JPH0645817B2 - Dispersion addition device for molten metal container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an apparatus for uniformly dispersing an additive such as a component adjusting agent into a molten metal or slag contained in a molten iron ladle, a molten steel ladle, etc. from above. Is.

[Conventional technology]

For example, slag with a high degree of oxidation that flows into the ladle during tapping of the converter in the steelmaking process becomes an oxidation source for molten steel. Therefore, in the production of high-cleanliness steel such as steel plates for automobiles and steel plates for can manufacturing, a reducing agent such as Al is put on the upper surface of the slag in the ladle after tapping to reduce and reform the slag. Attempts are being made. In applying such a slag reforming method, how to uniformly disperse the reducing agent throughout the slag in the ladle becomes a major issue.

Further, in order to prevent the temperature drop of molten iron and molten steel discharged into the ladle as much as possible, it is widely practiced to add various powder and granular heat insulating agents to the molten metal in the pot or the upper surface of the slag.

Even in the case of adding such a heat retaining agent, in order to obtain a sufficient heat retaining effect with a small basic unit, it is necessary to provide a charging device capable of uniformly spraying.

The following device has been devised as a device for uniformly dispersing and charging such additives into a ladle over a wide range. That is, as described in Japanese Utility Model Publication No. 59-165450, a collision disk is provided below the charging chute outlet, and a device for rotating the collision disk itself and diffusing it around, is disclosed in Japanese Utility Model Publication No. 54-33923. As described, there is a device that uses a turntable and a Hanon cone, and rotates the turntable to draw the trajectory of the lower Hanon cone and guide the powder / granular material to the container diameter method to drop it.

However, the above-mentioned conventional technique has the following problems.

[Problems to be Solved by the Invention]

It is difficult for the device shown in Japanese Utility Model Publication No. 59-165450 to disperse the input material around and around the axis of the collision plate provided below the input chute. On the contrary, when it is attempted to add the additive near the shaft core, it is difficult to spray the additive onto the outer peripheral portion. Therefore, it is difficult to disperse the additive uniformly over the entire surface of the ladle.

The apparatus disclosed in JP-B-54-33923 is superior to JP-B-59-165450 in the point of uniform dispersion.

However, since the additive flows from the outer peripheral edge of the Hanon cone toward the center, uneven distribution such as a large distribution at the center is unavoidable, and it is necessary to evenly distribute the additive over the entire ladle surface in the ladle. Not enough. Furthermore, there are problems that a large-scale driving device is required to rotate the turntable, the equipment cost is high, and that replacement of the bare metal on the Hanon cone is large.

[Means for Solving the Problems]

The present invention solves various problems in the above-described conventional powder / granular additive charging device, and adds additives such as a slag modifier and a heat retaining agent to molten iron in a ladle, molten steel, or the surface thereof. It is an object of the present invention to provide a device that can be dispersed with high accuracy and evenness over the entire upper surface of a certain slag or the like at a low equipment cost. That is, the gist of the present invention is, above the center of the molten metal container, communicate with the additive storage hopper, and
A rotatable charging chute is installed, and between the charging chute and the container, there is fixedly installed a bulky disperser having the apex located on the downward extension of the rotation axis of the charging chute and having a large number of dispersion holes on the entire circumferential surface. This is an apparatus for adding / dispersing an additive to a molten metal container.

In the present invention, the dispersion hole of the bulky disperser, if the bulky disperser is formed of a single iron plate or the like, is perforated, and the bulky disperser has multiple frameworks. If formed, it may be provided by any other suitable forming method such as forming using the gap between the frames. Further, the area of the dispersion hole can be gradually increased or decreased from the center of the bulky disperser toward the outer peripheral edge to arbitrarily adjust the distribution of the radial injection. The arrangement may be staggered in the circumferential direction to improve the dispersibility in the radial direction, or may be staggered in the radial direction to improve the dispersibility in the circumferential direction.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2 together with its operation.

The points that improve the uniformity of additive dispersion are the circumferential direction,
The reality is that the additive is evenly distributed evenly in the radial direction. FIG. 1 shows the apparatus of the embodiment.
That is, in the figure, 1 is a charging chute,
It is located on the central axis and is rotationally driven at a constant speed through the electric motor 4 and the speed reducer 5 arranged on the floor 11, thereby making it possible to uniformly supply the additive in the circumferential direction. A constant-speed cutting device 8 such as a rotary valve is provided on the pre-charging chute to measure the bulk specific gravity of the additive,
A constant speed cutting is performed according to the particle size, and a hopper 9 for receiving an additive is installed at the upper end. Further, below the outlet of the charging chute 1, there is installed a bulky disperser (hereinafter, simply referred to as a bulk) 2 in which a large number of holes are formed at a position where the apex is aligned with the rotation axis of the charging chute 1, and the radial direction The composition has a function of evenly and evenly dispersing the additive.

