JPS5917166B2 - Gutter-like continuous deoxidizer - Google Patents

Description

[Detailed description of the invention] General (In this continuous steel manufacturing method, the molten steel that has undergone the continuous oxygen refining process contains a large amount of excess oxygen, and the slag is not separated sufficiently, so it is sent to the ingot making process. It is necessary to carry out deoxidation and component adjustment beforehand, but if these are carried out at the same time, there will be some practical inconvenience.

For example, additive alloy components (Fe-8i, Fe-Mn
etc.), and at the same time a large amount of deoxidized products are generated, significantly deteriorating the operability.

For this reason, molten steel has conventionally been deoxidized before the composition adjustment process, and the following devices are known as devices for continuously deoxidizing molten steel.

First, in the system shown in FIG. 1, molten steel and a deoxidizing agent are continuously supplied from one side of a trough-shaped deoxidizing container 01, and the molten steel is deoxidized as it moves through the deoxidizing container 01 as indicated by arrow a). When acid is carried out and the deoxidized steel flows out from the other side of the deoxidizing container 01 (arrow b), the slag 03 floating on the hot water surface is removed by the weir 02 located along the width direction of the deoxidizing container 01. This prevents the progress of deoxidation and separates it from the deoxidized steel.

As deoxidizing agents, ferrosilicon (Fe-8i), ferromanganese (F e -Mn ), or aluminum are usually used, and these react with oxygen in molten steel to produce S
Deoxidation products such as iO□, MnO, and Al2O3 are generated and float in the molten steel as inclusions 04.

These inclusions 04 gradually float to form the slag 03 on the molten metal surface, but since the floating speed is not uniform, the inclusions 04 in the molten steel are placed on the steel receiving side of the weir 02 in order to be sufficiently separated and removed. A so-called sedation period 05 is required.

Since this calming zone 05 is open upward over a wide area, the slag 05 spreads widely over the hot water surface, and the deoxidizing container 01
It becomes difficult to remove the slag from the end (arrow C) and there is a large amount of heat dissipated from this part, and furthermore, oxygen in the air enters the molten steel through the slag in the sedation zone 05 and reoxidizes the molten steel. This is extremely undesirable from a practical point of view.

Therefore, as shown in Fig. 2 ζ, an apparatus was developed in which a horizontal layer 06 is used as a weir to prevent the advance of slag 03, and the surface of the molten steel in the portion corresponding to the calming zone 05 is covered by the horizontal layer 06ζ. In this case, although the reoxidation and heat dissipation of the molten steel are reduced, the inclusions 04 floating from the molten steel accumulate on the lower side of the horizontal layer 06 and form a slag accumulation layer 07, making it extremely difficult to remove the slag. Not suitable for practical use.

The present invention covers the calming section with a weir and guides the inclusions in the molten steel to the steel receiving side, making slag removal extremely easy. A trough-like continuous deoxidizer that separates the deoxidized products from the molten steel by blocking the progress of the deoxidized products floating on the surface of the molten metal with a weir while the molten steel supplied to the molten steel advances to the tapping port of the trough-like container. In this method, the outer bottom surface of the weir is formed into a slope that gradually lowers along the direction of progress of the molten steel, and a gas outlet for blowing an inert gas into the molten steel is provided at approximately the lower end of the slope. The present invention is characterized in that the deoxidized products in the molten steel are floated along the inclined surface toward the steel receiving side.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The trough-like continuous deoxidizing device according to the present invention will be explained in detail with reference to an embodiment shown in the drawings.

The deoxidizing container 1 has a gutter shape and is installed substantially horizontally.

The deoxidizing container 1 is provided with a steel receiving port 2 and a steel tapping port 3 at both ends, respectively, and molten steel (unoxidized steel) charged from the steel receiving port 2 advances through the container 1 and passes through the steel tapping port. The molten steel is deoxidized by the time it reaches step 3.

For this purpose, the container 1 is provided with a gradient layer 4.

The inclined layer 4 covers the entire width of the container 1 and divides the inside of the container 1 into a steel receiving side and a steel tapping side.

