JPH02435Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a lining structure for a reflux pipe of a vacuum degassing device.

(Purpose of the invention) In vacuum degassing equipment such as RH type and DH type,
The immersion tube that sucks and discharges molten steel into a vacuum chamber is
Significant wear and tear is caused by erosion from molten steel and slag. Therefore, when the remaining refractory lining becomes less, the immersion tube is removed from the flange and replaced with a newly prepared immersion tube.

However, the inner lining cracks due to thermal shock during use, and when the immersion tube is removed, the molten steel and slag that adhere to the inner surface of the inner lining, or the adhesive force of mortar interposed at the flange joint, cause cracks. There was a problem that the refractory material at the reflux pipe flange joint was stripped off.

FIG. 1 shows a state in which the refractory 4 of the flange joint of the reflux tube A is stripped off when the immersion tube B is removed in a conventional vacuum degassing apparatus.

Since the reflux tube is an integral part of the vacuum tank above it, it cannot be replaced like the immersion tube, and must be repaired every time it is stripped. Replacing the entire flange joint with refractories is uneconomical and less rapid. The method of filling only the stripped portion with monolithic refractory has a small repair effect because monolithic refractory has poor corrosion resistance.

(Structure and operation of the invention) The present invention aims to solve the above-mentioned conventional problems, and is characterized by having the refractory material sloped downward with respect to the inside direction in the lining of the flange joint. This is a reflux pipe for a vacuum degassing device in which the inner refractory is supported by frictional resistance due to the above-mentioned inclination.

To explain the present invention based on the drawings, in FIG. 2, which is a vertical cross-sectional view, and in FIG. will be established. A monolithic refractory material 3 such as mortar is filled between the lining 2 and the iron skin 1, and the lining 2 is fixed concentrically to the iron skin 1.

The refractory of the flange joint is divided with a downward slope relative to the inside direction. Inner refractory 2
is supported by the frictional resistance of this slope. The inclination angle is approximately 55 to 85 degrees, more preferably 60 to 83 degrees. Mortar will be placed on the slope if necessary.

The outer refractory 4b has a sloped back surface, and the support 5 protruding from the inner periphery of the steel shell 1 is supported by pressing it against the slope. The support of the outer refractory 4b is not limited to that shown in the drawings, but for example, an inverted L-shaped notch is formed at the lower end of the back surface, and a receiver protruding from the inner periphery of the steel shell is brought into contact with this notch. Alternatively, a receiver protruding from the inner periphery of the steel shell may be pushed into a U-shaped notch formed on the back surface. However, if a notch is formed, cracks are likely to occur starting at the notch due to concentration of thermal stress, so a support structure with the back surface sloped as shown in the figure is most preferable.

The material of the refractories 4a and 4b is not particularly limited, and for example, the main material is one or more selected from refractory raw materials such as refractory metal oxides, carbon, carbides, and nitrogen materials, and kneaded. It is a shaped refractory that is formed (by pressing, casting, stamping, etc.) and then fired if necessary.

The materials of the inner refractory 4a and the outer refractory 4b may be different. For example, one of them may be made of a high-grade material with better corrosion resistance.

By configuring the lining of the reflux pipe flange portion as described above, when the immersion pipe is removed, the occurrence of cracks that may cause the refractory material to be peeled off is reduced. This is thought to be because the temperature gradient of each refractory 4a, 4b during use is reduced by dividing the refractory and reducing its thickness. Further, a crack that occurs in one of the refractories is broken at the boundary of the slope and does not develop into a large crack.

When removing the immersion pipe, only the inside of the refractory is stripped off, as shown in Figure 1. In this invention,
Since the refractory is divided, only the inner refractory 4a damaged by stripping can be replaced. At this time, since the inner refractory 4a is supported by the inclined surface, it is only necessary to press the inner refractory 4a whose back surface is shaped to match the inclined surface.

Furthermore, in the conventional case, when attempting to replace the refractory of the flange joint, the support of the lining above it is lost, but in the present invention, the outer refractory 4b supports the upper lining, and the inner refractory 4a is replaced. It does not cause any trouble.

The inner lining is divided vertically in the circumferential direction, as in the past. Although the number of vertical divisions is not particularly limited, in this embodiment, as shown in FIG. 3, the number of divisions of the inner refractory 4a is larger than that of the outer refractory 4b.

In this way, the angle of the side surface of the inner refractory 4a with respect to the inner circumferential surface becomes smaller, making it easier to attach and detach the inner refractory 4a during repair. On the other hand, since the outer refractory 4b is large and the angle of the side surface with respect to the inner circumferential surface is large, there is no problem such as loosening of the stacking structure when removing the inner refractory 4a.
In order to obtain this effect, it is preferable that the number of vertically divided inner refractories 4a is 1.5 times or more, preferably 2 to 5 times as many as the outer refractories.

(Effects of the invention) As is clear from the above examples, the reflux pipe of the present invention is less likely to cause cracks in the refractory material at the flange joint, and can be quickly repaired when the refractory material is stripped off by removing the immersion pipe. It's easy to do. As a result, the operating rate of the vacuum degassing device can be significantly improved by reducing repair costs and repair time for the circulation pipe.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a conventional reflux tube with the inner lining of the reflux tube stripped off when the immersion tube is removed, and FIG. 2 is a vertical sectional view of the reflux tube according to an embodiment of the present invention. FIG. 3 is a sectional view taken along the line A-A in FIG. 1... Iron shell, 2... Lining, 3... Monolithic refractory, 4... Refractory of flange joint, 4a... Inner refractory of flange joint, 4b... Outer refractory of flange joint , 5... Receiver, A... Circulation pipe,
B...Immersion tube.

Claims (1)

[Claims for Utility Model Registration] 1. A vacuum degassing device in which the lining of a flange joint is divided with a refractory inclined downward toward the inside, and the inner refractory is supported by frictional resistance due to the inclination. Reflux tube. 2. The reflux pipe for a vacuum degassing device according to claim 1, wherein the number of vertically divided linings in the circumferential direction is larger for the inner refractory than for the outer refractory.