JPH0116235B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of an insert type plate refractory in a sliding nozzle device.

Conventionally, insert-type plate refractories have been known in which a corrosion-resistant refractory is attached to the molten metal discharge port that comes into contact with the molten metal in order to improve the corrosion resistance of the plate refractories for sliding nozzle devices. It is being

The resistance of this insert-type plate refractory to molten metal is determined by the characteristics of the insert refractory. For example, zirconia is known as an excellent material, but in recent years plate refractories have As the size increases, the difference in thermal expansion,
Price and other factors have come to appear as factors that cannot be ignored.

In other words, conventional insert-type plate refractories basically consist of a material 1 that has high corrosion resistance against molten steel, slag, etc., arranged around the molten metal outlet, as shown in Figure 1a and b. This is set on a fired refractory plate 2 using mortar 3, and various materials and structures are known.

However, due to the generation of abnormal stress due to the difference in thermal expansion between different materials, the application of surface pressure, and mechanical external forces applied to the plate such as sliding, the mortar adhesive surface comes off, causing the insert to protrude or fall, and the molten metal discharge port This often led to problems such as chipped edges, uneven surface pressure, and metal inserts.

This invention improves the drawbacks of such insert-type plate refractories.The part that comes into contact with molten metal is made of a highly corrosion-resistant material and is used as a central member, and the peripheral side of this central member is provided with a plate. A fastening fitting having a width narrower than the thickness of the refractory and having a cooling gas passage on the outer periphery is tightly fitted, and this is integrally cast with a castable refractory to form a plate refractory.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2a is a plan view of a plate refractory showing an embodiment of the present invention, in which a central member 5 having an outlet 4 through which molten metal passes is a fired refractory whose main component is zirconia. As shown in the longitudinal cross-sectional view of FIG. 2b, a fastening fitting 8 having a width narrower than the thickness 7 of the plate refractory 6 is fitted onto the circumferential side of the central member 5 by shrink fitting or other methods. There is. A cooling gas passage 14 made of a previously welded metal pipe is provided on the outer surface of the fastening fitting 8, and a V-shaped stud 9 or the like is further welded thereto. The cooling gas passage 14 is a cooling mechanism that prevents the fastening metal 8 from being heated and expanded by the temperature of the molten metal and reducing the fastening force.
Cooling gas such as air or inert gas is circulated around the fastening fitting 8 from a ventilation hole 13 provided on the side surface of the plate refractory 6 . This is set as the central member 5, and a high alumina castable refractory is poured in as the outer peripheral member to form the plate refractory 6. If necessary, a hoop 10 may be further tightly fitted around the outer periphery of the plate refractory 6. The cooling gas passage 14 may be provided in the center of the fastening fitting 8, as shown in FIG. 2b, or may be provided on the lower surface of the plate refractory 6. Further, even if the hoop 10 does not have a relatively high temperature rise, it may expand and loosen depending on the operating conditions, so a hoop 10 having a structure in which the hoop is similarly cooled by cooling gas may be used in combination.

The plate refractories of the present invention were compared with plate refractories having a conventional structure that does not use fasteners, and the occurrence of cracks was compared.

Both the center member and the outer peripheral member are approximately the same shape,
Moreover, they were made of the same material. Figure 3 shows a conventional plate refractory structure in which zirconia insert bricks are cast with high alumina castable refractory, and Figure 4 shows a plate refractory structure of the present invention with a zirconia insert. The bricks are also equipped with fasteners.

A hoop is shrink-fitted to the outer periphery of both plate refractories.

The conditions for generating cracks were to heat the inside of the outlet using a burner (LPG + oxygen). The temperature was raised to 1500°C, maintained for 15 minutes, and allowed to cool.

As shown in Figures 5 and 6, in the plate brick of the conventional structure, cracks occurred in the central member and extended to the outer peripheral member, whereas in the plate brick of the present invention, cracks occurred in the central member. The crack ends at the end and does not extend to the outer peripheral member.
When wrapping fasteners around the outer circumference of the central member, the thickness of the plate refractories should be less than the width of the fasteners when two or three such plate refractories are used in combination. Since it is a device, this is to prevent the fastening metal fittings from protruding into the sliding surface.