The inclined layer 4 is composed of an inclined wall 4a, a weir portion 4b, and a rear wall 4C, and the inclined wall 4a is inclined so as to be gradually lowered along the traveling direction of the molten steel traveling inside the container 1.

The weir part 4b is formed to protrude above the hot water surface from the upper end of the inclined wall 4a to prevent the advancement of slag on the hot water surface, while the rear wall 4C is formed to protrude above the hot water surface from the lower end of the inclined wall 4a. This prevents molten steel from flowing above the inclined wall 4a.

Further, the lower end of the inclined layer 4 is located above the bottom surface of the deoxidizing container 1, and the molten steel flows from the steel receiving side to the tapping side through the space between the inclined layer 4 and the bottom surface of the container 1. proceed.

The molten steel that has reached the tapping side continuously flows out from the tapping port 3 (arrow B).

The steel receiving side end of the deoxidizing container 1 and the front end of the inclined layer 4 (
The part between the weir part 4b) is opened upward, and this opening part becomes the steel receiving port 2 to which molten steel is supplied.

In this embodiment, a chute 5 is positioned above the steel receiving port 2, and together with the molten steel device (arrow A), the deoxidizing agent 6 is charged into the steel receiving port 2 from the chute 5. do.

Furthermore, a slag discharge lower is formed at the steel receiving side end of the deoxidizing vessel 1 for discharging slag on the surface of the hot water.

The slag discharge lower is provided at a slightly higher position than the tap port 3 formed at the tap side end of the vessel to avoid natural outflow of molten steel and to transport the slag 8 on the surface of the molten metal to the slag lower. (In the direction of arrow C) Place it in a position where it can be easily scraped out.

Further, it is desirable that the steel receiving port 2 has a small area to the extent that charging of molten steel and deoxidizing agent 6 is not hindered.

In this case, the layer thickness of the slag 8 that accumulates on the hot water surface of the steel receiving port 2 increases and it becomes easier to scrape out the slag 8.
The risk of heat dissipation through the layers and re-oxidation of the steel is substantially reduced.

Furthermore, a gas outlet 9 for blowing inert gas into the molten steel is provided at the substantially lower end of the inclined surface of the inclined layer 4, that is, the lower surface of the inclined wall 4a.
is provided to form a continuous deoxidizer.

The gas outlet 9 connects the tip of the gas supply pipe 10 to the inclined wall 4.
The inclined wall 4a is formed by penetrating through the opening ζ below the inclined wall 4a,
Alternatively, a porous plug (not shown) may be attached to the inclined surface by connecting the gas supply pipe 10 to the porous plug.

The inert gas blown into the molten steel from the gas outlet 9 rises along the inclined surface and is discharged from the steel receiving port 2 to the outside of the container 1.

This gas blowing is to prevent inclusions 11 in the molten steel from adhering to the inclined surface, and it is desirable to form an inert gas flow over the front surface of the inclined surface.

Note that the amount of gas blown is appropriately set to such an extent that the inclusions 11 do not adhere to the inclined surface.

The size of the inclined layer 4 is set so that a sufficient calming section 12 is secured between the steel receiving port 2 and the gas outlet 9.

In this case, the surface of the molten steel in the calming zone 12 is covered by the inclined wall 4a to avoid reoxidation of the molten steel and heat dissipation, and the deoxidation products (inclusions 11) generated in the molten steel are removed from the deoxidation container 11.
Before reaching the tapping side, the slag floats up to the inclined surface, is raised along the inclined surface by the inert gas flow, and accumulates on the molten metal surface of the steel receiving port 2 to form the slag 8.

The deoxidizing container 1 and the inclined layer 4 are preferably formed of an iron plate lined with a refractory material.

The continuous deoxidizing device has a continuous oxygen refining furnace 13 shown in FIG.
The molten steel tapped from the molten steel is supplied.

In the continuous oxygen refining furnace 13, oxygen is blown into the hot metal Q injected from the inlet 14 through the water cooling lance 15 to perform oxygen refining of the hot metal, and molten steel containing a large amount of excess oxygen is continuously tapped. .

