JPH0453614B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for forming a spout of a pot-type ladle that temporarily receives molten metal from a melting furnace.

(Prior art) In general, a dowel type ladle has a receiving part that receives molten metal, and a tap part that is separated from the receiving part by a control wall, the lower part of which communicates with the bottom of the receiving part, and the upper part that communicates with the pouring spout. It is equipped with

Conventional ladles for receiving molten cast iron are often bucket-shaped, which are circular when viewed from above and rectangular when viewed from the side, and the height H is slightly larger than the diameter D. In order to extract healthy cast iron with fewer inclusions from the bottom of the ladle when pouring into the mold, a dowel-type control wall is adopted at the tap hole, and the conventional control wall was a flat plate connected with refractory bricks. Many of them are shaped like this. However, in order to improve the removal rate of inclusions, it is necessary to design a tap that allows the molten metal at the bottom of the ladle to be tapped out in a short time with a small amount of movement. The side opening must be sufficiently narrowed and the cross-sectional area must be smoothly increased while curving upwards.Especially when using a spherical ladle with a small D/H, it is difficult to use a conventional flat control wall. The outlet shape described above cannot be obtained. The lining of the ladle must be replaced once every 1 to 5 days, so if the spout has a complicated shape, it takes time and effort to construct the lining and, in turn, change the shape of the tap.

(Objective of the Invention) An object of the present invention is to enable easy formation of a complex-shaped tap opening that can maintain a high removal rate of inclusions in the molten metal.

(Structure of the Invention) The present invention is a ladle that temporarily receives molten metal from a melting furnace, and has a receiving part for receiving the molten metal, which is separated from the receiving part by a control wall, and a lower part is connected to the bottom of the receiving part. In a dowel type ladle equipped with a tap spout whose upper part communicates with the pouring spout, a lining is applied to the inner surface of the outer shell of the ladle, and a portion of the lining corresponding to the tap spout is provided with an intervening part in the molten metal. It is made of foamed resin that can be burned out by heat and has the same shape as the tap hole, which is designed to maintain a high material removal rate, and has a shape that gradually increases in cross-sectional area while curving upward. A lining is placed over the core to form a control wall so that the upper part of the core remains exposed to the spout and the lower part to the bottom of the receiving part. This method is characterized in that the core exposed at the spout and the bottom of the molten metal receiving part is burned out after the process is completed.

(Example) FIG. 1 is a longitudinal cross-sectional view showing a pot-type ladle equipped with a spout formed according to the present invention. Reference numeral 1 denotes a spherical ladle outer shell made of iron plate, which integrally includes three supporting legs 4 and a spout wall 5. 2 is a lining body, and 3 is a lining control wall. The lining body 2 is stretched to a predetermined thickness on the inner surface of the outer shell 1, and is also integrally continuous with the upper portion 2a of the spout wall 5. 6 is an MG alloy pocket, and 20 is a receiving part for receiving molten cast iron.

The control wall 3 separates the hot water receiving part 20 and the hot water outlet part 7,
It is continuously formed integrally with the lining main body 2 so as to surround the tap opening part 7. The tap opening 7 is formed using a core 8 made of foamed resin, such as foamed polystyrene, which can be burned out by heat. The hot water outlet part 7 is connected to the hot water receiving part 20 through the narrowed opening 7a at the lower end.
The upper end communicates with the spout 10. Note that FIGS. 2 and 3 are cross-sectional views at - and - in FIG. 1, FIG. 4 is a partial plan view taken in the direction of arrows in FIG. 1, and FIG.

Next, the method for forming a tap hole according to the present invention will be explained in order of steps.

