JPH0619966U - Porous nozzle for molten metal container - Google Patents

Abstract

(57) [Summary] The present invention relates to an upper nozzle for a molten metal container, wherein an outer peripheral surface of the upper nozzle is surrounded by a metal casing (10), and an axial direction is provided on an inner peripheral side of a molten steel flow hole (20). 1/2 of
The above is constituted by a porous brick (9), and the outer periphery, upper part and lower part of the porous brick (9) are surrounded by castable refractory (8), and between the porous brick (9) and the castable refractory (8). A feature is that an inert gas pool (11) is provided between the axial planes and the inert gas is supplied to the pool (11). [Effects] With such a technical configuration, it is possible to provide a porous nozzle that does not impair the sealing property even when it becomes high temperature molten steel and is continuously operated for a long time.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a porous nozzle capable of discharging an inert gas such as nitrogen or argon from the surface of the nozzle inner hole.

[0002]

[Prior art]

 In a tundish that controls the flow rate of molten metal using a slide valve device, the upper nozzle (insert nozzle) prevents solidification when molten metal such as molten steel is injected and clogs alumina (alumina-based inclusions adhere to the nozzle inner hole). Porous nozzles that can discharge inert gas such as nitrogen and argon from the inner surface of the nozzle inner hole are used to prevent nozzle clogging caused by the above.

A conventional porous nozzle will be described with reference to FIGS. 2 to 4. In the porous nozzle shown in FIG. 2, the outer peripheral surface of the porous brick 1 is surrounded by an iron plate case 2, a space 3 is provided between the outer peripheral surface of the porous brick 1 and the iron plate case 2, and an inert gas supply pipe 4 is provided. Is connected to the iron plate 3. In the porous nozzle shown in FIG. 3, a narrow gap 5 is provided inside the porous brick 1, and an inert gas supply pipe 4 penetrating the iron plate case 2 is communicated with this gap 5. Further, in the porous nozzle shown in FIG. 4, the outer circumference of the porous brick 1 is surrounded by the iron plate case 2, and the space 3 is provided between the lower part of the iron plate case 2 and the lower part of the porous brick 1. Then, the inert gas supply pipe 4 is connected to the iron plate case 2 so as to communicate with the space 3. A circular groove 6 is formed on the outer peripheral surface of the upper portion of the porous brick 1, and a plurality of vertical grooves 7 are formed around the side of the porous brick 1 so as to connect the circular groove 6 and the space 3 (actual opening 60- 56150).

[0004]

[Problems to be solved by the device]

 In each of the conventional porous nozzles as described above, the outer peripheral surface of the porous brick of the inert discharge portion is directly surrounded by the iron casing. For this reason, the gas seal on the side peripheral surface of the porous brick is held by the iron casing and a mortar or sealing material with a thickness of several mm or less filled between the casing and the porous brick.

Recently, in a tundish, molten steel is heated by a plasma torch, an electromagnetic heater, an induction current or the like, and the temperature around the upper nozzle tends to be higher than before. In this case, in the porous nozzle having the above-described known structure, the temperature rise of the iron casing causes thermal expansion or deformation of the casing, which causes a problem that sufficient sealing performance cannot be maintained.

[0006]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present inventors have developed the present invention as a result of various studies and experiments, and the technical configuration of the present invention is the upper nozzle for a molten metal container, The outer peripheral surface of the nozzle is surrounded by a metal casing (10), and half or more in the axial direction on the inner peripheral side of the molten steel flow hole (20) is made of porous brick (9). The outer circumference, the upper part and the lower part are surrounded by castable refractory (8), and an inert gas spool (11) is provided between the porous brick (9) and the castable refractory (8) in the axial direction, and the pool ( 11) is characterized by supplying an inert gas, and by adopting such a technical configuration, a porous nozzle that does not deteriorate the sealing property even if it becomes high temperature molten steel and is continuously operated for a long time. Can be provided.

[0007]

[Action]

 In the porous nozzle of the present invention, the peripheral portion of the porous brick of the inert gas discharge part other than the molten steel contact surface is surrounded by the castable refractory, and the molten steel is heated by the plasma torch, electromagnetic heater or induction current. Even if the iron casing expands or deforms due to the temperature rise of the molten steel near the porous nozzle, the outer circumference of the porous brick is surrounded by castable refractory, so that the inert gas injection continues for a long time. You can

Detailed description will be given with reference to FIG. 1 which is a vertical sectional view of one embodiment of the present invention.

In FIG. 1, reference numeral 9 denotes a porous brick, which is arranged on the inner peripheral side of the molten steel flow hole 20 over a half or more of its axial direction. Reference numeral 8 denotes a castable refractory, which surrounds the outer circumference, the upper part and the lower part of the porous brick 9 and an inert gas pool 11 is provided between the porous brick 9 and the axial surface of the castable refractory outside the porous brick. It is installed all around. Further, an inert gas can be supplied to the inert gas pool 11 by an inert gas supply pipe 12 from an inert gas supply source (not shown).

The castable refractory is surrounded by an iron casing 10 as shown in the drawing.

[0011]

[Effect of device]

 As described above, according to the porous nozzle of the present invention, the gas sealing property of the porous brick is continuously maintained even if the temperature around the upper nozzle rises due to the molten steel heating in the tundish by the plasma torch, electromagnetic heater or induction current. There will be things to do.

Therefore, conventionally, the gas sealability is impaired as the casting time elapses, alumina-based inclusions adhere to the molten steel flow holes of the porous nozzle, causing nozzle clogging, and continuous operation for a long time is required. However, such problems can be reliably prevented and the continuation of operations can be extended.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a specific example of the mechanism of the present invention.

FIG. 2 is a vertical sectional view showing an example of a conventional mechanism.

FIG. 3 is a vertical sectional view showing an example of a conventional mechanism.

FIG. 4 is a vertical sectional view showing an example of a conventional mechanism.

[Explanation of symbols]

 8 Castable refractories 9 Porous bricks 10 Iron casing 11 Inert gas pool 12 Inert gas supply pipe

Claims (1)

[Scope of utility model registration request] 1. In an upper nozzle for a molten metal container, an outer peripheral surface of the upper nozzle is surrounded by a metal casing (10), and a half or more of the axial direction on the inner peripheral side of the molten steel flow hole (20) is a porous brick. (9) Comprising the porous brick (9)
The outer periphery, the upper part and the lower part of the are surrounded by castable refractories (8), and an inert gas pool (11) is provided between the porous bricks (9) and the castable refractories (8) in the axial direction, and the pool is formed. A porous nozzle for a molten metal container, characterized in that an inert gas is supplied to (11).