JP3489424B2 - Slag cutting stopper and converter with it - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slag cutting stopper for preventing slag inflow into an outflow as much as possible when tapping molten steel and hot metal from a converter, and a converter equipped with this stopper. Is.

[0002]

In the refining process such as a converter, it is impossible to eliminate the presence of slag, but in the subsequent refining of steel, the presence of slag deteriorates the cleanliness of the steel and the fire resistance of its container. Since the product life is shortened, it is necessary to separate the slag and the steel when the steel is tapped from the converter as much as possible.

Therefore, for the purpose of preventing slag outflow (hereinafter referred to as slag cut), for example, Japanese Patent Publication No. 2-9.
As shown in FIG. 8, Japanese Laid-Open Patent Publication No. 642 discloses a rod 51 that holds a slag cutting stopper 50 on the tip side, a boom 53 that is a cylinder 52 that projects or retracts the rod 51, and a base end of the boom 53. Cylinder 54 that tiltably supports the portion, a base end portion of boom 53 that is tiltably supported, and bracket 56 that reciprocates on guide 55 with cylinder 54 mounted, and the base end portion of guide 55 that is pivotally supported. Then, a slag cutting device including a pivot 58 for rotating the guide 55 by a motor 57 is disclosed.

In the slag cutting device disclosed in Japanese Patent Publication No. 2-9642, the slag cutting stopper 50 held at the tip of the boom 53 has a spear shape, and the converter is used before the slag flows out during tapping. In the tapped hole 59a of 59, the motor 57
Is driven to rotate the pivot 58 to move the bracket 56 so as to approach the converter 59, and the cylinder 54 is driven to tilt the boom 53 to attach the slag cutting stopper 50 to the tapped hole 59a. Make a slag cut. Then, the slag cutting stopper 50 is replaced after each tapping operation.

Further, Japanese Patent Publication No. 62-1448 discloses that
As shown in FIG. 9, the gate-shaped frame 6 provided on the floor surface
1. A trolley 63 running on the front of the converter in front of the furnace opening of the converter 62 in a direction intersecting with the converter axis, and provided on the trolley 63.
There is disclosed a slag cutting device including an arm drive mechanism 65 that allows an arm 66 holding a slag cutting stopper 64 at its tip to move forward and backward and tilt.

The slag cutting device disclosed in Japanese Examined Patent Publication No. 62-1448 discloses a converter 62 at the time of tapping and before the slag flows out.
The trolley 63 and the arm drive mechanism 65 are driven into the tapped hole 62a of FIG. The slag cutting stopper 64 is held by the arm 66 even after being attached to the tapping hole 62a, and is removed from the tapping hole 62a at the end of tapping.

Further, Japanese Patent Publication No. 62-2605 discloses that
As shown in FIG. 10, an arm 71 capable of advancing and retracting by attaching a slug cutting stopper 70 to the tip thereof, and a base end portion of the arm 71 being pivotally supported to rotate the base end portion, the arm is tilted. A tilt mechanism 72, a lifting mechanism 73 for raising and lowering the tilt mechanism 72, a slug that is provided near the tip of the arm 71, and includes a limit device 74 for detecting relative movement between the arm 71 and the slag cutting stopper 70. A cutting device is disclosed.

The slag cutting device disclosed in Japanese Examined Patent Publication No. 62-2605 discloses a steel tapping hole 75a of the converter 75 during tapping.
The slag cutting stopper 70 attached to the slag is pulled up to produce molten steel, and the limit device 74 detects the time when the steel production ends and the tilting mechanism 72 and the elevating mechanism 73 are driven to perform the slag cutting, and the slag cutting stopper is driven. 7
0 is attached to the tapped hole 75a.

Further, Japanese Patent Publication No. 3-68924 discloses that
As shown in FIG. 11, a cylinder 83 and an arm 81 in which the base end of the arm 81 is held by the tip of a rod 82 so that the arm 81 having a slag cutting stopper 80 attached to the tip thereof can be tilted, can be used. An arm drive mechanism 84 for moving forward and backward, a cylinder 83, and an arm drive mechanism 84
And a moving carriage 8 for moving the lifting mechanism 85 toward and away from the converter 86.
A slag cutting device composed of 7 or the like is disclosed.

The slag cutting device disclosed in Japanese Examined Patent Publication No. 3-68924 is designed to cut the slag when tapping steel.
The movable carriage 87 is moved so as to approach the converter 86, the elevating mechanism 85 is driven to descend, the cylinder 83 and the arm driving mechanism 84 are descended, and the arm 81 is tilted and advanced to bring out the slag cutting stopper 80. Steel hole 86a
Attach to. This slag cutting stopper 80 is 1
It is replaced after every tapping.

