate of a molten metal outlet. In particular, the present invention relates to a slide valve device used for a tundish for continuous casting and the like.

[0002]

2. Description of the Related Art Conventionally, as a flow control means for a tap hole of a molten metal container, for example, there is a pouring device provided with a three-layer or two-layer slide valve device for flow control. This pouring equipment is used as a means for continuous casting, usually
An immersion nozzle is provided continuously to the slide valve device. In this continuous casting, the molten steel supplied to the mold is supplied from a tundish through a casting nozzle while the amount of the molten steel is controlled by a slide valve device.

When controlling the flow rate of molten steel from the ordinary two-layer or three-layer slide valve device used here through a casting nozzle, the flow velocity distribution in the immersion nozzle hole is reduced. Due to the non-uniformity, a drift occurs and the discharge flow fluctuates. As a result, the molten steel flow in the mold also has an eccentric current, and impurities such as slag and mold powder are entrained in the slab, which may cause a deterioration in the quality of the cast product.

In order to solve such a problem, conventionally, as measures against these problems, for example, Japanese Patent Application Laid-Open No. 11-123509, Japanese Patent Application Laid-Open No. 11-47896, Japanese Patent Application Laid-Open No. 10-58098, and A technology such as that disclosed in Japanese Patent Publication No. 20958 has been proposed.

In the above-mentioned Japanese Patent Application Laid-Open No. 11-123509, a continuous casting nozzle having one or a plurality of step structures in the nozzle inner hole is provided. A continuous casting immersion nozzle with a specific radius or minimum cross-sectional area is described.

[0006] In Japanese Patent Application Laid-Open No. 11-47896, a continuous casting immersion nozzle provided with spiral projections on the inner wall is used to continuously stir molten steel in the nozzle and prevent drift in a mold. Nozzles are described.

In the above-mentioned Japanese Patent Application Laid-Open No. 10-58098, a magnet for generating a static magnetic field or a low-frequency AC magnetic field penetrating the immersion nozzle in the direction of the long side of the mold is arranged on the outer peripheral portion located on the molten metal surface of the immersion nozzle. Further, there is described a pouring device for continuous casting in which the drift in the nozzle caused by the opening and closing of the slide valve device and the deposit on the inner wall of the nozzle itself is reduced.

In Japanese Utility Model Application Laid-Open No. 59-20958, one or both of the fixed nozzle and the molten metal nozzle hole of the sliding plate are provided with a sliding angle for narrowing the molten metal nozzle hole of the sliding plate. A sliding nozzle having a negative pressure preventing inclined hole provided in the horizontal direction of the moving plate is described.

[0009]

In the technology described in the above-mentioned public information, the following problems remain. That is, in the technique described in JP-A-11-123509, although the stirring effect of molten steel is sufficient,
It is relatively difficult to form a plurality of step structures in the group of nozzle bores, which tends to increase the manufacturing cost.

In the technique described in Japanese Patent Application Laid-Open No. H11-47896, it is difficult to form spiral projections on the inner wall of the nozzle (particularly, double spiral projections), and the manufacturing cost increases.

In the technique described in Japanese Patent Application Laid-Open No. H10-58098, since a magnet for generating a static magnetic field or a low-frequency AC magnetic field is arranged, the equipment cost increases,
In addition, there is a problem that space is limited due to large facilities.

The technique described in Japanese Utility Model Laid-Open No. 59-20958 can reduce the local negative pressure in the nozzle hole, but cannot impart a swirl flow to the molten steel, and thus cannot sufficiently prevent drifting. No effect has been obtained.

As described above, the discharge flow from the immersion nozzle is
In order to achieve a flow with uniform velocity distribution without drift
In particular, improvements have been made in the shape of the immersion nozzle,
If the swirl flow can be given at the slide valve device portion which is the starting point of the drift of the molten steel flow, the drift prevention effect should be obtained most effectively. However, the conventional solution technology is
At present, the shape of the slide valve device, which is the starting point of the drift of the molten steel flow, has not been significantly improved.

On the other hand, in a model experiment using water, it is possible to install a swirl vane. However, installing a swirl vane that can withstand a high-temperature molten steel flow of 1500 ° C. or more requires a large cost and is commercially available. This is an extremely difficult technology.
In order to prevent the generation of local negative pressure in the nozzle hole, a sliding nozzle with an inclined hole that inclines the molten steel flow (Japanese Utility Model Application Laid-Open No. 59-20958) has been proposed and partially commercialized. However, a swirling flow cannot be provided, and a sufficient drift prevention effect has not been obtained.

