JPH0514144U - Porous refractory with steel case for molten steel container - Google Patents

Abstract

(57) [Summary] (Modified) [Constitution] In a porous nozzle 1 for molten steel container or a porous plug in which a porous nozzle brick 1 is fitted into a steel case 3 via a seal mortar 2, the steel case 3 is used. The roughening means comprises roughening the outer periphery of the surface, and the roughening means includes roughening by machining, roughening by applying or adhering refractory particles or attaching a refractory mortar sheet or ceramic sheet. By attachment. [Effect] There is no gas leak, nozzle clogging is reduced, and
It is now possible to use more than 0 charges.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a porous refractory with an iron skin case for a molten steel container, and more particularly to a porous refractory with an iron skin case having improved workability when the porous refractory with an iron case is attached to the molten steel container. In the present invention, the porous refractory material with a steel case for a molten steel container means a porous nozzle and a porous plug.

[0002]

[Prior Art]

 For ladle, tundish, etc. that receive molten steel, in order to prevent molten steel agitation during molten steel processing in the ladle, or to prevent nozzle clogging during molten steel injection, seal mortar with a porous nozzle brick at the bottom bottom of the container. A so-called porous nozzle or porous plug (hereinafter, simply referred to as a porous nozzle), which is fitted in a steel case via a nozzle, is embedded, and an inert gas such as Ar or N is blown into the molten steel through the nozzle. Is being done.

[0003]

[Problems to be solved by the device]

 For example, as shown in the partial vertical cross-sectional view of FIG. 4, when mounting the porous nozzle 1, the outer periphery of the porous nozzle, in other words, the outer periphery of the iron case 3 is coated with mortar, and then fitted into the holes of the mass brick 6. However, since the surface of the steel case is smooth, the mortar will come off, and the mortar will not be sufficiently filled between the mass brick and the steel case, creating a gap 7 between the mass brick and the steel case. Heat transfer from the iron case 3 to the mortar 2 and the bricks 6 is not sufficiently performed, and the iron case 3 is preferentially heated, and the iron case deforms and expands 8. The skin case and the seal mortar 2 are separated from each other to form a gap between the skin case and the porous nozzle brick, and the gas blown in is leaked by using about 5 charges.

For example, when a gas leak occurs in the above-mentioned porous nozzle, gas outflow from the inner surface of the nozzle hole in the porous nozzle cannot be expected, and nozzle clogging due to adhesion of alumina to the inner surface of the nozzle hole occurs, and the casting operation must be stopped midway. It causes problems such as not getting.

[0005]

[Means for Solving the Problems]

 As a result of various studies and experiments, the inventors of the present invention have developed the porous nozzle for molten steel container of the present invention as a result of various examinations and experiments in order to solve the above-mentioned defects of the conventional method. In a porous nozzle for a molten steel container in which a nozzle brick is fitted into a steel case through a seal mortar, it consists of roughening the outer surface of the steel case. It includes roughening, roughening by coating or adhering refractory particles, or refractory mortar sheet, and roughening by sticking ceramic sheet.

By adopting the technical configuration of the present invention, there is no gas leak phenomenon, nozzle clogging is drastically reduced, and it is possible to use more than 10 charges.

As the roughening of the surface of the iron case in the present invention, the iron case is roughened by mechanical processing such as shot blasting or knurling.

Further, there is roughening by coating or adhering refractory particles on the peripheral surface of the iron case, and FIG. 1 shows the refractory particles 2 on the peripheral surface of the iron case 3 coated on the peripheral surface of the porous nozzle 1. FIG. 4 is a vertical cross-sectional view showing an applied example, 4 is a gas pool provided on the outer periphery of the lower part of the porous brick, and 5 is an introduction pipe communicating with the gas pool 4.

FIG. 3 is a longitudinal sectional view showing an example in which the refractory particles 2 are applied to the porous plug in the same manner as in FIG. 1, and the same reference numerals as those in FIG. 1 indicate the same members (as the porous plug).

In the above two examples, the outer peripheral surface of the iron case 3 may be roughened.

The refractory particles described above may be commonly used refractory particles such as alumina, zircon, silica sand, etc. The particle size may be any particle size suitable for spraying or brushing, and generally 14 to 48 mesh. is there. For construction, knead the refractory particles with a commercially available heat-resistant paint or heat-resistant adhesive, and coat the circumference of the iron case with a thickness of 0.5 to 1.0 mm by spraying with a normal air gun or brush painting. .

