JPH0763484A - Molten steel outlet nozzle on bottom of melting furnace - Google Patents

Abstract

PURPOSE:To perform replacement of a molten steel outlet nozzle within a short period of time by a method wherein the outside diameter of a lower nozzle is smaller than the inside diameter of a mounting hole, the upper end of a nozzle fitting blocks a gap between the mounting hole and nozzle blocks, and the nozzle fitting has feed holes through which mortar can be filled in the gap from outside a furnace. CONSTITUTION:The outside diameter of a lower nozzle 4 is smaller than the inside diameter of a mounting hole 2a. A nozzle fitting 5 surrounds the periphery of the lower nozzle 4 and has such a retaining construction that its upper end is leveled with the upper end of the lower nozzle 4. Therefore, the upper end of the nozzle fitting 5 can be in contact with the bottom face of a furnace bottom brick 2. Thereby, an annular gap produced around nozzle blocks 3 can be blocked by the nozzle fitting 5. The nozzle fitting 5 has two or more feed holes 5a through which mortar material is filled in the gap around the nozzle blocks 3 after the nozzle blocks 3 and the lower nozzle 4 are inserted into the furnace bottom bricks 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel output nozzle of a melting furnace used for melting scrap or the like or refining molten metal, and more particularly, it relates to a furnace bottom discharge which enables easy replacement of the nozzle. Regarding the structure of the steel nozzle.

[0002]

2. Description of the Related Art As a facility for melting scrap metal materials and refining molten metal, a melting furnace for immersing electrodes to melt and refine metals has been conventionally used. This melting furnace
The basic structure is that a slag opening is provided on one end side of the furnace, the whole furnace can be tilted with this slag opening side as a pivot point, and a tap hole is provided on the opposite side of the slag opening.

Various nozzles using a refractory material are replaceably incorporated in the tap hole. As this nozzle, one having a structure similar to that incorporated in various kinds of metal melt containers such as a tundish and a converter can be used. For example, the one described in Japanese Utility Model Laid-Open No. 63-41354 is an example, and a vertical sectional view thereof is shown in FIG.

A plurality of nozzle blocks 3 made of refractory are stacked in a plurality of furnace bottom bricks 2 laminated in an iron shell 1, and a lower nozzle 4 is arranged below the iron shell 1 at the lower end. The lower nozzle 4 is held by the nozzle pressing member 5 which is detachably attached to the iron shell 1, and forms a flow path from the nozzle block 3 to the lower nozzle 4.

In such a tapping hole, since the nozzle block 3 and the lower nozzle 4 are subject to melting loss and thinning with the number of tapping, it is necessary to replace the nozzle regularly. Then, in order to simplify the removal of the nozzle block 3 from the furnace bottom brick 2 and the installation of a new one, the inner diameter of the mounting hole 2a formed in the furnace bottom brick 2 is made larger than the outer diameter of the nozzle block 3 to form an annular gap. I am trying to have it.

[0006]

After the new nozzle block 3 and the lower nozzle 4 are installed, a gap remains around the nozzle block 3 and the inner wall of the mounting hole 2a, so that the mortar 6 etc. is left in this portion. Need to be filled.

However, since the lower end of the gap is closed by the nozzle retainer 5 holding the lower nozzle 4 and the lower nozzle 4 itself, this mortar 6 can only be filled from inside the furnace. For this reason, the work is carried out in a high heat furnace, which puts a heavy burden on the worker. In addition, since the replacement work cannot be done until the furnace cools, a decrease in the operating rate cannot be avoided and obstacles in terms of productivity cannot be ignored.

An object to be solved in the present invention is to provide a tapping nozzle capable of safely performing the nozzle replacement work from the outside of the furnace in a short time.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a plurality of nozzle blocks are laminated and incorporated in a mounting hole formed in a furnace bottom brick, and the lower nozzle is abutted against the lower surface of the lowermost nozzle block and the lower nozzle is attached to the lower nozzle block. A tapping nozzle that is provided with a nozzle retainer for holding on the furnace side, and is a tapping nozzle filled with mortar in the gap between the periphery of the nozzle block and the inner circumference of the mounting hole, and the outer diameter of the lower nozzle is larger than the inner diameter of the mounting hole. Make it smaller,
The upper end of the nozzle pressing piece is shaped to close the gap between the mounting hole and the nozzle block, and the nozzle pressing piece further comprises an injection hole capable of filling mortar from outside the furnace toward the gap. Characterize.