First, the tap opening 7, which corresponds to the tap opening, is designed to have a shape that can maintain a high removal rate of inclusions in the molten metal. Specifically, it is designed to have a shape in which the cross-sectional area gradually increases while curving upward, that is, from near the bottom of the receiving portion 20 toward the spout 10 . Next, a wooden mold having a concave portion having the same shape as the above-mentioned shape of the tap hole 7 is made, and the wooden mold is used to form the tap hole forming core 8 made of expanded polystyrene. Next (or before then) the lining body 2 is attached to the inner surface of the spherical outer shell 1 and is integrally continuous with the upper part 2a of the spout wall 5. This lining is formed by compacting a monolithic refractory material (star liner, etc.) with an air hammer, wooden hammer, etc. Then, the core 8 is brought into contact with a portion of the lining body 2 corresponding to the spout 7, and a lining of the same type as the lining body 2 is placed such that the upper end of the core 8 is placed in the pouring spout 10 and the lower end is in the receiving part 20. The control wall 3 is formed by pasting it on the core 8 in the same manner as the lining body 2 so that it remains exposed at the bottom of the core 8. As a result, the core 8 is sandwiched between the lining body 2 and the control wall 3. Next, the lining is dried by air drying or a burner drying method, and then the core 8 is preheated to high heat (about 1100° C.) with a burner to burn out the core 8. As a result, after the core 8 is burnt out, the tap hole 7 is formed.

(Effects of the Invention) As described above, according to the present invention, the tap hole 7 on the lining body 2 attached to the inner surface of the ladle outer shell 1
The part corresponding to the molten metal is machined into a shape that has the same shape as the tapping port 7, which is designed to maintain a high removal rate of inclusions in the molten metal, and has a cross-sectional area that gradually increases while curving upward. A tap hole forming core 8 made of foamed polystyrene that is burnt out by the generated heat is brought into contact with the core 8 so that the upper end of the core 8 remains exposed to the spout 10 and the lower end remains exposed to the bottom of the receiving part 20. A lining is placed over the core 8 to form the control wall 3, and after drying, the core 8 exposed to the spout 10 and the bottom of the receiving part 20 is burnt out. The tapping port 7, which is a space that can be easily removed and communicates with the pouring spout 10 and the receiving portion 20, and has an optimal shape to maintain a high removal rate of inclusions in the molten metal. It can be formed. Furthermore, since the core 8 used to form the spout 7 can be mass-produced in a separate process using a wooden mold or the like, no skill is required for lining construction, and anyone can accurately form the spout 7 in a predetermined shape. This makes it possible to stabilize the quality of cast products. In addition, since the burnt-out removal work of the core 8 can be done in a short time, the lining construction time and the time for forming the tap hole 7 can be shortened, which not only reduces costs but also reduces the number of spare ladles. can. In addition, the shape of the tap opening 7 can be easily changed according to the size of the ladle, the type of molten metal handled, etc., so it is possible to use a ladle with the optimal shape according to the work, and always maintain the best shape. Inclusion removal rate can be obtained.

Note that the present invention is equally applicable to conventional bucket-type ladles other than spherical. However, when applied to the illustrated spherical ladle, the drop in hot water temperature during tapping can be kept to a minimum, and the quality of the cast product can be improved.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a pot-type ladle equipped with a tap hole formed according to the present invention, FIGS. 2 and 3 are - and - sectional views of FIG. 1, and FIG.
A partial plan view in the direction of the arrows in the figure, Figure 5 is - of Figure 1.
FIG. 1... Ladle outer shell, 2... Lining body, 3...
...Control wall, 7...Tap spout section, 8... Core for forming the spout section, 10...Spout, 20...Mold receiving section.

Claims (1)

[Scope of Claims] 1. A ladle that temporarily receives molten metal from a melting furnace, which is separated from the molten metal receiving part by a control wall and whose lower part communicates with the bottom of the molten metal receiving part. In a dowel type ladle equipped with a spout portion whose upper part communicates with a spout, a lining is placed on the inner surface of the outer shell of the ladle,
The part on the lining corresponding to the tap opening has the same shape as the tap opening, which is designed to maintain a high removal rate of inclusions in the molten metal, and the cross-sectional area gradually increases while curving upward. A core made of foamed resin that can be burnt out by heat and formed into a rounded shape is brought into contact with the mold so that the upper part of the core remains exposed to the spout and the lower part remains exposed to the bottom of the receiving part. A dowel-type installation characterized in that a lining is stretched over the core to form a control wall, and after drying, the core exposed to the spout and the bottom of the molten metal receiving part is burned out. How to form the spout of a pot. 2. A method for forming a spout of a dowel type ladle according to claim 1, wherein the outer shell of the ladle is spherical. 3. A method for forming a tap hole of a dowel-type ladle according to claim 1, wherein the core for forming the tap hole is burnt out using a burner. 4. A method for forming a tap opening of a dowel type ladle according to claim 1, wherein expanded polystyrene is used as a core for forming the tap opening.