JPS632221Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention prevents smelting slag from flowing out when transferring molten metal from a smelting furnace to a container, from a container to another container, or from a container to a smelting furnace. This relates to a device for preventing smelting slag from flowing out.

(Prior art and its problems) When a predetermined amount of molten metal is received in a molten metal pot, etc., and then poured into another container, as much as possible of the smelting slag is removed, and various BACKGROUND ART It has been widely practiced to improve the quality of products and stabilize operations.

Conventionally, the above-mentioned transfer of molten metal has been carried out using an operation method in which the tilting speed is kept as low as possible in order to suppress the outflow of smelting slag when the container is tilted. However, detection of smelting slag leakage is only done visually, and the flow rate of molten metal varies depending on the operator and even within the same person, so smelting slag inevitably remains or flows into a container for subsequent processing. In addition to poor accuracy, such as increased transfer time, heat loss, and longer molten metal processing time.

Various countermeasures have been devised to deal with this problem, such as installing a rotatable mechanical device (Japanese Utility Model Publication No. 13295/1983) at the outlet of the molten metal, so that the mechanical device hangs down as the container rotates, preventing slag from flowing out. There is a device. Since it is difficult to follow the hot water level, it is impossible to prevent the slag from flowing out from beginning to end. Furthermore, if the container is used repeatedly, it is highly conceivable that the slag may become inoperable due to the growth of smelting slag at the outlet. It is also understood that these devices cannot be sufficiently effective because there are no restrictions on shape, size, etc.

Another method uses the difference in specific gravity between molten metal and smelting slag (Japanese Patent Publication No. 47-20803). This method is a method for preventing slag outflow due to eddy flow during steel tapping from a converter. This is because the outlet of the container and the surface of the floating object come into contact only at the end, and the outlet is quickly blocked at the end, resulting in a large amount of residual pig iron remaining, causing a decrease in yield. Particularly when handling materials with good fluidity such as hot metal, the flow of the metal is fast, which can cause problems such as smelting slag overflowing onto the floating objects at the discharge port. Shape, dimensions, etc. must be determined.

In addition to the above-mentioned drawbacks, the followability to the hot water level was poor. Furthermore, there were shortcomings in equipment maintainability, running costs, and ability to follow various operational fluctuations. In particular, the thickness of the slag varies due to operational fluctuations.
The amount of adhesion to the outlet varies depending on the quality of the container.

Therefore, in order to solve the above problem, the shape and dimensions of the floating object in the width direction of the outlet, the shape of the rectangular parallelepiped,
There must be an optimal size and its limited range, such as the relationship between the size and the thickness of the slag layer and the thickness of the floating object, and those in the industry have always struggled with this point.

The present invention eliminates these shortcomings, specifically follows the diversity of recent operations, minimizes the prevention of smelting slag from flowing out from the vessel or smelting furnace, and reduces molten metal loss. The object of the present invention is to provide a floating object for preventing molten metal smelting slag from flowing out, which improves retention and saves energy by reducing transfer time.

(Means for Solving the Problems) A simple means for removing the slag remaining in the container or smelting furnace that achieves the above object of this invention is to provide a molten metal outlet 5 at one end of the upper part of the container 10, In the floating object 7 for preventing the molten metal from flowing out, the specific gravity is adjusted so as to span the interface between the molten metal 9 and the slag 8 in the container 10, and the floating object 7 is arranged so as to be in constant contact with the outlet 5. The floating object 7 is formed in the shape of a semi-ellipsoid, and the rectangular parallelepiped 4 is integrally provided at the center of the upper part of the semi-ellipsoid, and the ratio of the major axis B of the floating object 7 to the outlet width A is 1.2 to 1.2. 2.0, the ratio of the long side C of the rectangular parallelepiped to the major axis B is 0.5 to 1.0, and the ratio of the height H of the floating object 7 to the thickness h of the smelt slag is 1.0 to 2.0, respectively. It is a floating object to prevent spillage.

