JPS6068143A - Gas sealing method of porous refractories - Google Patents

Abstract

PURPOSE:To prevent thorough gas leakage by forming an annular fitting zone to serve as a contact boundary layer between the outside circumferential surface in the upper part of porous refractories and a shell or shell fixing member thereby assuring tightness with the annular fitting zone. CONSTITUTION:A stage of an annular groove 8 is provided to the outside circumferential surface in the upper part of porous refractories 1 and the part near the top outside circumferential end of the refractories 1 is coated with a sealant 2 to prevent dissipation of gas to the outside. The lower part that contacts with the sealant 2 is enclosed with a shell 4 down to the bottom end of the refractories 1 and a space is provided around the body of the shell to form a gas pool chamber 3. The top edge of the shell 4 is welded to a set ring 6 fitted to the groove 8 to form an annular fitting zone 10 and to prevent gas leakage from the chamber 3. A labyrinth effect is increased and the gas leakage is thoroughly prevented if the groove 8 is formed into three stages and the zone 10 united by welding with the shell 4 and the ring 6 is made into 3 stages of zigzag constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention effectively prevents penetration and solidification of molten steel and agitates molten steel when using porous refractories such as porous nozzles attached to the upper part of sliding nozzles for ladle or tundish. This relates to a gas sealing method for preventing the leakage of blown gas for use in air-conditioning operations.

Conventionally, gas seals for porous refractories, such as porous nozzles, are formed between the iron sheathing used and the outer circumferential surface of the nozzle. It is customary to fill the gap with mortar to seal the gas. However, in such a method, once heated, the mortar shrinks and deforms, resulting in a seal failure and gas leakage. If gas leaks from the outer circumferential surface of the nozzle, stable gas blowing through the inner circumferential surface of the porous nozzle will not be possible, and the desired amount of gas ventilation will not be obtained, and molten steel will enter the porous nozzle and solidify, causing the molten steel to have sufficient flow. In some cases, stirring is insufficient and it becomes difficult to flow, and the problem has been a decrease in operational efficiency due to failure of gas injection, which is the original purpose of porous refractories.

The present invention was made in consideration of the current situation, and includes a structure between the upper outer circumferential surface of the porous refractory and the inner circumferential upper edge or upper end of the iron shell.
The object of the present invention is to provide a gas sealing method that forms an annular band that can withstand thermal shock and maintain a close contact state, and that can completely prevent gas leakage with this annular band.

Hereinafter, one embodiment of the method of the present invention will be described. An annular fitting band is formed on the upper edge or end of the steel shell by appropriate means, and between the inner surface of the steel shell and the upper outer circumferential surface of the porous refractory. This is a gas sealing method that aims to provide a structure that has high thermal shock resistance brought about by the zigzag contact layer that occurs in the zigzag contact layer and high sealing performance due to the labyrinth effect.

Next, to give specific examples of the various methods of the present invention, first, as shown in FIG. 1 or FIG. An annular groove is carved, a metal ring with a circular or polygonal cross section is wound around the annular groove to form a set ring, and the inner periphery of the upper edge of the iron shell is welded to this to surround the porous nozzle. The upper part of the iron skin, which forms a gas pool chamber between the outer peripheral surface of the nozzle and the upper part of the porous nozzle, is in contact with the upper part of the porous nozzle, and this appears to be a zigzag contact surface, which contributes to preventing gas leakage. Fig. 1 is a vertical cross-sectional view of a specific example in which only one stage of annular groove (8) is provided on the upper outer circumferential surface of the porous refractory (1), and the upper edge of the outer circumference of the porous refractory (1) is covered with sealing material. (2) to prevent gas from escaping from this part to the outer periphery, and the lower part in contact with the sealing material (2) is surrounded by an iron skin (4) up to the lower end of the porous refractory (1). A gap is maintained between the outer circumferential surface of the porous refractory (1) and the inner circumferential surface of the iron shell (4) in the shell circumference, and the gas pool chamber (3) surrounding the porous refractory (1) is Form. (5) is the gas pool room (3)
The upper edge of the steel shell (4) is welded to the set ring (6) fitted in the annular groove (8) to form an annular fitting band Ql, and the gas pool chamber is (3) This effectively prevents gas leakage from occurring without loss of function due to thermal shock. Figure 2 shows an example of a three-stage annular groove (8) carved in a porous refractory (1), and an annular fitting zone in which the iron skin (4) and set ring (6) are welded together. α
Q has a three-stage zigzag structure with the outer peripheral surface of the porous refractory (1), increasing the labyrinth effect and completely preventing gas leakage from this part.

