JPS61262459A - Packing method for packing material to sliding nozzle - Google Patents

Abstract

PURPOSE:To smooth the discharge of a packing material and the outflow of a molten metal by heating the packing material and packing said material to the upper part of sliding nozzle in the case of packing the packing material consisting of granular refractories into the upper part of the sliding nozzle. CONSTITUTION:The packing material 11 is preliminarily heated to >=200 deg.C and is then packed into the nozzle part of a vessel 1 for molten metal in the stage of supplying said material to the nozzle part. The molten metal 4 transferred thereafter into the vessel 1 is therefore prevented from solidifying. Since the packing material is preheated, the thermal expansion of said material is small when the material is heated by the molten metal 4. the overpacking of the material 11 is thus obviated. The discharge of the material 11 and the outflow of the molten metal 4 are smoothly executed when the sliding nozzle is opened.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention is applicable to transfer of molten metal from a molten metal container such as a tundish or ladle for continuous casting to another container or mold, etc. This invention relates to a method for filling a sliding nozzle at the bottom of a molten metal container, which is applied to enable smooth flow of molten metal from the molten metal container.

(Prior art) To allow molten metal to flow out without tilting the molten metal container when transferring molten metal from a molten metal container such as a tundish or ladle for continuous casting to another container or mold. for.

A nozzle is often provided at the bottom of the molten metal container to control the outflow of the molten metal.

Conventionally, stopper head nozzle type nozzles have often been employed as the above-mentioned nozzles, but recently sliding nozzle type nozzles have come to be employed.

The attached drawing is a cross-sectional view of the sliding nozzle portion of a molten metal container that adopts the sliding nozzle method,
1 is a molten metal container, 2 is a refractory brick on the inner surface of the container, and 3 is an outer shell of the container. Molten metal 4 is accommodated inside the molten metal container 1.

Also, 5 is the nozzle part brick, 6 is the upper nozzle brick, 7 is the nozzle part brick,
is a fixed brick, 8 is a sliding brick, 9 is a lower nozzle brick, and sliding brick 8 and lower nozzle brick 9 are iron shell 10
It is covered with water so that it can move horizontally as a unit.

In the molten metal container 1 equipped with such a sliding type nozzle, the molten metal 4 is directly poured into the molten metal container 1 while the sliding brick 8 is moved to the right as shown in the figure to close the nozzle. When transferred, the supplied molten metal is transferred to the nozzle part brick 5, the upper nozzle brick 6. Fixed brick7. Contact with the sliding bricks 8, etc., and the metal will be rapidly cooled and solidified, causing a suspended state, narrowing or blocking the opening of the nozzle portion, and reducing the subsequent flow rate of the molten metal 4. Alternatively, there is a problem in that it may become impossible for the molten metal 4 to flow out itself.

Therefore, in order to solve this problem, before transferring the molten metal 4 into the molten metal container 1, as shown in the attached figure, the inside of the nozzle parts such as the upper nozzle brick 6 and the fixed brick 7, etc. A filling material 11 made of powdery refractory material or the like was filled in advance to prevent the molten metal 4 from solidifying in this area.

By the way, in such a method of filling the filling material 11, when the sliding brick 8 is moved to the left in the figure to cause the molten metal 4 to flow out, the filling material 11 falls and opens naturally. It is necessary to make sure that

(Problems to be Solved by the Invention) In this method of filling the filling material 11, the filling material 11
Although it is possible to prevent the molten metal 4 from solidifying at the nozzle part compared to the case where the molten metal 4 is not filled, the filling material 11 may sometimes be sintered by the heat from the molten metal or by the intrusion of the molten metal. , and also expands due to the heat of the molten metal.

After that, when the sliding brick 8 was moved to the left in the drawing to cause the molten metal 4 to flow out, the filling material 11 fell naturally and was not discharged smoothly.

Since the sliding nozzle may not open naturally, there is a problem in that it is necessary to open the opening by blowing oxygen, resulting in a significant decrease in work efficiency.