That is, as shown in FIG. 1, the cross section of the floating object 7 according to the present invention is a semi-ellipsoid, and the rectangular parallelepiped 4 is integrated with the upper part of the semi-ellipsoid. This rectangular parallelepiped 4 is also elongated in the width direction of the outlet. These are CaO・
Made of _SiO2 -based refractory. This rectangular parallelepiped 4 has the role of preventing smelting slag from overflowing from the container 10 or the smelting furnace when a large amount of smelting slag is generated. Further, two core metals 1 are built into the above-mentioned floating object so as to penetrate through the center of the semi-ellipsoid for specific gravity adjustment.

Next, the reasons for limiting each of the above-mentioned dimensions will be described.

First of all, the basic conditions necessary to achieve the purpose are as follows.

The first is that the bottom surface 13 of the floating object and the surface near the outlet of the refining furnace or container 10 come into surface contact and have an appropriate shape that can serve as a strong support.

Second, the size must be appropriate considering cost, workability, and main body strength.

In other words, in order to solve the above problem, the following 3 steps are required.
Two conditions are required.

Formed into a semi-ellipsoidal shape so that the bottom surface of the floating object and the surface around the outlet of the refining furnace or container are in surface contact,
Moreover, the ratio of the major axis B of the semiellipsoidal shape to the outlet width A is set to 1.2 to 2.0.

The ratio between the height H of floating objects and the thickness h of smelting slag is
Set to 1.0 to 2.0.

The ratio of the long side C of the rectangular parallelepiped that is integral with the upper part of the semiellipsoid to the long axis B of the semiellipsoid is 0.5 to 1.0.

The main reason why the floating object is formed into a semi-ellipsoidal shape as described above is to reduce the cost of refractories and to reduce the weight of the refractory, making it easier to manufacture, transport, and maintain.

In particular, the task cannot be achieved without the above ++. The reason will be explained later.

Next, the reasons for limiting the dimensions of A, B, and C will be explained in combination with the essential items listed above.

First of all, let's talk about it. If the ratio between the major axis B of the semi-ellipsoid and the outlet width A is less than 1.2, the width of the floating objects is too small and there is a high risk that they will flow out together with the smelting slag, whereas if it is larger than 2.0, this will lead to a significant increase in costs. Also, the appropriate range is 1.2 to 2.0 because the floating objects 7 come into contact with the two central locations of the container 10 and there are areas where the slag cannot be removed.

The following dimensional limitations will be discussed. floating object 7
The ratio between the height H and the slag thickness h is 1.0 to 2.0, which is the same as the ratio between the long axis B of the semiellipsoid and the outlet width A described above. That is, if this ratio becomes less than 1.0, the slag will overflow from the floating object 7 and the intended purpose will not be achieved. Moreover, if it exceeds 2.0, it will be too large and cause a loss in terms of cost. The limitation of the above ratio in the range of 1.0 to 2.0 is the actual value in actual operation. In other words, although the thickness of the slag varies depending on operational fluctuations, the above values are within a range that can substantially absorb the variation in the thickness of the slag.

The reason for the limitation is explained below. The long side C of the rectangular parallelepiped integrally formed on the upper part of the semiellipsoid and the long axis B of the semiellipsoid
If the ratio is less than 0.5, the reinforcing effect of the semi-ellipsoidal part will be small, and the floating objects will be damaged or cracked while being lifted into the container by a lifting device such as a crane, and the original purpose cannot be achieved. On the other hand, if it is larger than 1.0, surface contact at the outlet 5 of the semi-ellipsoidal container 10 becomes extremely difficult. That is, rectangular parallelepiped 4
If it is longer than the semi-ellipsoid, it will come into contact with two side walls of the container, and the above-mentioned surface contact will not be possible, but there will also be areas where the slag 8 cannot be removed. There is a problem, and it turns out that the above ratio is appropriate between 0.5 and 1.0.

Therefore, it can be seen that the above objectives cannot be achieved by each of them alone.

Next, consider combining the above ~.

First, let's consider the combination of +. This can achieve the intended purpose if there are no cracks or cuts in the cross-sectional direction of the floating object, but in actual use, + cannot be used, so the combination of + and + has been moved. .

In addition to what has been explained before, if only the above is adopted, if the ratio between the thickness h of the smelting slag and the height H of the floating object is less than 1.0, the smelting slag will overflow from the top of the floating object. and cannot achieve any effect.

For the above reasons, the desired purpose can only be achieved with ++.

