JPH0343221Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a porous plug for blowing gas used for stirring molten metal.

Conventional Technology A porous plug is attached to a molten metal container such as a ladle or tundish, and blowing is performed by blowing gas into the molten metal, but as the inner wall of the molten metal container wears down, the porous plug also melts and wears away. Misjudging the amount of wear and tear can lead to serious problems such as hot water leaks. Therefore, the usage limits of porous plugs must be clearly determined. However, in actual use, the amount of melting loss of a porous plug is checked with the naked eye from a long distance under adverse conditions such as red-hot conditions, so it is quite difficult to judge accurately.

Therefore, it has been proposed to determine the shape of a porous plug by setting the cross-sectional area ratio to 1:2 or more in the middle part, or by providing a step with extremely dissimilar shapes, as in Japanese Utility Model Application Publication No. 57-122751. ing.

Problems to be Solved by the Invention However, even with the proposed porous plug, it is difficult to operate under adverse conditions when viewed from a long distance with the naked eye, and the erosion of the inner permeable refractory and the outer dense Because the melted surface of the refractory is smooth and continuous, it is difficult to judge the shape of the breathable refractory, and it may not be possible to accurately judge the residual heat of the porous plug due to the change in the shape of the top and bottom of the breathable refractory. .

Means for Solving the Problems The present invention was developed in view of the above points.It is a fire-resistant porous material that is attached to the bottom or side wall of a molten metal container such as a ladle and into which a specified gas is blown. Inside the plug, there is a rectangular, circular, pattern, etc. with a width of approximately 0.5 to 10 mm and a depth of approximately 5 to 50 mm, making it possible to detect the melting state of the porous plug when the molten metal container is empty. An object of the present invention is to provide a porous plug for blowing gas, which is characterized in that it has a space section and a gas pool section of a predetermined size is provided at the center of the cross section provided with the space section.

Example The present invention will be explained below based on examples.

1 to 4 show an embodiment of the present invention.
As shown in Fig. 1, the porous plug 1 is formed into a slightly elongated truncated cone shape with a gas outlet tapering at the tip side, and has a gas supply pipe 2 for gas supply protruding from the rear end. . Then, on the inside of the center of the porous plug 1, a breathable refractory material 3 that allows gas to pass through, similar to the conventional one, is placed at approximately two-thirds of the tip side as shown in Figures 1 and 2. is formed into a conical part 4 with a circular cross section along the outer shape, and the rear side of the lower one-third thereof is formed into a rectangular cross section along the outer shape as shown in Figures 1 and 3. It is integrally formed in the quadrangular pyramid-shaped part 5. Said square pyramidal part 5
As shown in FIGS. 1 and 3, a square annular groove-shaped space 6 is provided along the outer periphery of the quadrangular pyramidal section 5 on the upper circumference, and the lower side of the breathable refractory 3 is The shape of the quadrangular pyramidal portion 5 can be easily distinguished. Also,
A disk-shaped gas pool portion 10 of a predetermined size is provided at the center of the conical portion 4 having a space 6 around the periphery.
has been established. The space part 6 and the gas pool part 10 are
When manufacturing the porous plug 1, the porous plug 1 can be easily formed by attaching a combustible material such as cardboard or expanded polystyrene to the breathable refractory 3 and burning it out. It is most preferable that the space 6 has a width of about 0.5 to 10 mm and a depth of about 5 to 50 mm, but it can be modified to some extent depending on the environment. On the outside of the breathable refractory 3 formed in this way, a first
As shown in Figures 3 to 3, it is covered with a dense refractory 7, and furthermore, an iron skin 8 made of an iron plate is provided around the outer peripheral surface.

As a result of, for example, attaching the porous plug 1 to the bottom of the molten metal container 9, blowing inert gas such as argon gas to blow the molten metal, and using it a required number of times, the fourth As shown in the figure, the upper conical part 4 of the porous plug 1 was melted and the lower quadrangular pyramidal part 5 was exposed. At this time, a rectangular ring-shaped space 6 appears as shown in Figure 4, and when the empty container is still red-hot, the depressed part of the space 6 appears as a black frame like a shadow when observed with the naked eye. It was clearly determined that the loss had reached the square pyramidal part 5 at the bottom of the breathable refractory 3.

Therefore, the usage limit can be visually confirmed without misjudging the amount of corrosion damage of the porous plug, and the timing of replacing the porous plug or repairing the molten metal container or the like can be accurately determined.