Also, the method of generating an electromagnetic force corresponding to the flow velocity of the molten steel flow to reduce the drift in the nozzle and uniformly control the discharge flow has the problem of equipment space in a commercial-scale slab continuous casting machine. There is no practical application of a magnetic field to the immersion nozzle itself. Control of the flow of the molten metal in the mold by generating an electromagnetic force in the flow of the molten metal in the mold has already been performed, but at present, this method is also very costly.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to control the flow rate of molten steel even when the flow of the molten steel is restricted.
The flow velocity distribution in the immersion nozzle hole is uniform, there is no drift, and there is no fluctuation in the discharge flow.Therefore, there is no drift in the molten steel flow in the mold, and impurities such as slag and mold powder are trapped in the slab. It is an object of the present invention to provide a slide valve device which enables high-quality casting without occurrence of cracks.

[0017]

SUMMARY OF THE INVENTION A slide valve device according to the present invention is a slide valve device having a fixed plate and a slide plate formed of refractory brick for controlling a flow rate of a molten metal outlet. The upper edge of the hot water hole of the fixed plate and / or the upper edge of the hot water hole of the sliding plate communicate with the hot water hole and are inclined downward and inward of the hot water hole. An inclined notch portion is provided, and the notch portion is configured to be oriented in a direction shifted from a center axis of the hot water hole (Claim 1). Can be achieved.

Further, in the slide valve device according to the present invention, the inclined notch portion has a distance between a notch direction center line defining a direction of the inclined notch portion and a center axis of the hot water hole. (2) The inclined notch portion has a width in a direction orthogonal to the notch direction center line in the direction of the hot water. Not less than 1/4 and not more than 2/3 of the diameter of the hole, and the length in the center line direction is the diameter of the hot water hole.
0.7 to 1.5 times, and the inclination along the center line direction is inclined at an angle of 20 degrees to 60 degrees with respect to the plate sliding surface (claim Item 3) ・ The inclined notch formed in the fixed plate and the sliding plate is configured to be inclined substantially inward toward the inside of the hot water hole.
4).

Further, a continuous casting pouring apparatus according to the present invention is a continuous casting apparatus having one or a plurality of step structures inside the nozzle, which is continuous with the slide valve device according to any of the above and the slide valve device. It is characterized by the combined use of a submerged nozzle. (Claim 5)

(Operation) According to the slide valve device of the present invention, the upper edge of the hot water hole of the fixed plate and / or the upper edge of the hot water hole of the slide plate communicate with the hot water hole. And an inclined notch portion inclined downward and inward of the hot water hole is provided, and the notch portion is oriented in a direction deviated from the center axis of the hot water hole. Even when the flow rate of the molten steel is controlled, the swirling flow can be effectively generated in the molten steel even when the flow is restricted. (Claim 1)

Also, in the slide valve device according to the present invention, the distance between the center line of the inclined hole and the center axis of the hole is defined as 1 / the diameter of the hole. In the case where it is configured in the range of not less than 8 and not more than 3/8, an effective swirling flow can be obtained when the molten metal flows out. (Claim 2)

In the slide valve device according to the present invention, the inclined notch portion has a width in a direction perpendicular to the notch direction center line of not less than 4 and not more than ／ of the diameter of the hot water hole.
And the length in the center line direction is 0.7 times or more the diameter of the hot water hole.
1.5 times or less, furthermore, the inclination along the notch direction center line direction is configured to be inclined at an angle of 20 degrees or more to 60 degrees or less with respect to the plate sliding surface, A swirling flow can be obtained effectively. (Claim 3)

Further, in the slide valve device according to the present invention, the inclined cutouts formed in the fixed plate and the slide plate are configured so as to be inclined substantially inward toward the inside of the hot water hole. Thus, when the molten metal flows out, a turning force can be alternately applied to the molten metal. (Claim 4)

According to the pouring apparatus for continuous casting according to the present invention,
By using a slide valve device according to the present invention and a continuous casting immersion nozzle having a single-stage or a plurality of step structures inside the nozzle in combination with the slide valve device, the flow is reduced when controlling the flow rate of molten steel. In this case, the flow velocity distribution in the immersion nozzle hole is uniform, there is no drift, and there is no fluctuation in the discharge flow.There is no drift in the molten steel flow in the mold, and slag, Incorporation of impurities such as mold powder can be prevented.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a slide valve device according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a main part of a three-layer slide valve device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the plane AA in FIG. 1, and FIG.
FIG. 4 is a cross-sectional view taken along a plane CC of FIG. 1. FIG. 5 is a detailed view of the vicinity of the hot water hole, and FIG. 6 is a cross-sectional view of a portion along the FF plane in FIG. FIG. 7 is a cross-sectional view of a two-layer slide valve device according to a second embodiment of the present invention. FIG. 8 is a cross-sectional view along the DD plane in FIG. 7, and FIG. 9 is a cross-sectional view along the EE plane in FIG.