Further, the holding mechanism for holding the castable refractory to the fastening fitting may be a simple one made by welding a V-shaped stud, for example, as shown in the drawings of the embodiment, but a mechanism having a similar holding force may be used. If so, it may have another structure.

On the other hand, in this invention, a case has been described in which zirconia is used for the central member and high alumina castable is used for the outer peripheral member, but of course other commonly used materials can be used.
Furthermore, instead of only two types of materials, three types of materials may be used to form a three-layer structure.

This invention also includes modifications that apply techniques used in other fields.

For example, as shown in FIG. 2, by wrapping the hoop 10 around the outer circumference of the plate refractory, even if the outer circumferential member cracks, it will not immediately become unusable.

In addition, when using materials with a large difference in thermal expansion between the central member and the outer peripheral member, as shown in Fig. 7,
Stress can be absorbed by inserting a sheet of inorganic fiber such as ceramic fiber 11 into the boundary.

Figure 8 shows a V-shaped stud 9 welded to the inner surface of a hoop 10 wrapped in castable refractory material.
The bond between the castable refractory and the hoop becomes even stronger.

In FIG. 9, stainless steel wire, wire mesh, etc. 12 are buried in advance when casting the castable in order to reinforce the castable refractory itself on the outer periphery.

As described above, in the present invention, since the center part is tightened with a fastening metal fitting, cracks that occur during operation can be confined to the center part as much as possible, and at least the occurrence of cracks penetrating the outer peripheral part can be suppressed.
Air can be prevented from being entrained in the molten metal flow. Furthermore, since the sliding surface can be easily handled during grinding work, the surface accuracy can be further improved. Furthermore, since a cooling mechanism consisting of a cooling gas passage provided in the fastening metal fittings is provided, the fastening metal parts are heated and expanded due to the temperature of the molten metal, reducing the fastening force and causing the central member of the plate refractory to touch the outer peripheral member. There is no problem such as protrusion or depression of the molten metal outlet, chipping of the edge of the molten metal outlet, uneven surface pressure, and bullion.

[Brief explanation of drawings]

Figures 1a and b are a schematic plan view and a cross-sectional view taken along the line A-A of a conventional insert type refractory, Figures 2a and b are schematic plan views of the plate refractory of the present invention, and Figure 3 is a conventional plate refractory. FIG. 4 is a schematic plan view showing the plate refractory of the present invention, FIG. 5 is a plan view of a conventional plate refractory, and FIG. 6 is a plan view of the plate refractory of the present invention. Figure 7, Figure 8, Figure 9
The figure is a schematic sectional view showing another embodiment of the present invention. 1... Material having high corrosion resistance, 2... Calcined refractory plate, 3... Mortar, 4... Molten metal outlet, 5... Center member, 6... Plate refractory, 7... Thickness, 8... Fastening metal fittings, 10... Hoop, 11... Ceramic fiber, 12... Stainless steel wire, wire mesh.

Claims (1)

[Scope of Claims] 1. In a plate refractory made of multiple materials including a central member in contact with molten metal and an outer peripheral member surrounding the outer periphery, the peripheral side of the central member has a width equal to or less than the thickness of the plate refractory. In addition, a fastening fitting having a cooling gas passage on the outer periphery is tightly fitted, and the outer peripheral member is made of castable refractory material integrally casting the central member together with the fastening fitting. Plate refractories for nozzles. 2. The plate refractory for a sliding nozzle according to claim 1, wherein the fastening fitting is provided with a mechanism for holding the castable refractory. 3. A plate refractory for a sliding nozzle according to claim 1 or 2, wherein the plate refractory is reinforced with a hoop. 4. The plate refractory for a sliding nozzle according to claim 3, which is equipped with a mechanism for holding the castable refractory on the inner surface of the hoop. 5. The sliding nozzle plate according to claim 1, 2, 3, or 4, characterized in that an inorganic fiber sheet is fitted between the central member and the outer peripheral member. Refractory. 6 Claims 1, 2, 3, 4, or 5, characterized in that a reinforcing metal member is embedded within the castable refractory outer peripheral member.
Plate refractories for sliding nozzles as described in .