[0010]

In the lower end of the gap between the nozzle block and the mounting hole, the lower nozzle faces the nozzle retainer without interference, and the injection hole provided in the nozzle retainer makes the gap communicate with the outside of the furnace. Therefore, the work of filling the mortar through the injection hole can be performed from the outside of the furnace, and the work inside the furnace and the standby for lowering the temperature of the furnace are unnecessary.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vertical cross-sectional view showing a main part of a tapping nozzle in a melting furnace of the present invention.

In the figure, as in the conventional example, a furnace bottom brick 2 laminated on an iron shell 1 of a melting furnace is penetrated with a mounting hole 2a for assembling a nozzle, and a plurality of nozzle blocks 3 are assembled therein. At the same time, the lower nozzle 4 at the lower end is held by the nozzle pressing piece 5.

The outer diameter of the lower nozzle 4 is smaller than the inner diameter of the mounting hole 2a, and the nozzle pressing member 5 has a holding structure that surrounds the lower nozzle 4 and has its upper end aligned with that of the lower nozzle 4. The upper end of the presser foot 5 can be abutted against the lower surface of the furnace bottom brick 2. As a result, the annular gap formed around the nozzle block 3 is closed by the nozzle pressing member 5.

The nozzle block 3 has a nozzle block 3
After assembling the lower nozzle 4 into the furnace bottom brick 2, a plurality of injection holes 5a for filling the gap around the nozzle block 3 with the mortar material are opened. The injection hole 5a is opened obliquely below the nozzle retainer 5 and has an upper end opening located between the peripheral wall of the mounting hole 2a and the outer periphery of the nozzle block 3.

By providing the injection hole 5a in the nozzle pressing member 5, after removing the melted nozzle block 3 and the lower nozzle 4 and installing a new one, the mortar material is supplied to the injection hole 5a from outside the furnace. By
The mortar 6 can be filled and formed in the gap around the nozzle block 3.

As described above, the injection of the mortar material can be performed from outside the furnace by using the injection hole 5a provided in the nozzle pressing member 5, and it is not necessary for the worker to enter the furnace to perform the work, and the work load is reduced. Is reduced.

Further, during the replacement work, there is no need to wait for the temperature of the furnace to cool down or cool the inside of the furnace, so that the nozzle replacement work is shortened and the down time of the furnace is shortened.

[0018]

According to the present invention, mortar can be injected into the gap between the mounting hole and the nozzle block after the nozzle replacement work from outside the furnace. For this reason, the burden of the work inside the furnace is eliminated, and since it is not necessary to wait until the furnace is cooled, the replacement time and the down time of the furnace are shortened, and the productivity is improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a main part of a tapping nozzle in a melting furnace of the present invention.

FIG. 2 is a vertical sectional view showing a conventional tapping nozzle.

[Explanation of symbols]

 1 iron crust 2 furnace bottom brick 2a mounting hole 3 nozzle block 4 lower nozzle 5 nozzle retainer 5a inlet 6 mortar

Claims (1)

[Claims] 1. A nozzle presser for holding a plurality of nozzle blocks in a mounting hole formed in a furnace bottom brick by stacking them, abutting a lower nozzle on the lower surface of the lowermost nozzle block and holding the lower nozzle on the furnace side. A tapping nozzle filled with mortar in the gap between the periphery of the nozzle block and the inner periphery of the mounting hole, wherein the outer diameter of the lower nozzle is smaller than the inner diameter of the mounting hole, Furnace bottom tapping in a melting furnace having an upper end shaped to close a gap between the mounting hole and the nozzle block, and further comprising an injection hole capable of filling mortar from outside the furnace toward the gap in the nozzle presser metal nozzle.