(First Embodiment) As shown in FIG. 1, a slide valve device 10 according to a first embodiment is sandwiched between an upper plate 1 and a lower plate 3, which are fixed plates, in the direction of arrow G. Sliding plate 2-3
It consists of two plates. The upper edges of the hot water holes 5A, 5C of the upper plate 1 and the lower plate 3 and the upper edge of the hot water hole 5B of the sliding plate 2 communicate with the hot water holes 5A, 5B, 5C. The inclined cutouts 6, 7, 8 are provided at positions slightly displaced from the center line H in the sliding direction (the direction in which the sliding plate 2 slides and the direction G in the drawing).

In this embodiment, the inclined notches 6 and 8 formed on the fixed plate (upper plate 1 and lower plate 3) and the inclined notch 7 formed on the sliding plate 2 are: The hot water holes 5A, 5B, and 5C are configured to be inclined substantially inward toward the inside (alternately in opposite directions in the direction in which the molten metal flows).

The above-mentioned inclined notches 6, 7, and 8 are provided with inclined surfaces that are appropriately inclined downward and inward with respect to the hot water holes 5A, 5B, and 5C, respectively. "Central direction center line MC (same line as FF line)" shown in 5
) Are directed to directions deviated from the central axes S1, S2, S3 of the hot water holes 5A, 5B, 5C as described later.

As shown in FIGS. 5 and 6 in an enlarged manner, the inclined notches 6 and 8 (the inclined notches 6 and 8 are the same except that the left and right directions of the inclined notch 7 are opposite to each other).
8, the enlarged view is omitted. ) Is a structure that is inclined at an inclination angle α with respect to the plate sliding surface 9 in the present embodiment, and is notched in a shape of a part of a curved surface as appropriate. The hot water holes 5A and 5C are configured so as to be directed in directions away (shifted) from the central axes S1 and S3 by a distance X as appropriate.

In this specification, the notch direction center line MC is a center line that defines the direction of the inclined notch portions 6 and 8, and in the present embodiment, the notch width C is bisected vertically. And a line along the direction in which the molten metal flows through the cutouts 6 and 8 when the molten metal flows.

In FIGS. 5 and 6, A represents the diameter of the hot water holes 6 and 8 provided in the plates 1 and 3, B represents the length of the inclined cutouts 6 and 8, and C represents the inclined cut. Notch 6,8
, D is the depth to the bottom of the inclined cutouts 6, 8, α is the angle of the inclined cutout with respect to the plate sliding surface 9, and X is the center S1, S3 of the hot water holes 5A, 5C. Eccentric distance from eccentric to the center line of inclined notch 6, 8 (eccentric distance)
Is shown.

In the present embodiment, the eccentric distance X is preferably not less than 1/8 and not more than 3/8 of the diameter A of the hot water holes 5A, 5C.
As a result of the study of the present inventors, it is difficult to provide a sufficient swirling flow to the outflowing molten metal if the diameter is less than 1/8 of the diameter A of the hot water holes 5A and 5C. 5A, 5C
If the diameter A exceeds 3/8 of the diameter A, the force for imparting the swirling flow becomes small, and a sufficient swirling flow cannot be obtained.

The width C of the eccentric inclined cutouts 6, 8 is preferably not less than 4 and not more than ／ of the hot water holes 5A, 5C. If the width C of the eccentric inclined cutouts 6, 8 is less than 1/4 of the hot water holes 5A, 5C, the swirl flow cannot be created entirely in the nozzle, which is insufficient. If the width C of the inclined cutouts 6, 8 exceeds 2/3 of the hot water holes 5A, 5C, the effect of imparting swirling flow is insufficient.

The length B of the inclined notches 6 and 8 is
The opening degree (opening area of hot water hole / cross-sectional area of hot water hole) of the nozzle hole of the slide plate during general hot water flow control is 30% to 70%, and the length of the inclined cutouts 6, 8 is B is desirably in a range of 0.7 times or more and 1.5 times or less of the hot water hole diameter.

