JPH0123229B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a sliding nozzle device (hereinafter referred to as SN).
In order to prevent the oxidation of SN plate bricks containing one or more of carbon, carbides, hydrocarbons, and non-oxides due to air entering from the sliding surfaces in This invention relates to a gas seal mechanism that supplies an inert gas atmosphere between sliding surfaces to create an inert gas atmosphere.

In the molten steel casting method, a method is used to control the flow rate by sliding a refractory plate with holes, and the materials for the refractory plate include scaly graphite, carbon black, silicon carbide, tar, and pitch, which have excellent corrosion resistance and spalling resistance. Carbon-containing materials blended with or impregnated with synthetic resins or non-oxidizing materials such as silicon nitride are used.

However, between the sliding surfaces of the SN plate, outside air is sucked in by the flow of molten steel from local gaps caused by roughness and local expansion of the sliding surfaces due to wear and tear during use, or cracks in the plate bricks. Combined with the high temperature in the surrounding area, a problem occurred in which the carbon in the plate bricks was oxidized, further promoting roughening of the sliding surfaces and nozzle hole edges.

Therefore, in the present invention, nitrogen is constantly and continuously applied to the sliding surface.
The purpose is to prevent carbon oxidation in the plate bricks by creating an inert gas atmosphere in the gap between the sliding surfaces by purging with an inert gas such as argon or carbon dioxide. On the sliding surface, inert gas is placed around the base material of the sliding nozzle plate, which is surrounded and protected by a metal band to enable the supply of inert gas from the gas permeable body around the molten metal flow holes. A gas permeable body is integrally provided as a medium for supplying and filling the sliding surface with gas, and a gas sealing material is interposed between the gas permeable body and the metal strip. It is something.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 1 shows an example of an SN device using a three-plate system, in which a gas permeable body 5 is provided around the plate base material of an upper fixed plate 1, a sliding plate 2, and a lower fixed plate 3. 5 is provided with a gas distribution groove 6 that communicates with a gas introduction device (not shown) from the outside beyond a holding frame (not shown) held on the SN plate device in order to equalize the gas supply. There is. Reference numeral 7 denotes a gas sealing material, which is preferable because it serves to maintain airtightness between the metal strip 8 and the gas permeable body 5, which will be described later. 8 is a metal band plate. 4 is a molten metal flow hole common to each plate. The state shown in the figure is the state of the molten metal flow hole, but the area around the flow hole is an inert gas atmosphere.

FIG. 2 is a plan view of the plate shown in FIG. 1.

Regarding the structure of the gas permeable body 5, a portion of the upper fixed plate 1 and the lower fixed plate 3 other than the sliding surfaces may be continuously constructed of the plate base material 9. Further, for each plate, the base material 9 may be partially continuous up to the sealing material 7, and such a structure is preferable in terms of plate structural strength.

Furthermore, since the gas is ejected from the gas permeable body 5, the gas can be evenly supplied between the sliding surfaces.

A method of setting a fired product or an unfired product on the plate base material 9 as the gas permeable body 5;
Possible methods include a method of simultaneous molding with a metal strip 8 and a method of casting a composition made of an amorphous refractory material.
SN has become a single entity.
If the plate base material 9 suffers from melting or cracking, the plate can be easily replaced within the holding frame of the SN device (not shown). The present invention prevents outside air from being sucked in between the SN sliding surfaces, prevents carbon oxidation in the plate bricks, and prevents oxidation of the non-oxide base material, contributing to extending the life of the SN plate bricks. It also helps prevent molten steel from oxidizing by drawing outside air into the molten steel.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal cross-sectional view of a three-plate type SN device in which the present invention is implemented, and FIG. 2 is a plan view thereof. 1...Top fixed plate, 2...Sliding plate,
3... lower fixing plate, 4... molten metal flow hole,
5... Gas permeable body, 6... Gas distribution groove, 7... Gas sealing material, 8... Metal strip plate, 9... Plate base material.

Claims (1)

[Claims] 1.A gas permeable body as a medium for supplying and filling the sliding surface with inert gas is integrally provided around the plate base material of the sliding nozzle plate that is surrounded and protected by a metal band, and the gas permeation body is A gas sealing mechanism between plate brick sliding surfaces of a sliding nozzle device, characterized in that a gas sealing material is interposed between a penetrating body and a metal strip.