JPH024776Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention provides a slide valve device for controlling the flow rate of molten steel in a ladle for casting molten steel, for example.
This invention relates to improvements in refractory insert rings disposed in molten steel flow holes of refractories constituting slide valves such as insert nozzles, bottom plates, slide plates, and shoot nozzles.

Prior Art In a slide valve device, when the slide valve is closed to temporarily interrupt the flow of molten steel, etc., molten steel condenses in the molten steel flow hole in the bottom plate above the sliding surface of the slide plate. However, there was a problem in which the slide plate became obstructed and the operation of the slide plate was hindered when the water flowed out again.

Conventionally, as a means for preventing the solidification of molten steel when the slide valve is closed, a gas permeable body made of a refractory material is provided in the molten steel passage hole of the bottom plate of the slide valve, as disclosed in Japanese Patent Publication No. 49-21016, for example. A vessel with a sliding closure for liquid melts, characterized in that an inert gas, such as argon or nitrogen, is supplied to the melt (such as molten steel) through the valve, in particular when the slide valve is in the closed position. There is an invention.

In addition, it prevents condensation of molten steel etc. when the slide valve is closed, prevents clogging of the lower nozzle hole due to Al precipitation, etc., and protects the hole wall surface from wear and tear due to the formation of a gas film between the molten steel and the molten steel distribution hole wall. As disclosed in Japanese Utility Model Application Publication No. 59-32454, a permeable brick made of porous refractory material is fixed around the outflow hole of a fixed plate in a sliding nozzle device, and a fixed plate is attached to the gas permeable brick. There is a proposed mechanism for preventing molten steel from condensing in a sliding nozzle device in which a through hole is bored toward the lower end surface of the opening.

Problems to be solved by the invention However, in the former case, the main purpose is to prevent molten steel, etc. from condensing when the slide valve is closed; Sometimes, it is not effective enough to protect the walls of molten steel flow holes and prevent melting and damage of refractories.

Also, the latter, judging from the drilling state of the through hole,
Although it has the effect of promoting the effect of preventing molten steel from condensing when the slide valve is closed, it does not have a sufficient effect to prevent the lower nozzle hole from clogging when molten steel or the like flows out or prevent damage to the hole wall surface. The reality is that the technology that can achieve this has not yet been developed.

Means for Solving the Problems The present invention was made by focusing on such conventional problems, and it is possible to prevent molten steel from condensing when the slide valve device is closed, as well as prevent molten steel from flowing out. The purpose is to solve the problems of conventional technology by adopting an inert gas (hereinafter simply referred to as "gas") ejection gap that can sufficiently form a gas protective film between the molten steel and the wall surface of the flow hole. shall be.

Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

FIG. 2 is a cross-sectional view showing the conventional structure of a slide valve attached to the bottom of a ladle, in which 5 is a ladle shell, 6 is a ladle lining refractory, 7 is a nozzle receiving brick, 8 1 is an insert nozzle, 9 is a bottom plate, 10 is a slide plate, 11 is a shoot nozzle, 12 is a housing, 13 is a bottom plate support hardware, 14 is a slide case, 15 is a skirt, 16 is a shoot nozzle case, 17 is a hydraulic cylinder guide Pieces 18 and 18 respectively show brick fixing fittings, and show an example in which the insert ring 1 of the present invention is disposed in the molten steel flow hole portion of the bottom plate 9. The insert ring 1 is not limited to the illustrated bottom plate, but can be inserted into the molten steel flow hole of the insert nozzle, slide plate, or refractory of the slide valve of the shoot nozzle.

FIG. 1 shows an example of an insert ring for a slide valve according to the present invention, FIG. 1a is a plan view, and FIG. 1b is a cross-sectional view taken along the line -1. The insert ring refractory may be either a porous gas-permeable refractory or a dense refractory.

In FIG. 1, an insert ring 1 has a molten steel flow hole 2 therein, and 3 is a wall surface of the flow hole.
A gas ejection gap 4 opening from the outer peripheral surface of the insert ring 1 to the wall surface 3 of the flow hole is formed extending vertically inside the ring wall at a constant angle θ.

The opening angle θ of the gas ejection gap 4 is
It is necessary to set it at 85 degrees or less with respect to the tangent to the circumference. This setting angle makes the flow of molten steel more efficient when the slide valve is closed by the gas jetted into the molten steel distribution hole 2 via the gas jetting gap 4, and also causes a swirling flow between the molten steel and the distribution hole wall surface 3. , is important for making gas film formation more effective.