In addition, a little before the rectangular annular space 6 appears, the space of the gas pool part 10 appears in the center, so the gas pool part 10 also clearly shows a black disk shape in the center and can be distinguished. can do. The gas pool section 10 stores inert gas at a uniform pressure until it is eroded.
This is preferable because the inert gas can be blown into the upper part of the porous plug 1 side so that it can be blown out uniformly from the tip end face of the plug.

Other Embodiments FIG. 5 shows another embodiment of the porous plug 1 of the present invention. In this embodiment, the inner breathable refractory 3 is formed by dividing into upper and lower halves, and as in the previous embodiment, a space 6 is provided around the lower quadrangular pyramidal part 5, and the upper conical part 5 is provided with a space 6. A gas pool portion 10 is provided by recessing the lower surface of the shaped portion 4 by approximately several mm.

In this embodiment as well, the usage limit of the porous plug can be clearly determined as in the above case, and since a gas pool is provided, inert gas etc. can be uniformly blown out from the plug tip surface.

In the above embodiments, the breathable refractories were formed with the upper and lower cross-sectional shapes having easily distinguishable circular and rectangular shapes, but they may be combined with other easily distinguishable shapes such as polygonal shapes. This can also be done as appropriate.

Still Other Embodiments As still other embodiments of the present invention, FIG.
As shown in FIG. 7, without changing the cross-sectional shape of the breathable refractory 3, a rectangular ring-shaped space 6 with cutout corners parallel to each other is provided in the middle of the porous plug 1. Can be formed. Also, the 8th
As shown in Figures to Figure 11, a circular or notched circular space 6 is provided, and a space 6 is formed with rectangular and circular small grooves spaced at regular intervals in a circular pattern pattern. It is also possible. In addition, as shown in FIGS. 12 to 14, a pair of parallel space portions 6 or the patterned portions as described above are arranged at predetermined intervals in multiple stages, such as two upper and lower stages, to create a porous structure. It is also possible to easily manage the amount of erosion of the plug 1 quantitatively over multiple stages.

In this way, the groove-like space can be made into an easily recognizable parallel shape, annular shape, pattern, etc., without particularly changing the cross-sectional shape of the breathable refractory.

In the above embodiment, a plug without a through hole is shown, but the present invention can be similarly applied to a plug with a through hole.

Effects of the invention As described above, in the present invention, when a predetermined amount of the porous plug is eroded, even if the molten metal container is in a bad red-hot environment, The gas pool part clearly appears in the black annular, circular, or rectangular shape,
It can be clearly identified with the naked eye and the state of melt damage can be confirmed, making it possible to accurately judge whether to replace the porous plug or repair the inner wall of the molten metal container, thereby reliably preventing the occurrence of major accidents. By means of the gas pool part that can determine the usage limit of the porous plug described above, the inert gas such as argon gas supplied from the bottom of the porous plug becomes a uniform pressure, and the porous plug above the gas pool part has a uniform pressure. This allows the inert gas to be blown out uniformly from the tip of the plug.

[Brief explanation of the drawing]

Figure 1 is a side sectional view of one embodiment of the present invention;
Fig. 3 is a cross-sectional view taken along arrows A-A and B-B of the same as above, Fig. 4 is a side sectional view for explaining the melting state of the above, and Fig. 5 is a side sectional view of another embodiment of the same as above. Figures 6 and 7 are side sectional views and cross-sectional views taken along the line C--C of still other embodiments of the same as above, and Figures 8 to 11 are cross-sectional views of still other embodiments of the same as above, respectively. 12 to 14 are a side sectional view and a cross sectional view taken along arrows D-D and E-E of still another embodiment of the same. 1...porous plug, 3...breathable refractory,
4... Cone-shaped part, 5... Square pyramid-shaped part, 6... Space part, 7... Dense refractory.

Claims (1)

[Scope of utility model registration request] Inside a fire-resistant porous plug that is attached to the bottom or side wall of a molten metal container such as a ladle and injects a specified gas, it is possible to detect the state of melting of the porous plug when the molten metal container is empty. An easily recognizable rectangular, circular, patterned, etc. space with a width of approximately 0.5 to 10 mm and a depth of approximately 5 to 50 mm is provided, and a predetermined size is provided in the center of the cross section in which the space is provided. A porous plug for gas blowing characterized by having a gas pool portion.