RU2460808C1 - Method for metal blowing in steel pouring ladle - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method involves steel blowing with inert gas at least through two tuyeres. Acoustic vibrations with frequency of 500-1000 Hz are superimposed on inert gas jet of one tuyere. Acoustic vibrations with frequency of 2000-3500 Hz are superimposed on inert gas jet of the other tuyere.

EFFECT: improving steel quality, shortening the time of its treatment in ladle, and increasing the stability of tuyeres.

1 dwg

Description

The invention relates to metallurgy, in particular to out-of-furnace treatment of liquid metal in a ladle by purging it with an inert gas.

Known methods for purging metal in a steel pouring ladle, namely, that the inert gas is supplied through the purge tuyeres, at least two, installed in the bottom of the bucket. At the same time, the purge gas supplied through the tuyeres drives the layers of liquid metal, creating conditions for better mixing of both the metal and the additional materials specified in the bucket.

A known method of mixing steel in a ladle, providing a pulsating oscillation on the purge gas according to a sinusoidal law (patent No. 2304172). The use of this purge method speeds up the processing time, reduces the consumption of materials added to the bucket.

Closest to the proposed method is a method of purging liquid metal (patent No. 2376390), providing a combined effect on the purge gas: acoustic and pulsating. Moreover, acoustic vibrations are in the range of 100-5000 Hz, and the frequency of pulsating oscillations is in the range of 30-60 1 / min. The application of this method reduces the duration of the purge and the flow rate of the purge gas, increases the durability of the purge assembly and the bottom of the bucket.

The disadvantage of these methods is the damping power of the pulsating oscillations at the time of reducing the flow of purge gas, which is inevitable when the pneumatic device through which the purge gas passes. Reducing the purge gas flow rate reduces the efficiency of the removal of non-metallic inclusions and gases in the treated metal.

The technical result of the invention is to increase the intensity of macro-mixing of the metal in the bucket as a result of the effect on the size of the bubbles floating in the metal, which ensures the intensification of both the removal of non-metallic inclusions from the metal and the gases dissolved in the metal.

The solution to this problem is achieved due to the fact that in the method of purging steel in a ladle, including purging the steel with an inert gas through at least two purge tuyeres, acoustic vibrations of a certain frequency are superimposed on each inert gas stream emanating from the purge tuyeres. Acoustic vibrations with a frequency of 500-1000 Hz are superimposed on a stream of inert gas emanating from one blowing lance, and acoustic vibrations with a frequency of 2000-3500 Hz are superimposed on an inert gas stream emanating from a second purge lance.

Acoustic vibrations with a frequency of 500-1000 Hz are superimposed on the purge gas of one lance. Acoustic vibrations with a frequency of 2000-3500 Hz are superimposed on the purge gas of another lance.

At low frequencies (500-1000 Hz) of acoustic vibrations, large gas bubbles form, which, rising up, entrain adjacent layers of metal and, therefore, contribute to the mixing of metal in the bucket.

An increase in the frequency of acoustic vibrations to 2000-3500 Hz leads to a decrease in the size of the bubbles, which means that it becomes possible to create conditions for the effective removal of non-metallic inclusions and metal degassing in the bucket.

Figure 1 shows a device that implements this method. It consists of a steel pouring bucket (1), in the bottom of which there are purge lances (2), an acoustic emitter of low frequency (3), an acoustic emitter of high frequency (4), shutoff valves (5), a purge gas supply pipe (6).

The method is as follows.

The metal released from the furnace is transferred in a steel-pouring ladle to an out-of-furnace treatment unit for liquid metal steel to bring it to the required quality. A purge gas, such as argon, is supplied through a pipe (6) to the purge lances (2) through acoustic emitters (3, 4). Passing through the acoustic emitter (3), acoustic vibrations with a frequency of 500-1000 Hz are superimposed on the purge gas stream. Passing through the acoustic emitter (4), acoustic vibrations with a frequency of 2000-3500 Hz are superimposed on the purge gas stream.

Depending on the particularity of smelting during metal processing, various technological methods are used in the ladle, including the regulation of the purge gas flow rate for one or the other lance, or both together, achieving the requirements for the metal being processed.

The application of this method improves the quality of the metal, reduces the processing time of the metal in the bucket, and increases the resistance of the blowing tuyeres.

Claims (1)

The method of purging metal in a steel pouring ladle, including purging the steel with an inert gas through at least two blowing tuyeres, while acoustic vibrations are applied to each inert gas stream emanating from the blowing tuyeres, characterized in that the inert gas stream emanating from one blowing gas lances impose acoustic vibrations with a frequency of 500-1000 Hz, and acoustic vibrations with a frequency of 2000-3500 Hz impose on an inert gas stream emanating from a second purge lance.