JPS6124453B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for attaching a bottom blowing nozzle for upper and lower blowing, and a dummy nozzle for attachment.

In recent years, top-bottom blowing, in which oxygen is blown from a top-blowing lance and stirring gas is blown from below the surface of the steel bath, has become popular in converter steelmaking. The blowing of the stirring gas from below the surface of the steel bath is carried out by means of a downward blowing nozzle provided in the furnace body. This downward blowing nozzle is provided with a hole in the steel shell and lining brick, and is attached to the hole by a flange or the like. A sleeve brick is laid around the nozzle, and a monolithic refractory such as mortar is further filled between the sleeve brick and the lining brick.

When installing such a downward blowing nozzle to the furnace body,
There was a problem in that the nozzle could be damaged due to the installation of the sleeve bricks described above. Furthermore, when replacing the bottom blow nozzle in hot conditions, there was a problem in that it was impossible to fix and tighten the sleeve brick because the work was done from outside the furnace body.

This invention was made in view of these problems, and provides a method for easily centering and tightening sleeve bricks without damaging the bottom blow nozzle when installing or replacing the bottom blow nozzle. The present invention aims to provide a method for attaching a downward blow nozzle and a dummy nozzle for attachment.

In the present invention, first, a dummy nozzle having approximately the same external shape and dimensions as the downward blowing nozzle to be installed is prepared. An example is shown in FIG. 1
2 is a shell of the furnace body, and 2 is a nozzle mounting flange provided on the shell 1. A is a dummy nozzle, and a sleeve brick 4 is attached to this dummy nozzle A for centering, and the sleeve brick 4 is inserted into the hole of the steel shell 1 as it is. The flange of the dummy nozzle A and the mounting flange 2 are connected, and a monolithic refractory such as mortar is filled between the sleeve brick 4 and the lining brick 3 of the furnace body. When this work is completed, the dummy nozzle A is pulled out together with the flange 10 by loosening the bolts, and the downward blowing nozzle to be installed is inserted into the sleeve brick 4 to complete the installation.

According to the installation method using a dummy nozzle as described above, since the bottom blow nozzle used in actual operation is not used during bricklaying, there is no risk of damaging it.

Next, FIG. 2 shows a dummy nozzle that is preferable for performing hot nozzle exchange. This dummy nozzle B is
It is composed of an outer tube 5 and an inner tube 6 that is removably inserted into the outer tube 5. A flange 50 is provided at the end of the outer tube 5 outside the furnace, and this is attached to the mounting flange 2. A presser plate 7 for holding and pressing the sleeve brick 4 is provided at the inner end of the inner tube 6 on the inner side of the furnace, as will be described later. Inner tube 6
The other end on the outside of the furnace protrudes outside the outer tube 5 and is provided with a fastening fitting 8. In this embodiment, the fastening fitting 8 is a threaded portion 8 formed at the end of the inner tube 6.
0 and the nut 81 and washer 8 screwed onto it
2, fixing the inner tube 6, and sleeve brick 4.
Tighten in the axial direction.

The external shape formed by the outer tube 5 and the inner tube 6 is approximately the same shape as the downward blowing nozzle to be installed. In this embodiment, the bottom blow nozzle has a small diameter tip, so the inner tube 6 is exposed on the surface, but in the case of a normal straight bottom blow nozzle,
The entire inner tube 6 may be housed within the outer tube 5, and the outer tube 5 may have the same outer shape as the downward blowing nozzle.

Note that 9 is an eye bolt provided at the tip of the inner tube 6 in the furnace, and is used for handling the brick dummy nozzle set product.

Next, how to use the dummy nozzle having the above configuration will be explained.

First, the inner tube 6 is inserted into the sleeve brick 4 outside the furnace, and then the outer tube 5 is inserted. Then, the fastener 8 is tightened to fix the inner tube 6, and the sleeve brick 4 is tightened to complete the setting. The set dummy nozzle B and sleeve brick 4 are assembled into the lining brick 3 of the furnace body, and the flange 50 is attached and fixed to the flange 2. Then sleeve brick 4
A monolithic refractory material such as mortar is filled between the lining bricks 3 and the lining bricks 3, and after the furnace is heated, the dummy nozzle is dismantled and removed. The outer tube 5 is removed to the outside of the furnace, and the inner tube 6 is removed to the inside of the furnace. After removing the dummy nozzle, attach the bottom blow nozzle. At this time, sleeve brick 4
Since the centering of the nozzle has been completed and the nozzle is installed after the bricks 4 are laid, the nozzle can be easily installed without being damaged.

As explained above, according to the method and dummy nozzle of the present invention, excellent effects such as centering and tightening of the sleeve brick can be easily performed without damaging the bottom blowing nozzle.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a furnace bottom and a dummy nozzle for explaining the method of the present invention, and FIG. 2 is a cross-sectional view showing another embodiment of the dummy nozzle according to the present invention. In the figure, 1 is a steel shell, 2 is a mounting flange, 3 is a lining brick, 4 is a sleeve brick, A is a dummy nozzle for a new furnace, B is a dummy nozzle for hot use, 5 is an outer pipe, 6 is an inner pipe, 7 8 is a holding plate, 8 is a fastening metal fitting, 9 is an eye bolt, 10 and 50 are flanges, 80 is a threaded portion, 81 is a nut, and 82 is a washer.

Claims (1)

[Claims] 1. A dummy nozzle having almost the same shape as the downward blowing nozzle to be installed is attached to the furnace body and bricklaying is carried out, and then the dummy nozzle is removed and the downward blowing nozzle is attached. How to install the bottom blow nozzle. 2. An outer tube having a flange that is connected to the iron shell of the furnace body, an inner tube that is removably inserted into the outer tube, a sleeve brick press plate provided at one end of the inner tube, and an inner tube that is removably inserted into the outer tube. and a fastening fitting provided at the other end of the tube for tightening and fixing the inner tube in the axial direction, and the external shape of the outer tube or the outer tube and the inner tube is approximately the same as that of the downward blowing nozzle to which it is attached. A dummy nozzle for attaching a bottom blowing nozzle for top and bottom blowing, characterized by its shape.