JPH0576656U - Tundish upper nozzle - Google Patents

Abstract

(57) [Abstract] [Purpose] To eliminate alumina precipitation and continuous drop in casting number due to the fact that gas discharge on the gas introduction hole side is much larger than on the gas introduction hole side in actual operation. [Structure] In a tundish upper nozzle for blowing an inert gas as a measure for preventing clogging of the tundish upper nozzle, an outer peripheral skin 2 and a porous body 1 of the nozzle body are provided.
The cross-sectional area of the annular gas pools 3 and 3'which are connected to each other or in communication with the inside of the porous body 1 are partially different so that the gas introduction hole 5 is narrow and the non-gas introduction hole side is wide. It has a feature. [Effect] It has become possible to make the uniform gas dispersibility from the nozzle holes uniform. Further, in the recent low-flow rate gas blowing (low pressure blowing) operation in steelmaking, it is possible to blow gas uniformly from the entire nozzle hole, and good results can be obtained.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tundish upper nozzle used in a tundish in continuous casting for producing steel.

[0002]

[Prior Art]

 Conventionally, gas bubbling using an upper nozzle has been widely practiced as a measure to prevent nozzle clogging due to the precipitation of inclusions such as alumina as a refractory for SN.

[0003]

[Problems to be solved by the device]

 As shown in FIGS. 1 to 4, the conventional tundish upper nozzle communicates with the annular gas pool 3 installed between the porous body 1 and the outer peripheral iron shell 2 covering the porous body 1 or the inside of the porous body 1. The annular gas pools 3'provided are arranged concentrically with respect to the nozzle holes 4, respectively. In this case, the cross-sectional areas of the gas pools 3 and 3'in FIGS. 1 to 4 were xy = xy 'and xz = xz' when χ was constant.

In this case, due to the porous material of the porous body 1, in actual operation, gas discharge on the gas introduction hole 5 side is much larger than on the anti-gas introduction hole side, which is a factor of alumina precipitation, This is a factor that causes the number of castings to drop.

[0005]

[Means for Solving the Problems]

 The present invention has been made to solve the above problems, and is configured as follows.

That is, the tundish upper nozzle of the present invention is a tundish upper nozzle for blowing an inert gas as a measure for preventing clogging of the tundish upper nozzle. Alternatively, it is characterized in that the cross-sectional area of the annular gas pool connected in communication inside the porous body is made partially different so that the gas introduction hole side is narrower and the anti-gas introduction hole side is wider.

In short, the tundish upper nozzle of the present invention is a gas pool 3 installed between the porous body 1 and the outer peripheral iron shell 2 covering the porous body 1 as shown in FIGS. A gas pool 3'installed inside the porous body 1 has a cross-sectional area of xy <xy ', xz <xz', which is a tundish upper nozzle.

[0008]

[Effect of the device]

 The effects of the present invention will be described with reference to examples.

[0009]

【Example】

 In the present invention, the nozzle shown in FIGS. 5 to 8 was prototyped, the prototype and the conventional product were set in a water tank filled with water, and the gas discharge amount was visually confirmed, and as shown in Table 1 below. I got good results.

[0010]

[Table 1]

From the above results, it was confirmed that in this example, by setting y <y ′ and z <z ′, uniform gas dispersibility from the nozzle holes 4 can be made uniform. .. It is clear that, in the recent small-flow gas injection (low-pressure injection) operation in steelmaking, uniform gas injection from the entire nozzle hole is possible and good results are obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an example of a conventional tundish upper nozzle.

FIG. 2 is a vertical cross-sectional view of another embodiment of a conventional tundish upper nozzle.

FIG. 3 is a cross-sectional view of a conventional tundish upper nozzle embodiment.

FIG. 4 is a cross-sectional view of another example of a conventional tundish upper nozzle.

FIG. 5 is a vertical sectional view of an embodiment according to the present invention.

FIG. 6 is a vertical cross-sectional view of another embodiment according to the present invention.

FIG. 7 is a cross-sectional view of an embodiment according to the present invention.

FIG. 8 is a cross-sectional view of another embodiment according to the present invention.

[Explanation of symbols]

 1 Porous body 2 Outer peripheral skin 3 Gas pool 3'Gas pool 4 Nozzle hole 5 Gas introduction hole

Claims (1)

[Scope of utility model registration request] As a measure to prevent clogging of the tundish upper nozzle, in the tundish upper nozzle for blowing in inert gas, traverse an annular gas pool that is connected between the outer peripheral skin and the porous body part of the nozzle body or inside the porous body. A tundish upper nozzle characterized in that the areas are partially different so that the gas introduction hole side is narrower and the anti-gas introduction hole side is wider.