JPH05320732A - Method for removing stuck material in bottom blowing converter - Google Patents

Abstract

PURPOSE:To simply and surely remove and recover the stuck material in a furnace by inserting a top-blowing lance through a furnace opening part during blowing oxygen in a bottom blowing converter, vertically ascending/descending the top-blowing lance under rotating and blowing oxygen. CONSTITUTION:During the blowing operation in the bottom-blowing converter 1, the top-blowing lance 2 for oxygen blowing is inserted through the furnace opening part 1a of the converter 1. This lance 2 is vertically shifted while rotating or swinging and oxygen is blown toward the stuck material (f) in the converter 1 from at least one piece of a lance tip 2a arranged at the tip part of the lance. By this method, the stuck material (f) developed in the converter 1 can simply and quickly be removed and recovered in the condition of continuing the blowing operation, and the lowering of the productivity and the yield is avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing in-furnace deposits in a bottom-blowing converter, which effectively removes deposits such as metal ingots generated during blowing in the bottom-blowing converter. It is about to be collected.

[0002]

2. Description of the Related Art In the operation of a converter, metal is remarkably deposited in the region from the furnace wall to the furnace mouth due to splashing during blowing. Such deposits reduce the volume of the converter and reduce its processing capacity.Therefore, it is necessary to remove the deposits. A method of secondarily burning the exhaust gas in the furnace to dissolve the deposits is adopted. Documents relating to this point include JP-A-55-50143 and JP-B-56.
-5810 publication etc. are referred to.

[0003]

By the way, the above-mentioned Japanese Patent Laid-Open No.
In the technology disclosed in Japanese Patent No. 55-50143, there is a problem that productivity is unavoidable because the converter to be applied is a top blowing converter and it is necessary to perform it during non-blowing when blowing oxygen. .. This technology also applies to decarburization lances and metal melting lances.
(Oxygen blowing) is required for each, so the equipment cost is high, and the molten metal is discharged to the slag pot and cannot be recovered as molten steel. It was

On the other hand, in the technique disclosed in Japanese Patent Publication No. 56-5810, since the tuyere on the top of the furnace is separately provided, the cost increase is inevitable, and even when the amount of deposits is small. From the viewpoint of preventing tuyere blockage, it is necessary to constantly blow oxygen from the tuyere at the top of the furnace, so the refractory materials that make up the converter are severely melted, and the amount of blown gas used is also increased, which is a disadvantage. was there.

[0005] It is possible to propose a method for easily and surely removing the deposits of deposits on the side wall portion including the furnace opening, which occurs in the blowing using the bottom blowing converter. This is the purpose of this invention.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention arranged an upper blowing lance for secondary combustion in a bottom blowing converter in order to remove the deposits during blowing of the converter, thereby melting the deposits. Although the experiment was conducted, the dissolution rate of the deposits on the furnace mouth and that on the furnace wall did not balance (the deposits on the furnace mouth melted first), and the volume inside the furnace increased due to the remaining deposits on the furnace wall. It was difficult to plan. The present invention advantageously achieves the intended purpose by taking the following configurations.

That is, according to the present invention, an upper blowing lance for blowing oxygen is inserted through a furnace opening of a bottom blowing converter to vertically move while rotating or rotating the upper blowing lance during blowing of the bottom blowing converter. Then, oxygen is blown to the region from the side wall of the furnace to the furnace mouth, and the deposits adhered from the furnace wall to the furnace mouth are dissolved and removed. Is the removal method.

Now, FIG. 1 schematically shows the structure of an apparatus suitable for carrying out the present invention. In the figure, 1 is a bottom blow converter capable of blowing even if oxygen is not blown by an upper blow lance. Reference numeral 2 denotes an oxygen-injecting upper-blowing lance inserted through the furnace port 1a of the converter 1. The upper-blowing lance 2 has a drive mechanism for turning or rotating the lance itself and a lifting mechanism for vertically moving the lance. A mechanism is provided, and at least one lance tip 2a disposed at the tip thereof.
The oxygen can be blown toward the deposit f in the converter. Reference numeral 3 is a molten metal (hot metal) contained in the converter 1.

[0009]

In the present invention, during blowing by the bottom blowing converter 1, the upper blowing lance 2 is appropriately moved up and down while being rotationally driven to blow oxygen between the side wall of the furnace and the furnace port 1a. Since the kimono is removed, it is not necessary to remove the adhering matter after the molten metal has been blown, and therefore the productivity is not reduced. In addition, since the deposits that have fallen off the side wall of the furnace or the furnace mouth drop into the converter, they can be recovered as molten steel and the yield does not decrease.

In the present invention, it is indispensable to drive the upper blowing lance 2 to rotate or rotate, but this is to prevent oxygen from being locally concentrated and blown. It is advantageous to further extend the life of the product.

[0011]

EXAMPLE A bottom blowing converter (23 with a metal attached as shown in FIG. 2 in the region from the furnace opening to the center (about 3 m) of the furnace wall (23 m)
0 t) was charged with 230 t of hot metal and blown, and during the blow, oxygen was blown from the center of the furnace wall to the furnace mouth under the conditions shown in Table 1 by the upper blow lance. Then, the work of melting and removing the metal was performed.

[Table 1]

As a result, when oxygen is blown in accordance with the present invention, bare metal adherence is almost eliminated as shown in FIG. 3, and the steel production yield is compared with the case where only bottom blowing operation as shown in FIG. 2 is performed. It was confirmed that it improved about 3%.
On the other hand, when oxygen is simply blown onto the hot metal bath surface by the top blowing lance, although the dissolution of the metal in the furnace mouth is seen as shown in Fig. 4, the metal in the side wall of the furnace is Was not melted, the volume in the furnace could not be increased, and the yield of produced steel was only improved by about 0.5%.

[0013]

According to the present invention, even if metal is attached to the wall surface in the furnace during blowing by the converter, it can be removed easily and quickly while continuing the blowing operation. Therefore, the productivity is not lowered and the yield is not lowered.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of an apparatus suitable for carrying out the present invention.

FIG. 2 is a diagram showing a state of adhesion of metal in a converter.

FIG. 3 is a diagram showing a molten state of a metal in the case of blowing oxygen according to the present invention.

FIG. 4 is a diagram showing a molten state of a metal in the case where oxygen is blown using a conventional top blowing lance.

[Explanation of symbols]

 1 Bottom blowing converter 1a Furnace mouth 2 Top blowing lance 2a Lance tip 3 Hot metal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuya Higuchi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Co., Ltd. Chiba Works (72) Inventor Koichi Hayashi 1 Kawasaki-cho, Chuo-ku, Chiba-shi Address Inside Kawasaki Steel Co., Ltd. Chiba Works

Claims (1)

[Claims] 1. An upper blowing lance is inserted through a furnace opening of a bottom blowing converter to vertically move up and down while swirling or rotating during blowing of the bottom blowing converter to move up and down from a side wall of the furnace. A method for removing in-furnace deposits in a bottom blowing converter, which comprises melting and removing deposits such as metal that adheres to the region up to the furnace mouth by blowing oxygen.