JPS61259867A - Method for lining vessel for molten metal by castable refractories for pouring - Google Patents

Abstract

PURPOSE:To form a foamless uniform lining on the inside wall of a metallic vessel and to increase the lifetime thereof by pouring castable refractories which are deaerated by oscillation in a hopper through an inflow pipe into the spacing between said vessel and molding flask disposed therein from the bottom. CONSTITUTION:The molding flask 3 is disposed in the vessel 1 for molten metal. The hopper 5 is oscillated to remove the foam contained in the castable refractories existing in the hopper. The deaerated pouring material 4 is poured through a pouring pipe 8 into the space 7 between the vessel 1 and the flask 3 from the bottom. The material 4 fills the space 7 in the foamless state and forms the lining material having the increased lifetime.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for lining a molten metal container using a castable monolithic refractory. The present invention relates to a method for lining a molten metal container using castable monolithic refractories.

(Prior Art) Conventional lining methods for molten metal containers include a slinger method using a slinger machine and a stamp method using a stamp rammer. According to the authors, in recent years, the pouring construction method, in which monolithic refractories are poured, has been used because it is efficient and powerful since it requires large-scale mechanical equipment. According to the example of the pouring construction method using the above-mentioned monolithic refractories, approximately 5 to 14% water is added to provide the necessary fluidity during construction.
Usually, the clay is mixed into a slurry and then filled between a container for molten earthwork metal and a formwork. In this construction method, a formwork, or core rod, is positioned and placed in a ladle, and the kneaded monolithic refractory is poured between the formwork and the regular bricks, or permanent lining, in the ladle. . At this time, during pouring, the monolithic refractories are filled while being directly vibrated by a vibration imparting means such as a rod-shaped vibrator, or the monolithic refractories are filled while being indirectly vibrated through the formwork. It is. The reason why vibration is applied during pouring work is primarily to remove air bubbles present in the kneaded monolithic refractory.

However, according to the above method, air bubbles still remain in the cast monolithic refractory as described later, so a method of pouring under reduced pressure to eliminate the remaining air bubbles has been proposed, for example in Japanese Patent Application Laid-Open No. 53 This method is disclosed in Japanese Patent No. -99218. According to the invention described in the publication, the entire process from the cross-contact of the monolithic refractory to the pouring is performed under reduced pressure, so that air is no longer entangled in the poured refractory.

In addition to the method disclosed in the above publication, JP-A-55-92
According to the invention described in Publication No. 880, after the monolithic refractory is poured into the space between the double cylindrical inner frame and the ladle permanent lining, the refractory in the space is subjected to a depressurization treatment while applying vibrations. By doing this, air bubbles contained in the refractory are degassed.

Further, Japanese Patent Application Laid-Open No. 119328/1983 discloses a method of applying vibration to flow materials into a fluid state from a cylinder mouth and laminating them while applying vibration.
Furthermore, according to Japanese Patent Application Laid-open No. 53-75205, a material that solidifies immediately when vibration is cut off is prepared, for example, by a material equipped with an outflow chute and a vibrator, the tip of which is suspended so that it can be raised and lowered parallel to the central axis of the ladle. An apparatus is disclosed for applying a lining by flowing the flow from a supply tank to a portion of a ladle to be lined.

(Problems to be Solved by the Invention) By the way, according to the conventional pouring method, a large amount of air is drawn in when monolithic refractories are mixed and installed, and air bubbles remain in the refractory lining layer. It had the disadvantage that the porosity was extremely high, the erosion by slag etc. was large, and the durability was low. In addition, the construction method using a rod-shaped vibrator relies on manual labor, which has the disadvantage that the filling density of the poured refractory is uneven, making it difficult to save labor.

In addition, according to the method of vibrating the frame, the vibrations in the poured material are attenuated as the distance from the vibration source increases, and the vibrations are not uniformly distributed throughout the material, but also the frame metal body vibrates. Not only is it necessary to vibrate the material that has already begun to harden, but since the construction is carried out in the atmosphere, sufficient degassing is not possible, and in terms of equipment, many motors are required. There are also some drawbacks.

According to the above-mentioned Japanese Patent Application Laid-Open No. 53-99218, a device for controlling pressure reduction such as a vacuum pump is required, which has the disadvantage that the equipment becomes expensive. Also, the above-mentioned Japanese Patent Application Laid-Open No. 55-928
According to No. 80, the invention described in JP-A No. 53-99218 is also cheaper in terms of equipment, but only the part of the poured material that is close to the inner frame is degassed. The disadvantage is that it is not possible. Also, the above-mentioned Unexamined Patent Publication No. 51-11
According to Publication No. 9328, there is a restriction that a material must be selected that flows out from the tip of the lower trough and solidifies as soon as it is released from vibration, but it is also applicable to material storage and supply equipment in general. Since high vibrations must be applied, equipment costs for the device are high, and there are problems in terms of durability and maintainability of the device.

(Means for Solving the Problems) An object of the present invention is to provide a method for constructing molten metal lining using castable monolithic refractories, which eliminates and improves the drawbacks and problems of the conventional methods and devices. The above object can be achieved by providing the method described in the claims. That is, the present invention provides a lining construction method in which a formwork is positioned and arranged in a molten metal container, and an amorphous refractory is poured into a space formed between the inner wall of the container and the formwork (in which a kneaded amorphous refractory is A large refractory material is continuously or intermittently charged into a thread tube having a discharge pipe, and after vibration is applied in the hopper to degas the air bubbles contained in the refractory material, the material is discharged into the space through the discharge pipe. A monolithic refractory for pouring characterized in that a degassed refractory is supplied into the space, and the lower end of the discharge pipe is immersed in the refractory charged into the space during the supply period. The present invention relates to a method for lining a molten metal container.