In other words, in order to obtain a swirling flow of ejected gas,
As for the ejection angle, the effect will be poor unless the center of the insert ring is made eccentric as much as possible, and for this purpose, it is sufficient to deviate from 90° to the circumferential tangent, but if it exceeds 85°, the rotation Although it requires a large amount of energy, it is difficult to provide directionality for rotation, and the area in which the protective film is formed by the gas is also narrow, so there is a risk that the wall surface of the flow hole cannot be expected to be sufficiently protected. Therefore, it is necessary to keep it below 85°.

The size of the cross section of the gas ejection gap 4 is necessary for the flow of molten steel in the molten steel flow hole of the bottom plate in order to prevent the molten steel from condensing when the slide valve is closed, and also to prevent the formation of a gas film when the molten steel flows out. From the viewpoint of the speed and amount that can supply the necessary ejected gas, it is sufficient to have a size that matches the capacity of the molten steel ladle, etc. If the gap is too large, the ejected gas will cool the molten steel, which will have an adverse effect. At the same time, the peripheral equipment for supplying gas also needs to be large, which is uneconomical, so it is desirable to have it as small as possible (for example, 2 mm or less). can achieve the purpose.

If the ejection angle of the gas ejection gap can be set as described above, the cross-sectional shape can be any shape such as a circular arc or a shape narrowed on the molten steel flow hole side. That is, the gap 4 may be formed in a part of the height of the ring wall or over the entire height, and some examples thereof are illustrated in plan and side views in FIGS. 3 to 6 a and b. It has been done. Further, the cross-sectional shape of the gap 4 is not limited to a straight line, but various curved shapes, bent shapes, and combinations thereof, as shown in FIG. 7, can produce similar functions and effects.

The insert ring 1 of the present invention is fixed, for example, to the molten steel flow hole of the bottom plate 9 with a filler layer such as refractory mortar, flexible fireproof board, etc. interposed therebetween.

The insert ring of the present invention can be applied to a rotary type slide valve or a combination of a rotary type and a linear type slide valve, and can also be widely applied to a three-layer type slide valve.

Effects of the Invention Since the present invention has the configuration as described in detail above, the gas ejected from one or more gas ejection gaps 4 in the direction of the molten steel flow hole 2 is directed to the wall surface of the flow hole 2.
This generates a circumferential motion along the flow and forms a gas film that covers a wide range of the flow hole wall surface 3. Therefore, when the slide valve is closed, the molten steel accumulated near the bottom plate is covered with a circular flow. It not only has the effect of promoting the flow of molten steel and efficiently preventing condensation by causing movement, but also has the effect of opening the slide valve and covering the wall surface of the flow hole from molten steel when molten steel flows out. This not only extends the life of the refractory, but also effectively eliminates problems such as aluminum clogging of the refractory below the chute nozzle.

[Brief explanation of the drawing]

Fig. 1 a and b are a plan view and side view showing an embodiment of the insert ring of the present invention, Fig. 2 is a sectional view of a slide valve to which the insert ring of the present invention is applied, and Figs. 3 to 6 a, b are a plan view and a side view showing several examples of other shapes of the gap 4 in the present invention,
FIG. 7 is a plan view showing an example in which the gap 4 is curved or bent, and in the figure: 1 is an insert ring, 2
is a molten steel distribution hole, 3 is a wall surface of the distribution hole, 4 is a gas ejection gap, 5 is a ladle shell, 6 is a ladle lining refractory, 7 is a nozzle receiving brick, 8 is an insert nozzle, 9 is a bottom plate, 10 is a slide plate, 11 is a shoot nozzle, 12 is a housing,
13 is bottom plate support hardware, 14 is a slide case, 15 is a skirt, 16 is a shoot nozzle case, 17 is a hydraulic cylinder guide piece, 1
8 is a brick fixture.

Claims (1)

[Scope of utility model registration request] In a refractory molded body that is inserted and fixed into a molten steel distribution hole of a refractory that constitutes a slide valve device such as an insert nozzle, bottom plate, or shoot nozzle, the vertical axis has an angle θ of 85° or less with respect to the tangent to the molten steel distribution hole wall circumference. An insert ring for a slide valve, characterized in that one or several gas ejection gaps 4 extending in the direction are opened on the inner periphery of the wall surface of the flow hole.