[0011]

However, Japanese Patent Publication No. 2-9642 and Japanese Patent Publication No. 3-6892 mentioned above.
In the slag cutting device disclosed in Japanese Patent Publication No. 4, since it is impossible to reuse the stopper for slag cutting, not only the replacement process of the stopper is added but the efficiency is deteriorated, but also the work of mounting the stopper during tapping is performed. Slag cut may fail due to the flow of hot water while tilting the furnace.
Further, there is a problem that it is very dangerous because it is a stopper loading operation during tapping.

Further, in the slag cutting device disclosed in Japanese Patent Publication No. 62-1448 and Japanese Patent Publication No. 62-2605, the stopper charging device becomes very large, and, for example, repair is performed at the back of the converter. However, there is a problem that work such as addition of ferroalloys is hindered, and in this case also, there is a problem that slag cutting may fail due to the flow of molten metal during tilting of the furnace.

The present invention has been made in order to solve the above-mentioned conventional problems, and it is possible to surely perform slag cutting and to reuse the slag without complicating the structure. An object of the present invention is to provide a stopper for cutting and a converter capable of improving the use efficiency.

[0014]

In order to achieve the above-mentioned object, the stopper for slag cutting of the present invention comprises a middle stopper portion which is attached in the middle of a core bar extending below the supporting portion, and a middle stopper portion. Under the stopper, there is a steel hole drop-out prevention part attached to the core metal at a distance that is sufficiently longer than the length of the steel tap hole, and the middle bar part and the steel hole drop-out prevention part are connected to the core bar. Was coated with refractory. According to this structure, even if the converter is tilted, the tool for preventing the tapped steel hole from coming off does not fall off by engaging with the tapped steel hole of the converter, so that it can be reused.
Further, the converter of the present invention is one in which the stopper for slag cutting is attached to the tapped hole, and by doing so,
Use efficiency of the converter is improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The slag cutting stopper of the present invention is a slag cutting stopper which is inserted into a tapping hole in order to prevent slag from flowing out when tapping from a converter, A middle stopper part installed in the middle of a core bar extending below this support part and a steel hole dropout attached to the core bar below the middle stopper part with a distance sufficiently longer than the steel hole length. The present invention has a prevention part, and a middle stopper part, a steel hole drop-out prevention part, and a core bar connecting these parts are covered with a refractory material.

The slag-cutting stopper of the present invention is attached to the tapping hole before pouring the hot metal into the converter. In this installation, the steel hole drop-out prevention part is inserted into the steel hole from the inner surface of the converter toward the outer surface, and the steel hole drop-out prevention part projecting to the outer surface of the converter is attached to, for example, a core bar. The outer surface of the converter is engaged with the steel hole drop-out prevention portion by bending 90 ° (to the inserting direction). The slag cut that is carried out when the molten iron injected into the converter is smelted and tapped from the converter is carried out.When tapping, the middle stopper part lighter than the specific gravity of the molten steel and heavier than the specific gravity of the slag floats in the molten steel. As a result, when the tapped steel hole is opened, the molten steel flows out, and when the slag approaches the tapped steel hole after this, the intermediate stopper portion descends to close the tapped steel hole reliably.

Further, the converter of the present invention is one in which the above-mentioned stopper for slag cutting of the present invention is installed in the tapping hole, and the stopper for slag cutting of the present invention can be repeatedly used, so that Use efficiency is improved.

[0018]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows the structure of the slag cutting stopper of the present invention. FIG. 2 shows another structure of the slag cutting stopper of the present invention. FIG. 3 shows a steel output situation in a converter equipped with the slag cutting stopper of the present invention. 4 to 7 each show a comparison situation between the present invention and the conventional example.

A stopper 1 for slag cutting (hereinafter referred to as stopper 1) of the present invention is attached to a supporting portion 3 formed at a base end portion of a cored bar 2 and an intermediate portion of the cored bar 2 extending from the supporting part 3. It has a middle stopper portion 4 and a steel hole drop-out preventing portion 5 attached to the core metal 2 below the middle stopper portion 4 with a distance sufficiently longer than the steel hole length. The stopper portion 4 and the tapped hole drop-out prevention portion 5 and the core metal 2 connecting them are covered with a refractory material 6.

The supporting portion 3 is formed into a ring shape so that it can be engaged with the tip of a jig for attaching a stopper, for example. Since it is not crushed, it is not necessary to cover the refractory.

The middle stopper portion 4 has a cored bar 2 inside thereof.
Has a frusto-conical member 2a connected to each other. The frusto-conical member 2a has a bulging portion directed toward the supporting portion 3 and a small diameter portion directed toward the tapped hole dropout prevention portion 5. ing. The outer surface of the frustoconical member 2a is coated with, for example, a chrome ramming material as the refractory material 6 to form a semi-spindle shape. Further, the intermediate stopper portion 4 is set to have a specific gravity lighter than molten steel and heavier than slag.