Next, the present invention will be explained in detail with reference to the drawings.

The core frame 3 is positioned and placed on the permanent tension brick built at the bottom of the molten metal container shell 1 of FIG. Next, a discharge pipe 6 vertically installed at the bottom of the hopper 5 containing the monolithic refractory material C (hereinafter referred to as pouring material) 4 is inserted into the space 7 formed between the shellwork and the core frame 3. Let it hang down. A vibration generator (not shown) is fixedly installed in the hopper 5, or a rod-shaped vibrator is distributed in the hopper 5 at a position where it is immersed in the pouring material 4.

First, to start construction, the lower end of the exhaust pipe 6 is suspended so as to be in contact with the surface of the permanent 7 lining brick 2 in the space 7, and then the material 4 is poured into the hopper 5 while operating a vibration generator or rod-shaped vibrator. After charging, the air bubbles contained in the pouring material 4 are vibrated and the inside of the pouring material 4 is raised to degas it. Furthermore, this degassing operation is different from the conventional degassing method in which a rod-shaped vibrator or vibration motor is used in the core frame, and is limited to degassing air bubbles in the pouring material 4 in the hopper 5. Therefore, it is easy to sufficiently remove the air bubbles inside the pouring material.At this time, the vibration intensity can be sufficiently degassed by applying an excitation force of 1 to 3G. The pouring material 4 deaerated in the hopper 5 is discharged from the hopper 5 through the discharge pipe 6 into the space 7, and during this discharge, the tip of the discharge pipe 6 is constantly immersed in the already discharged pouring material. Therefore, atmospheric entrainment is completely prevented.

That is, the pouring material discharged into the space 7 flows in the outer circumferential direction of the core frame 3 due to its fluidity, and the space 7 is gradually filled with the pouring material from the bottom, and the filling height gradually increases. During this time, the lower end of the discharge pipe 6 is immersed in the pouring material as described above; As the height increases, it is advantageous to adjust. In this way, keeping the lower end of the discharge pipe always immersed to some extent in the pouring material prevents atmospheric air from re-mixing into the degassed pouring material. According to the present invention, in order to promote the discharge of the pouring material from the discharge pipe 6, a vibrator may be provided in the middle of the discharge pipe 6, and also to prevent the atmosphere from coming into contact with the pouring material. The pouring material can also be pumped through the discharge pipe 6 using a pressure feeder equipped with a flexible telescoping section of a type capable of pumping the pouring material without having to do so. The pressure feeding machine described in New Patent Registration No. 1173562 can be used. In addition, for degassing inside the hopper 5, a shutter 9 is connected to the flexible tube 8 provided under the hopper 5 and controls opening and closing of the discharge passage, as shown in FIG. 2 (4), ω). Alternatively, a pressure feeder 10 is provided, and when pouring the material into the hopper 5 for the first time, the shutter 9 or the pressure feeder 10 is closed, and vibration is applied to the material to degas the material. Then, operate the shutter 9 or the pressure feeder 10 to start discharging the pouring material. After that, repeat this operation, or pour a new one with the previously supplied pouring material remaining in the hopper 5. Deaeration can be performed by adding material and applying vibration.

Next, the present invention will be explained by examples.

Example ・65-70% zircon as a pouring material.

A 5-fold diluted silica sol solution was mixed with a refractory consisting of 5i0225 to 30% and a hardening agent (cement) of 5% so that the amount was 5.5 to 5.7% of the weight of the refractory.

A 5 m long discharge pipe was installed at the bottom of the hopper, which can accommodate approximately 2 1 m of poured material, and a vibrator (rated 5 kW) with a built-in eccentric motor installed on the side wall of the hopper was used as a vibrator. .

First, a core frame was placed in a ladle, and the space between the core frame and the inner wall of the ladle was filled with pouring material via the hopper and discharge pipe according to the method of the present invention.

After that, the ladle was dried and hot metal was poured into it, and the number of times the ladle could be used was investigated.

As a result, we were able to achieve a service life of 95 times.

Furthermore, compared to the conventional lining construction method in which the core frame is vibrated and filled with pouring material, the ladle was lined with 80 cycles, and the present invention has extremely good results. It turns out that it is possible to cite the following.

By the way, the lifespan of a ladle lined with regular bricks is 9.
The service life of 95 times obtained by the present invention is comparable to that of 0 to 100 times.

(Effects of the Invention) As described above, according to the present invention, uniform lining relining without bubbles can be performed with less equipment cost and less labor than conventional methods, and as a result, lining relining can be performed with less air bubbles. The service life of the product will increase dramatically.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional explanatory diagram showing the arrangement relationship of the hopper, discharge pipe, and ladle when the construction method of the present invention is applied to the ladle, and Fig. 2 (4), ω) shows the arrangement of the hopper, the discharge pipe, and the ladle, respectively. FIG. 2 is a vertical cross-sectional explanatory view of a hopper including a shutter and a pressure feeder. 1... Molten metal container, 2... Permanent lining brick, 3
... core frame, 4 ... pouring material, 5 ... hopper, 6 ... discharge pipe, 7 ... space, 8 ... flexible tube. 9...shutter, 10...pressure feeding machine.

Claims (1)

[Claims] 1. In a lining construction method in which a formwork is positioned and placed in a molten metal container and a monolithic refractory is poured into the space formed between the inner wall of the container and the formwork, the kneaded monolithic refractory is poured into a discharge pipe. The refractory is charged continuously or intermittently into a hopper having a refractory, and after being vibrated in the hopper to degas the air bubbles contained in the refractory, the degassed refractory is introduced into the space via a discharge pipe. lining of a molten metal container using a monolithic refractory for pouring, characterized in that the lower end of the discharge pipe is immersed in the refractory already charged into the space during the supply period. Method.