This invention was made by focusing on the above-mentioned problems of the conventional art.When filling the upper part of the sliding nozzle of a molten metal container with a filler material, after storing the molten metal in the molten metal container, the sliding nozzle When the filling material is opened to let the molten metal flow out, the filling material can be discharged and the molten metal can be discharged extremely smoothly, and the natural porosity of the sliding nozzle when the filling material is used is significantly improved. The purpose is to make it possible to do so.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a method for filling the filling material made of powdery refractory material into the upper part of the sliding nozzle of a molten metal container equipped with a sliding nozzle on the bottom surface. 2 filling materials
It is characterized in that it is heated to 00° C. or higher, more preferably 250 to 350° C. for filling.

The molten metal container 1 to which this invention is applied includes, but is not particularly limited to, a tundish or ladle for continuous casting, and the detailed structure of the sliding nozzle is also not particularly limited, and is schematically shown in the attached drawings. The one shown and other sliding nozzle systems also apply to.

Furthermore, the filling material 11 is made of powdery refractory material,
For example, ceramic grains such as silica sand grains, graphite grains, chromite grains, alumina grains, and other appropriate auxiliary agents (hygroscopic agents, lubricating oil, etc.) are used, and the particle size is adjusted appropriately. In the case of river or coastal silica sand, it is also desirable to remove iron sand.

When such a filling material 11 is supplied to the nozzle portion of the molten metal container 1, it is heated in advance to 200° C. or higher, more preferably 250 to 350° C., and then stored therein.

Therefore, since the molten metal 4 subsequently transferred into the molten metal container 1 does not enter the nozzle part as in the conventional case, it does not solidify in that part, and since the filling material 11 is heated in advance, the molten metal 4 Since the amount of thermal expansion when heated by is small, the filling material 11 is not packed excessively. The material 11 can be discharged and the molten metal 4 can be discharged extremely smoothly.

(Example) After preheating the molten metal container 1, a filling material 11 made of silica sand that has been sieved to adjust the particle size and heated to around 250° C. is placed on the top of the sliding nozzle of the molten metal container 1 on the top surface of the nozzle brick 5. It was filled to about the same level.

Next, when the molten metal 4 was put into the molten metal container 1 and the sliding nozzle 8 was moved to the left in the figure to open the sliding nozzle, the filling material 11 was naturally discharged very smoothly.

The molten metal 4 can also flow out smoothly, and the filling material 11
When the filling material 11 was not preheated, the natural porosity of the sliding nozzle was around 70%, but when the filling material 11 was
In the case of this example, which was heated to around .degree. C., excellent results were obtained in which the natural porosity of the sliding nozzle exceeded 90%.

[Effects of the Invention] As described above, according to the present invention, when filling a filling material made of powdery refractory material into the upper part of the sliding nozzle of a molten metal container equipped with a sliding nozzle on the bottom surface, the filling material is Because the filling material is heated to 200°C or higher, the amount of thermal expansion of the filling material filled into the sliding nozzle portion due to subsequent contact with molten metal is small, so a bridging phenomenon may occur at the sliding nozzle portion. This eliminates this problem, and when the sliding nozzle is opened, the filling material and molten metal can be smoothly discharged, and the natural porosity of the sliding nozzle can be significantly improved. A significant effect is brought about in that it is possible to improve the operating efficiency and yield during ingot making.

[Brief explanation of drawings]

The attached drawing is an explanatory cross-sectional view of the main part of the bottom of the molten metal container, showing a state in which the sliding nozzle part is filled with a filler material. 1... Molten metal container, 4... Molten metal, 5... Nozzle part brick, 6... Upper nozzle brick, 7... Fixed brick, 8... Sliding brick. 9... Lower nozzle brick, 11... Filling material.

Claims (1)

[Claims] (1) When filling a filling material made of powdery refractory material into the upper part of the sliding nozzle of a molten metal container equipped with a sliding nozzle on the bottom surface, the filling material is heated to 200°C.
A method of filling a filling material for a sliding nozzle, which is characterized by heating the filling material to the above temperature and filling the filling material.