The steel hole drop-out prevention portion 5 shown in FIG.
Guide grooves 5c are formed at both ends of a tubular member 5b that is inserted into a mounting pipe 5a that is welded at a right angle to the distal end of the guide member, and the base end portion of the core metal 5B in the stopper portion 5A is fitted into the guide groove 5c. The base end portion of the core metal 5B is pivotally supported in the tubular member 5b by a pin 5C orthogonal to the guide groove 5c, and the tip end side of the stopper portion 5A is configured to open in one direction with respect to the core metal 2. ing. In the tapped hole drop-out prevention portion 5 shown in FIG. 1, a mounting member 5d is further welded to the lower end of the mounting pipe 5a.

Further, the steel hole drop-out prevention portion 7 shown in FIG.
Guide grooves 7b are formed at both ends of a mounting pipe 7a that is welded orthogonally to the tip of the core metal 2, and the base end of the core metal 7B in the stopper portion 7A is fitted into the guide groove 7b. The end portion is pivotally supported by a pin 7C so that the tip end side of the stopper portion 7A is separated from the cored bar 2 and opens.

The core metal 2 connecting the above-mentioned middle stopper portion 4 and the tapped hole drop prevention portion 5 (7) and the tapped hole drop prevention portion 5 (7) are made of refractory material 1, for example, 1600.
Covers refractory castables for ℃.

Next, the usage of the stopper 1 having the above structure will be described. Before injecting the hot metal into the converter 10, FIG.
As shown in (a), the stopper 1 is attached to the tapped hole 10a. For this installation, use the stopper 5A (7A) for the core metal 2
It is fixed in advance with a string or the like so as not to be opened, and a jig (not shown) is engaged with the support portion 3 to attach it to the tapped hole 10a. After this, the jig is retracted and the stopper portion 5A (7A)
When the cord that has stopped is removed, the stopper portion 5A (7A) is opened, and the stopper 1 is engaged with the tapped hole 10a.

After the above, as shown in FIG. 3 (b), the converter 1
0 is tilted in the clockwise direction in the drawing to inject the hot metal from the furnace port 10b, and then the converter 10 is tilted in the counterclockwise direction in the drawing as shown in FIG. 3 (c) to refine the injected hot metal. Three
As shown in (d), the converter 10 is tilted so that the tapping hole 10a is located below. Here, in the converter 10, the molten steel layer 11 is formed in the lower part, and the slag layer 12 is formed in the upper part.

When the converter 10 is tilted so that the tapped hole 10a is located below, the middle stopper portion 4 of the stopper 1 has a specific gravity lighter than molten steel and higher than slag. It is located near between the molten steel layer 11 and the slag layer 12, and as shown in FIG. 3 (d), the middle stopper portion 4 floats in the molten steel in the converter 10 until the completion of the molten steel output, so that it exits. The steel hole 10a is opened.

When the molten steel decreases, that is, when the slag layer 12 descends to the surface of the converter 10 where the tap hole 10a is formed, as shown in FIG. 3 (e), the intermediate stopper portion 4 is tapped. The hole 10a is closed, slag cutting is performed, and tapping is completed.

After this, the converter 10 is shown in FIG.
Tilt is performed in the order of (f), FIG. 3 (g), and FIG. 3 (h). Rotate in the clockwise direction in the drawing so that the furnace opening 10b faces upward (see FIG.
(F)), and further rotated in the clockwise direction in the drawing so that the tapped hole 1
0a is turned upside down (Fig. 3 (g)), and
The waste is completed in the state of (h). At the time of the waste, since the tapped steel hole 10a is on the upper side, the middle stopper portion 4 is lowered from the tapped steel hole 10a by its own weight to close the tapped steel hole 10a.
Is opened. Even if the stopper 1 stops in this state, it does not hinder the next tapping.

After the step shown in FIG. 3 (h), the converter 10 is tilted to the state shown in FIG. 3 (b), and the subsequent steps are repeated. Since the stopper 1 is covered with a refractory material, at least 2
Can be used repeatedly for tapping.

By the way, the stopper 1 of the present invention and a conventional example (for example, Japanese Examined Patent Publication No. 2-9642, Japanese Examined Patent Publication No. 62-144).
No. 8, JP-B-62-2605, JP-B-3-68924
(When the slag cutting stopper described in Japanese Patent Publication etc. is slag cut using a slag cutting device)
The results of comparison in a 50t converter are shown below.