Here, the shape of the floating object should be changed as appropriate depending on the properties of the molten metal or molten slag. For example, if the floating object shown in FIG. 4, which has grooves 6 on the bottom surface, is more effective. There is also.

(Function) The function when the floating object according to the present invention is used in the container 10 or the refining furnace is shown below with reference to FIGS. 2 and 3.

The floating object according to the present invention shown in FIG. 1 is placed in the vicinity of the metal container 10 or the outlet 5 of the smelting furnace using a lifting device such as a hoist so that it is always in surface contact with the object. At this time, the positions of the molten metal 9, the slag 8, and the floating objects in the height direction are such that they are suspended at a position midway between the molten pig iron and the slag due to the difference in specific gravity.

Under this condition, the container 10 or the smelting furnace is tilted at an appropriate speed, and the molten metal 9 that has passed through the lower end of the floating object 7 is continuously transferred to another container 11 while the rectangular parallelepiped 4 of the floating object prevents the smelting slag from flowing out. to be transferred. On the other hand, the slag 8 is stopped by the rectangular parallelepiped portion of the floating object 7, making it possible to prevent the slag 8 from flowing out.

In order to increase the effectiveness of removing the smelting slag 8, if the floating object shown in FIG. This will lead to improved yield.

(Example) A floating object according to the present invention was set at the outlet of a hot metal ladle, and the effect was confirmed by injecting it into a receiving container, which is a subsequent process, under the following operating conditions.

[Surrounding equipment conditions]

Γ Molten metal container...60 tons hot metal ladle Γ Transfer container...90 tons hot metal ladle Γ Transfer method...lifting equipment such as a crane [Operating conditions] Hot metal properties Temperature before transfer: 1310 to 1390℃ Ingredients ( %): [C] 4.53-4.97, [Si] 0.70-0.97,
[Mn] 0.50-0.69, [P] 0.043-0.072, [S]
0.012-0.021, [Cr] 0.019-0.029, [Ti] 0.016
~0.029 Refining slag component (%): [TFe] 6.0 ~ 15.5,
[CaO] 21.3-33.2, [ _SiO2 ] 29.4-34.8,
[MnO] 5.0 to 21.9 As a result of carrying out the experiment under the above equipment and operating conditions,
The amount of slag flowing out was 0.1 to 0.5 tons.

As a result, as shown in Figs. 5 and 6, it was possible to improve the yield by reducing the amount of rough pig iron generated and to reduce the transfer time by half, thereby saving energy.

Here, rough pig iron is what remains in the container or smelting furnace during transfer, and refers to a mixture of molten metal and smelting slag.

(Effect of the invention) When the floating object according to the invention is used, Fig. 2,
The work shown in FIG. 3 can be carried out smoothly, yields can be improved significantly, energy can be saved significantly, and costs can also be significantly reduced.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of a floating object for preventing smelting slag outflow according to the present invention, Figures 2 and 3 are sketches showing how it is used, and Figure 4 is an example of another shape according to the present invention. The figures shown in FIGS. 5 and 6 show the effects of the present invention as compared to the conventional method. 1... Core metal, 2... Refractory, 3... Upper surface of floating object, 4... Rectangular parallelepiped, 5... Outlet, 6... Groove, 7
... Floating object, 8 ... Smelting slag, 9 ... Molten metal,
10...Container, 11...Receiving container, 12...
Outflowing molten metal, 13... bottom of floating object.

Claims (1)

[Claims for Utility Model Registration] A molten metal outlet 5 is provided at one end of the upper part of the container 10, and the specific gravity is adjusted so that the outlet 5 always spans the interface between the molten metal 9 and the slag 8 in the container 10.
In the floating object 7 for preventing the outflow of smelting slag of molten metal, which is placed in contact with the floating object 7, the floating object 7 is formed in the shape of a semi-ellipsoid, and a rectangular parallelepiped 4 is integrated in the upper center of the semi-ellipsoid shape. The ratio of the major axis B of the floating object 7 to the outlet width A is
1.2 to 2.0, the ratio of the long side C of the rectangular parallelepiped to the major axis B is 0.5 to 1.0,
and a floating object for preventing smelting slag from flowing out of molten metal, characterized in that the ratio between the height H of the floating object 7 and the thickness h of the smelting slag is 1.0 to 2.0.