When this molten steel is continuously charged into the continuous deoxidizer ζ, a deoxidizer 6 is also charged from the chute 5.

As the deoxidizing agent 6, ferrosilicon (F e -S i
), ferromanganese (Fe-Mn), or aluminum wire, etc., and these deoxidizers 6 can be used in the deoxidizer container 1.
Reacts with oxygen in the molten steel to form 5i02゜MnO,
A deoxidizing product such as AIE 20s is generated to deoxidize the molten steel.

The deoxidized products are suspended in the molten steel as inclusions 11, but most of them gradually float up to form slag 8 on the surface of the steel receiving port 2.

Some of the inclusions 11 have a slow floating speed and advance in the deoxidizing container 1 together with the molten steel, but as described above, a sufficient calming section 12 is provided so that the inclusions 11 are removed before reaching the tapping side. O
The slag 8 reliably floats up to the inclined surface and is transported to the steel receiving side by the inert gas flow formed along the inclined surface to form the slag 8.

This slag 8 is prevented from advancing by the weir portion 4b of the inclined layer 4, and therefore only deoxidized molten steel enters the tapping side.

The molten steel (deoxidized steel) deoxidized by the deoxidizer 6 and separated from the deoxidized products by the inclined layer 4 reaches the tapping side of the deoxidizing container 1 and continuously flows out from the tapping port 3. do.

This deoxidized steel Oζ, for example, a composition adjustment furnace as shown in FIG.
In other words, the composition may be adjusted by introducing it into an induction furnace 17 equipped with a heater 16.

On the other hand, the slag 8 accumulated in the steel receiving port 2 of the deoxidizing container 1 is discharged from the slag discharge lower.

In this case, since the steel receiving port 2 has a relatively small area and the slag 8 is accumulated in a thick layer, it is very easy to scrape out, and there is a risk that the molten steel may be reoxidized or heat dissipated through the layer of the slag 8. There are hardly any.

Note that the surface of the molten steel corresponding to the calming zone 12 is the slope layer 4.
is covered, so the re-oxidation and heat dissipation described above do not occur in the calming section unlike in the conventional case.

As described above, the continuous deoxidizing device according to the present invention not only ensures reliable separation of deoxidized products, but also allows very easy removal of slag and eliminates reoxidation of molten steel and heat dissipation. This can be reliably prevented and has extremely beneficial effects in practice.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a conventional trough-like continuous deoxidizer; FIG. 2 is a schematic cross-sectional view showing a continuous deoxidizer equipped with a horizontal layer;
FIG. 3 is a schematic cross-sectional view showing a trough-like continuous deoxidizing device according to the present invention, and FIG. 4 is a schematic cross-sectional view showing a part of a continuous steel manufacturing process using the device. In the drawings, 01 is a deoxidizing container, 02 is a weir, 03 is a slag, 04 is an inclusion, 05 is a calming section, and 06 is a horizontal layer. 07 is a slag accumulation layer, 1 is a deoxidizing container, 2 is a steel receiving port, 3 is a steel tapping port, 4 is a sloped layer, 4a is a tilted wall, 4b is a weir, 4c
is the rear wall, 5 is the chute, 6 is the deoxidizer, 7 is the slag outlet, 8 is the slag, 9 is the gas outlet, 10 is the gas feed pipe, 11 is the inclusion, 12 is the calming section, 13 is continuous An oxygen refining furnace, 14 is a metal inlet, 15 is a water cooling lance, 16 is a heater, and 17 is an induction furnace.

Claims (1)

[Claims] 1. While the molten steel supplied to the steel receiving port of the trough-shaped container advances to the tapping port of the trough-shaped container, the progress of the deoxidized products floating on the surface of the molten metal is blocked by a weir, and the deoxidized products are converted into molten steel. In the separating gutter-like continuous deoxidizing device, the outer bottom surface of the weir is an inclined surface that gradually decreases along the traveling direction of the molten steel (inert gas is blown into the molten steel approximately at the lower end of the inclined surface). Provide a gas outlet,
A trough-like continuous deoxidizing device characterized in that the blown gas causes the deoxidized products in the molten steel to float along the inclined surface toward the steel receiving side.