As shown in FIG. 4, the success rate of slag cutting was 90% in the conventional example, but 100% in the present invention. Further, comparing the thickness up to the upper surface of the slag layer 12 at the time of slag cutting, as shown in FIG.
In contrast to the above, the present invention can be suppressed to about 40 mm. The results shown in FIG. 4 and FIG. 5 show that in the conventional example, the slag outflow timing is externally observed and the slag cutting stopper is attached to the tapped hole. Attached, molten steel layer 11
Since the tapping hole 10a is closed by utilizing the difference in specific gravity between the slag layer 12 and the slag layer 12, the slag cut becomes reliable, and the thickness of the slag layer 12 up to the upper surface is
This is because only 2.

In addition, as for the life, a conventional example (for example, Japanese Patent Publication No.
The stopper described in Japanese Patent Publication No. 9642 and Japanese Examined Patent Publication No. 3-68924) can be used only once, whereas the present invention can be used 2.7 times (certainly twice), and the life is more than double. Extended. And the cost reduction effect could be suppressed to half compared with the conventional example. This is because the middle stopper portion 4 of the stopper 1 of the present invention, the steel hole drop-out prevention portion 5 (7) and the core metal 2 connecting them are covered with a refractory material.

On the other hand, in the converter of the present invention, the stopper 1 having the above effect is installed in the tap hole 10a of the converter 10. By using this converter 10, the stopper 1 is as described above. The same effect can be obtained, and further, the converter 10 itself has improved usage efficiency.

The stopper 1 of the present invention is not limited to the above embodiment, and the following modifications are possible. For example, even if the shape of the intermediate stopper portion 4 is not the one shown in the above embodiment, for example, Cover with refractory, frustoconical, triangular pyramid,
It may be formed in a hemispherical shape, and the tapped hole drop-out prevention portion 5 (7) may have stopper portions 5A and 7A opened in, for example, four directions and three directions. The article may be coated with other materials that can withstand high temperatures.

[0036]

As described above, the stopper for slag cutting according to the present invention is provided with a middle stopper portion mounted in the middle of a core bar extending below the supporting portion, and a steel tapped below the middle stopper portion. It has a tapped hole removal prevention part attached to the core metal at a distance that is sufficiently longer than the hole length, and the middle stopper part and the tapped hole removal prevention part and the core metal connecting them are covered with a refractory material. , The stopper for slag cutting can be reused, the step of replacing the stopper is not required and the efficiency is improved, and the middle stopper portion opens and closes the tapped hole by the difference in specific gravity between the molten steel and the slag so that the slag cutting can be performed. Be certain. Further, in the converter of the present invention, since the stopper for slag cutting is attached to the tapped hole, the efficiency of use of the converter is improved.

[Brief description of drawings]

1A and 1B show a structure of a stopper for slag cutting according to the present invention, FIG. 1A is a front view, and FIG.

2A and 2B show another structure of the stopper for slag cutting of the present invention, FIG. 2A is a front view, FIG. 2B is a partially cutaway view of a tapped hole drop-out prevention portion, and FIG. It is a side view which shows a hole fall prevention part.

3 (a) to 3 (h) are diagrams showing a procedure from mounting the slag cutting stopper of the present invention to the converter tapping hole to performing refining work and then performing waste.

FIG. 4 is a diagram showing a situation in which the slag cutting success rate is compared between the case of using the slag cutting stopper of the present invention and the conventional example.

FIG. 5 is a diagram showing a situation in which the thickness up to the upper surface of the slag layer is compared between the case of using the slag cutting stopper of the present invention and the conventional example.

FIG. 6 is a view showing a situation in which the service lives of the slag cutting stopper of the present invention and the conventional example are compared.

FIG. 7 is a diagram showing a situation in which the cost reduction effect is compared between the case of using the slag cutting stopper of the present invention and the conventional example.

FIG. 8 is a view showing a conventional slag cutting device.

FIG. 9 is a diagram showing a conventional slag cutting device.

FIG. 10 is a diagram showing a conventional slag cutting device.

FIG. 11 is a view showing a conventional slag cutting device.

[Explanation of symbols]

1 Stopper (for slag cut) 2 core metal 3 branches 4 Middle stopper part 5 Steel hole dropout prevention part 7 Steel hole dropout prevention part 10 converter

Front page continuation (56) Reference JP-A-47-34110 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C21C 5/46 103

Claims (2)

(57) [Claims] 1. A slag-cutting stopper to be inserted into a tapping hole in order to prevent slag from flowing out of a converter when tapping the steel. The stopper includes a support and a core bar extending below the support. It has a middle stopper part attached on the way and a steel hole drop-out prevention part attached to the core under the middle stopper part with a distance sufficiently longer than the steel hole length. Also, a stopper for slag cutting, characterized in that a refractory material is coated on the tapped hole drop-out prevention portion and a core metal connecting them. 2. A converter, wherein the slag cutting stopper according to claim 1 is attached to a tapped hole.