As a specific example, 14 to 28 mesh alumina particles and a commercially available silver paint were kneaded and applied with an air gun to a thickness of about 0.8 mm.

Further, a fireproof mortar sheet or a ceramic sheet may be attached to the peripheral surface of the iron case to roughen the surface, and FIG. 2 shows the peripheral surface of the case 3 covered with the porous nozzle 1. It is a longitudinal cross-sectional view showing an example in which a refractory mortar sheet or a ceramic sheet 2'is attached, and reference numerals 4 and 5 are the same as those in FIG.

Examples of the composition of the refractory mortar sheet include a high-alumina molded mortar composed of 75 to 88% of Al ₂ O _{3 and} 9 to 14% of SiO ₂ , or a carbon addition level obtained by adding about 8% of C to these compositions. A flexible plate-like body before drying is suitable for any of the alumina-based molded mortars.

Further, as an example of the ceramic sheet, a flexible and cushioning plate-like body made of a mixed composition of SiC, Al ₂ O ₃ , SiO ₂ , MgO, ZrO ₂ and C is suitable.

The plate-shaped body may be attached to the peripheral surface of the iron case by using a commercially available adhesive, for example, an instant adhesive, a woodworking bond, an acrylic bond, a vinyl bond or the like.

[0017]

【Example】

 As shown in FIG. 1, a porous nozzle of the present invention was prepared by coating a steel case with a thickness of 0.5 mm, a mixture of alumina particles mixed with a heat resistant adhesive as a refractory, and drying it.

Conventional porous nozzles that were not subjected to such a treatment were prepared, and mortar was applied to the outer peripheral surface of each of these two types of porous nozzles and mounted on a mass brick. The results of measuring the pressure in the gas pool during the operation of these two types of porous nozzles are plotted in FIG. As can be understood from this graph, for example, if the normal range of the back pressure is 0.8 to 1.0 kg / cm ^{2 under} such a use condition, the conventional type will have a gas leak of about 5 charges. However, it was found that the device of the present invention has sufficient pressure resistance and exhibits the intended effect of the present invention.

[0019]

[Effect of the device]

 (1) The filling property of mortar at the time of construction is perfect, the coated iron case is not deformed, and the gas leak phenomenon is eliminated.

(2) Nozzle blockage is drastically reduced, and casting can be performed smoothly.

(3) In the conventional method, it was generally necessary to replace the porous brick with about 5 charges, but the use of the present invention made it possible to continuously use 10 charges or more.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an example in which refractory particles are applied to the peripheral surface of a steel case-covered porous nozzle.

FIG. 2 is a vertical cross-sectional view of an example in which a refractory mortar sheet or a ceramic sheet is attached to the peripheral surface of a steel case-covered porous nozzle.

FIG. 3 is a vertical sectional view similar to FIG. 1 in which the present invention is applied to a porous plug.

FIG. 4 is a partial vertical sectional view showing an example of a defect of a conventional product.

FIG. 5 is a comparison graph plotting pressure measurements in a gas pool of the present invention product and a conventional product.

[Explanation of symbols]

 1 Porous nozzle or porous brick 2 Refractory particles 2'Refractory mortar sheet or ceramic sheet 3 Steel case 4 Gas pool 5 Gas inlet pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyasu Hatsuji 603-1 Higashikatakami, Bizen City, Okayama Prefecture (72-6) Inventor Shunji Takebayashi 8-1-2, Kamiryodai, Tarumi-ku, Kobe City, Hyogo Prefecture (72) Inventor, Yasuaki Mikata 1-493 Nishijiyugaoka, Shizome-cho, Miki-shi, Hyogo Prefecture (72) Inventor Norio Hasegawa 4-2-1, Edayoshi, Nishi-ku, Kobe-shi, Hyogo

Claims (4)

[Scope of utility model registration request] 1. A porous refractory with an iron skin case for a molten steel container, wherein a porous brick is fitted into the iron skin case via a seal mortar, wherein the outer circumference of the iron skin case is roughened. Porous refractory with steel case for molten steel container. 2. The porous refractory with a steel case for a molten steel container according to claim 1, wherein the surface of the iron case is roughened. 3. A porous refractory with a steel case for a molten steel container, characterized in that refractory particles are applied or adhered to the surface of the iron case, the porous refractory with a steel case for a molten steel container. 4. A porous refractory with a steel case for a molten steel container, wherein a refractory mortar sheet is provided on the surface of the steel case,
Porous refractory with a steel case for a molten steel container, which has a ceramic sheet attached.