Plate sliding surface 9 of inclined notches 6 and 8
Is preferably inclined at an angle of not less than 20 degrees and not more than 60 degrees. This is the inclined notch 6,
When the angle of 8 is less than 20 degrees, the metal is easily inserted into the plate sliding surface 9, and the possibility of causing the plate to open is increased. On the other hand, inclined notch portions 6, 8
When the angle with respect to the plate sliding surface 9 exceeds 60 degrees, there is no effect of providing a swirling flow, and a sufficient drift prevention effect cannot be obtained.

In the three-layer slide valve device according to the first embodiment shown in FIG. 1, the inclined notches 6, 7, 8 of the upper plate 1, the slide plate 2, and the lower plate 3 are formed as described above. , From the top in the opposite direction. If the inclined cutouts 6, 7, 8 are provided in directions alternately opposite to each other in the direction in which the molten metal flows, the flow can be urged at a position along the flow of the swirling flow. The effect of providing a swirling flow is great.

Second Embodiment As shown in FIGS. 7, 8, and 9, a slide valve device 20 according to a second embodiment of the present invention is a two-layer slide valve device. And the inclined notch 26 of the upper plate 21 and the hole of the inclined notch 27 of the sliding plate 22 are provided in the same direction (left side in FIG. 7). Note that FIG.
8 and 9, S4 and S5 are hot water holes 5D and 5E.
Is the central axis. 8 and 9 are cross-sectional views of a portion along a line DD and a line EE in FIG.

Also in the second embodiment, the inclined notch 26 of the upper plate 21 which is a fixed plate and the inclined notch 27 formed in the sliding plate 22
It is a structure which is inclined in the same direction toward the inside of the hot water holes 5D, 5E in substantially the same shape. In this way, even with the inclined notch formed in the same direction, a turning force can be applied to the molten metal.

(Third Embodiment) FIG. 10 shows a plate 31 as a main part of a slide valve device according to a third embodiment of the present invention. In the third embodiment,
Inclined notch 3 communicating with hot water hole 35 of plate 31
6 is configured so that its shape becomes a part of the outer surface of the cylinder.

(Fourth Embodiment) FIG. 11 shows a plate 41 as a main part of a slide valve device according to a fourth embodiment of the present invention. In the fourth embodiment,
Inclined notch 4 communicating with hot water hole 45 of plate 41
6 is configured so that its shape becomes a part of a square pole (the inclined surface is flat).

(Fifth Embodiment) FIG. 12 shows a plate 51 of a main part of a slide valve device according to a fifth embodiment of the present invention. In the fifth embodiment,
Inclined notch 5 communicating with hot water hole 55 of plate 51
6 is configured so that its shape becomes a part of a triangular prism (two inclined planes).

As described above, in the present invention, as described above, the shape of the inclined cutout may be formed by cutting out an appropriate curved surface, a cylinder, a quadratic prism, or a triangular prism. In addition to the above, any shape such as a notch in a part of a sphere may be used. However, a notch in a part of a cylinder is advantageous in that there is no local concentrated stress and cracks are suppressed.

(Sixth Embodiment) Further, the slide valve device according to the present invention can be used for a pouring device for continuous casting as shown in FIG. As shown in FIG. 13, the device according to the sixth embodiment is a slide valve device 1.
0 (shown in FIG. 1) and the nozzle 60 having a step structure between the small diameter d1 part and the large diameter D part in the inner diameter (one step or the like in Japanese Patent Application Laid-Open No. 11-123509). It is a continuous casting pouring device 70 having a structure using a combination of a continuous casting nozzle having a plurality of step structures. The pouring device 70 for continuous casting configured as described above can apply an effective swiveling force to the molten metal at the time of discharging the molten metal, and is further uniformed by the synergistic effect of the slide valve device 10 and the nozzle 60. A swirling flow of molten steel in a simple mold is obtained.

[0044]

As described above, in the slide valve device according to the present invention, the hot water is supplied to the upper edge of the hot water hole of the fixed plate and / or the upper edge of the hot water hole of the slide plate. An inclined cutout communicating with the hole and inclined downward and inward of the hot water hole is provided, and the direction of the notch is directed to a direction deviated from the center axis of the hot water hole. Therefore, even when the flow rate of the molten steel is controlled, the swirling flow can be effectively generated even when the flow is restricted, the flow velocity distribution in the immersion nozzle hole becomes uniform, and there is no occurrence of drift and the discharge flow The present invention provides a low-cost slide valve device that enables high-quality casting that does not cause fluctuations in the molten steel flow in the mold, and does not cause slag, mold powder, or other impurities in the slab. be able to. (Claim 1)