The hole diameter and the number of holes of the umbrella 2 can be freely selected according to the specific gravity and particle size of the additive, but when uniformity is strictly required in the radial direction, as shown in FIG. It is effective to gradually increase the hole diameter from the center.
On the other hand, when it is necessary to spread the additive thickly in the vicinity of the axial center portion in the radial direction and gradually thinning from the center, the difference between the hole diameter of the central portion of the umbrella 2 and the hole diameter of the outer peripheral portion is set to be small. You can also

Further, in order to be uniformly distributed in the circumferential direction, it is necessary for the charging chute 1 to rotate at least one or more times between the start and the end of charging the additive. You can improve the property.

The above is the basic configuration of the present embodiment, but it is easy to add the following auxiliary equipment depending on the usage environment. That is, FIG. 1 shows an apparatus for introducing Al for slag reforming in the adjusting and refining stage. This device is used in high temperature and dusty environment. For this reason, the chute 1 and the umbrella 2 have a dust collecting hood 6 having the same diameter as the ladle 10.
The dust collecting hood upper end opening is connected to the dust collecting duct 7. In addition, a refractory construction is performed on the back surface of the umbrella 2. Since the Casa 2 is constantly exposed to high temperature, deterioration cannot be avoided, but the Casa 2 is a very inexpensive cone-shaped iron plate with a hole, so even if it is replaced, the economical burden is small. In the device shown in FIG.
A pin 2 is used to remove the slag so that the slag can be easily replaced.
Is fixed.

Example of Actual Operation-1 Next, an example of actual operation of the apparatus of the embodiment shown in FIG. 1 will be described.

As a method of spraying Al for slag reforming in the steelmaking refining stage, massive Al having a particle size of 40 mm was charged on the upper surface of the slag in the ladle immediately after tapping of the converter, and the slag after completion of charging was sampled in multiple points in the plane direction, T. is an index of the degree of oxidation in slag. The variation of Fe concentration was investigated. Also, as a comparison,
A similar test was conducted using the device described in Japanese Patent No. The variation in Fe concentration was evaluated.

In this charging device, the cage 2 shown in FIG. 2 is used, and the diameter of the dispersion hole of the cage 2 in the figure is a = φ100 mm, b = c = φ130 m.
The diameter is increased toward the outer edge with m, d = e = φ150 mm. The outer diameter of the umbrella 2 was set to 1600 mm with respect to the ladle having the inner diameter of 4700 mm.

In the device disclosed in Japanese Utility Model Publication No. 54-33923, T.O. The variation in Fe concentration was σ = 1.3%.
On the other hand, in this operation example, the T.O. It was confirmed that the variation of Fe σ = 0.7% was obtained, the Al for reducing and modifying the slag was uniformly dispersed on the surface of the slag, and the slag could be uniformly modified as compared with the comparative example.

Actual Operation Example-2 In order to reduce the amount of molten steel temperature drop after the secondary refining until the casting, the heat insulating agent was sprayed on the molten steel surface in the pot using the apparatus shown in FIG. The molten steel temperature drop in this case is 0.4
° C / min.

As a comparative example, the same experiment was conducted with the apparatus disclosed in Japanese Utility Model Publication No. 54-33923, and as a result, the molten steel temperature drop was 0.54 ° C./min. This result shows that the heat insulating agent can be sprayed uniformly over the entire surface of the molten steel and slag in the ladle with the present device, as compared with the comparative example, and as a result, the heat insulating effect is enhanced.

〔The invention's effect〕

As described above, by using the device of the present invention,
Additives such as slag modifier and heat retaining agent can be evenly sprayed on the surface of ladle ladle steel. As a result, the unevenness of the slag reducing / modifying agent, heat insulating agent, etc., which has been a problem with conventional equipment, can be eliminated, and slag reforming and temperature drop prevention can be efficiently achieved, reducing the amount of these additives used. , And improved molten steel quality.

Further, since the present invention has an extremely simple structure as compared with the conventional device, it is possible to greatly reduce the facility cost and also reduce the maintenance cost, so that the economical effect is large.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of the apparatus of the present invention, and FIG.
It is a detailed view of the part of the umbrella in the figure, (a) is a side view, (b) is a plan view. 1 ... Input chute, 2 ... Casa 3 ... Connection pin, 4 ... Electric motor 5 ... Reducer, 6 ... Dust collecting hood 7 ... Dust collecting duct, 8 ... Constant speed cutting device 9 ... Reformer receiving hopper 10 …… Ladle, 11 …… Floor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Koichi Endo 1 Nishinosu, Oita-shi, Oita Pref. Nippon Steel Co., Ltd. Oita Works (72) Inventor Kiyoshi Ochi 1 Nishinosu, Oita-shi, Oita Pref. Oita Steel Works, Steel Works Co., Ltd.

Claims (1)

[Claims] 1. A charging chute that is rotatable and is connected to an additive accommodating hopper is installed above the center of the molten metal container, and a vertex is provided between the charging chute and the container below the rotation axis of the charging chute. A dispenser for adding an additive to a molten metal container, characterized in that a bulky disperser provided on the extension and provided with a large number of dispersion holes on the entire peripheral surface is fixedly installed.