Since such a structure is obtained according to the method of the present invention, the contact layer between the outer surface of the porous refractory and the inner surface of the steel skin has an apparent upper zigzag structure, so that the molten steel passes through or the molten steel does not pass during steel receiving. Even if the porous refractory is heated when gas is injected into it, the occurrence of gaps due to cracks or defects between the iron skin and the porous refractory is prevented, and furthermore, this annular fitting band protects the core. Because it exerts a labyrinth effect on the gas that is to be distributed, gas leakage from the outer surface of the porous refractory does not occur, and gas is stably blown out from the inner surface of the porous refractory, such as a porous nozzle, preventing penetration of molten steel and It prevents solidification and allows sufficient stirring of molten steel.

In addition, in order to form an annular fitting zone with a zigzag cross section near the upper edge of the steel shell, as shown in Figure 3, depending on the relationship between the compositional strength of the porous refractory and the thickness of the steel shell, etc. , 3rd
As shown in Figure (a), for example, an annular groove (8) is provided around the upper outer periphery of a porous nozzle, mortar (9) is applied in this groove, and an iron skin (4) is formed to cover the annular groove (8). be fitted. Then, as shown in Figure 3), pressure is applied to the part of the iron skin (4) that corresponds to the annular groove (8), and the iron skin (4) is removed.
If it is squeezed into the annular groove (8), the previously applied mortar (9) will fit into the annular groove (8) carved in the porous nozzle.
Fill the gap between the bottom and side walls of the iron shell and the narrowed part of the steel shell,
The annular fitting band α0 becomes an effective gas seal.

As another specific example, one or more grooves α are carved on the inner peripheral surface of the iron skin (4), as shown in FIG. 4 when the inner surface of the iron skin is developed. As shown in the figure, a means for attaching a protrusion (6) such as a square bar to the inner peripheral surface of the iron skin (4) can also be adopted. When fitting the steel skin (4) into the porous refractory, it is carved with grooves (0) or protrusions (2).
) If mortar is filled between the grooves, the ridges or protrusions between the grooves will form an annular fitting zone αO with an apparent zigzag cross section, similar to the above specific example, It has excellent thermal shock resistance and exhibits excellent gas sealing effects.

In the above specific example, an annular fitting zone is formed on the upper part of the steel shell, which becomes a contact layer where the steel shell or the steel shell fixing member and the outer circumferential surface of the refractory intersect in a zigzag manner. A similar annular inset can be formed in the lower part of the skin.

The above is a description of a specific example based on the method of the present invention using a porous nozzle as an example. However, the gas sealing method of the present invention can be applied to porous refractories with a gas blowing function, including porous plugs, to achieve its effects. It goes without saying that anything that can be obtained by means according to the scope of the claims falls within the technical scope of the present invention.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory views of one embodiment of the method of the present invention. Figure 1 is a specific example in which one stage of annular fitting band is provided, Figure 2 is a specific example in which three stages are provided, and Figure 3 ( a) is the processing state of another specific example,
Φ) is a diagram showing a state in which an annular fitting band is formed,
FIGS. 4 and 5 are exploded views of the upper end of the steel shell in another specific example. (1)... Porous refractory (2)... Sealing material (
3)...Gas pool room (4)...Iron skin (5)...
Gas introduction pipe (6)...Set ring (7)...Nozzle hole (8)...Annular groove (9)...Mortar 0
0...Annular fitting band α◇...Groove @...Protrusion Fig. 7 Fig. 3 (a) (b)

Claims (1)

[Claims] The inner circumferential surface of the refractory/object and other required areas are exposed for gas blowing, and the outer circumferential side and main parts of the bottom are made of iron skin with a constant distance from the outer surface of the refractory to form a gas pool chamber. In porous refractories that are encased and the remaining part is covered with a sealing material and injected with gas, there is an annular fitting zone that serves as a contact boundary layer where the shell or the shell fixing member and the outer circumferential surface of the refractory are intertwined in a zigzag manner. Gas of a porous refractory, characterized in that the upper outer circumferential surface of the porous refractory body and the upper edge of the inner periphery of the iron skin or the vicinity of the upper edge are brought into close contact so as to maintain high sealing performance. Seal method.