Further, in the slide valve device according to the present invention, the distance between the notch direction center line defining the direction of the inclined notch portion and the center axis of the hot water hole is 1/1 / the diameter of the hot water hole. With the configuration in the range of not less than 8 and not more than 3/8, it is possible to provide a slide valve device capable of obtaining a swirling flow more effectively when the molten metal flows out. (Claim 2)

In the slide valve device according to the present invention, the inclined notch portion has a width in a direction orthogonal to the notch direction center line made to be not less than の and not more than 径 of the diameter of the hot water hole. The length in the center line direction is configured to be 0.7 times or more and 1.5 times or less of the diameter of the hot water hole, and the inclination along the center line direction in the notch direction is equal to the plate sliding surface. By being configured to be inclined at an angle of not less than 20 degrees and not more than 60 degrees, it is possible to provide a slide valve device capable of effectively obtaining a swirling flow. (Claim 3)

Further, in the slide valve device according to the present invention, the inclined notch formed in the fixed plate and the slide plate is inclined substantially inward toward the inside of the hot water hole. Therefore, it is possible to provide a slide valve device capable of obtaining a more effective swirl flow when the molten metal flows out. (Claim 4)

The pouring device for continuous casting according to the present invention uses the slide valve device of the present invention and a continuous casting immersion nozzle having one or more steps inside the nozzle, continuously with the slide valve device. Therefore, even when the flow is restricted when controlling the flow rate of the molten steel, the flow velocity distribution in the immersion nozzle hole becomes uniform, there is no occurrence of drift, and the discharge flow does not fluctuate, and the molten steel in the mold It is possible to provide a pouring apparatus for continuous casting that enables high-quality casting without causing any drift in the flow and without entrapment of impurities such as slag and mold powder in the slab. (Claim 5)

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a three-layer slide valve device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a portion along the AA plane in FIG.

FIG. 3 is a cross-sectional view of a portion along a BB plane in FIG. 1;

FIG. 4 is a cross-sectional view of a portion taken along a plane CC in FIG.

FIG. 5 is an enlarged plan view of the vicinity of a hot water hole according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of a portion along the FF plane in FIG.

FIG. 7 is a sectional view of a main part of a two-layer slide valve device according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view of a portion along a DD plane in FIG. 7;

9 is a cross-sectional view of a portion along the EE plane in FIG.

FIG. 10 is a perspective view of a plate according to a third embodiment of the present invention.

FIG. 11 is a perspective view of a plate according to a fourth embodiment of the present invention.

FIG. 12 is a perspective view of a plate according to a fifth embodiment of the present invention.

FIG. 13 is a sectional view of a main part of a pouring device for continuous casting according to a sixth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper plate 2 Sliding plate 3 Lower plate 5A, 5B, 5C, 5D, 5E, 35,45,55 Hot-water holes 6,7,8,26,27,36,46,56 Inclined notch 9 Plate slide Moving surface 10, 20 Slide valve device 60 Nozzle 70 Pouring device for continuous casting

Claims (5)

[Claims] 1. A slide valve device comprising a fixed plate and a sliding plate formed of refractory brick for controlling a flow rate of a molten metal container tap hole, wherein an upper edge portion of a hot water hole of the fixed plate and / or Alternatively, an inclined notch is provided at an upper edge of the hot water hole of the slide plate and communicates with the hot water hole and is inclined downward and inward of the hot water hole. A slide valve device, the direction of which is deviated from the central axis of the hot water hole. 2. The inclined notch portion, wherein a distance between a notch direction center line defining its direction and a central axis of the hot water hole is 1/8 or more and 3/8 or less of a diameter of the hot water hole. 2. The slide valve device according to claim 1, wherein the slide valve device is configured as follows. 3. The inclined notch portion has a width in a direction orthogonal to a center line of the notch direction equal to a diameter of the hot water hole.
Not less than / 4 and not more than 2/3, and the length in the center line direction is not less than 0.7 times and not more than 1.5 times the diameter of the hot water hole, and further along the notch direction center line direction. 3. The slide valve device according to claim 1, wherein the inclination is inclined at an angle of not less than 20 degrees and not more than 60 degrees with respect to the plate sliding surface. 4. The method according to claim 1, wherein the inclined cutouts formed in the fixed plate and the sliding plate are configured to be inclined substantially inward toward the inside of the hot water hole. 4. The slide valve device according to claim 1, wherein 5. A continuous casting immersion nozzle having one or a plurality of step structures inside the nozzle, which is continuous with the slide valve device according to claim 1 and the slide valve device. Pouring equipment for continuous casting.