JPS6347323A - Slag level detection method - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for detecting slag level in a converter for predicting occurrence of slopping during converter refining.

[Prior art and its problems]

During refining in the converter, slag floating on the surface of the molten steel in the converter forms depending on various conditions such as the composition and viscosity of the slag, and the amount of oxygen in the slag. When such slag forming progresses excessively, so-called slopping occurs, which adversely affects the molten steel composition, total tapping yield, and the like. Furthermore, when slopping occurs, various problems occur, such as a decrease in work efficiency, a decrease in calories in exhaust gas, deterioration of the work environment such as generation of red smoke, and damage to equipment.

In order to prevent the occurrence of such slopping, it is necessary to quickly grasp the situation of slag in the converter and to operate the converter appropriately.

For this purpose, the state of slag in the converter has conventionally been grasped by the methods described in (1) to (5) below.

(1) Due to the components of exhaust gas generated during refining.

A method of estimating the amount of slag in the converter and predicting the occurrence of slopping based on the estimated amount of slag.

However, this method has the following first-order problem.

■Exhaust gas analysis and analysis takes time.

There is a delay in predicting the occurrence of slopping.

■The cause of slopping is not only due to the amount of slag, so the prediction accuracy is low.

(2) A method of predicting the occurrence of slopping by estimating the slag level based on changes in the frequency and intensity of the sound generated inside the converter.

However, this method has the following problems.

■It is not possible to quantitatively understand the slag level.

■The sound generated from inside the converter changes not only depending on the state of slag forming, but also depending on the amount of oxygen supplied, etc., and when the pressure inside the furnace changes, making it impossible to accurately determine the state of the slag and the slag level. .

(3) A method of predicting the occurrence of slopping by estimating the slag condition and slag level based on changes in the vibrations of the lance and furnace body and the transition of the waveforms that occur during converter refining.

However, this method has a problem in that the state of the slag and the slag level cannot be quantitatively determined.

(4) A method that captures the radiant energy at the upper and lower parts of the converter body as temperature, and predicts the occurrence of slopping from temperature changes.

However, this method has a problem in that the state of the slag and the slag level cannot be quantitatively determined.

(5) Microwaves are projected from the converter mouth toward the slag on the surface of the molten steel in the furnace, and the reflected waves are captured by a microwave level meter to measure the amount of slag forming and to detect the occurrence of sloping. How to predict.

FIG. 3 is a schematic vertical sectional view showing an example of the method for measuring the amount of slag forming using the microwave level meter shown in (5). As shown in FIG. 3, the method for measuring the amount of slag forming using a microwave level meter involves vertically disposing a sensor 10 consisting of a water-cooled protection tube 11 and a waveguide 12 in the furnace mouth of a converter 15.

A microwave level meter 9 consisting of a microwave generator 13 and a signal processing device 14 connected to a sensor 10 is provided outside the converter 15, and the microwave generator 13 transmits microwaves to the surface of the molten steel 20 inside the converter 15. The slag level is measured by projecting the wave toward the slag 3 floating on the ground, capturing the reflected wave, and measuring the amount of forming of the slag 3 using the signal processing device 14.

However, in this method, since the sensor 10 is located at the mouth of the converter 15, it may come into contact with dust generated from inside the converter 15 during refining and be affected by the heat of the flame.
There is a problem that the sensor 10 is severely damaged.

[Purpose of the invention]

As mentioned above, in order to predict the occurrence of slopping, it is necessary to understand the condition of slag in the converter.
For this purpose, it is necessary to understand the slag level.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for detecting the slag level in a converter for quickly, accurately, and quantitatively detecting the slag level in the converter in order to predict the occurrence of slopping.

[Summary of the invention]

In this invention, a magnetic field generating coil is buried in one side of the converter furnace wall, and a receiving coil is buried in the other side of the furnace wall facing the magnetic field generating coil at a position horizontal to the magnetic field generating coil. A magnetic field is generated in the converter by the magnetic field generating coil, and the current value of the horizontal magnetic field is continuously measured by the receiving coil. Therefore, the slag level in the converter furnace is detected by the change in the current value caused by the slag on the surface of the molten steel blocking the horizontal magnetic field.

[Structure of the Invention] Next, the method of the present invention will be explained with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing one embodiment of the method of the invention.

As shown in FIG. 1, on one side of the furnace wall 1a of the converter 1,
Above the surface of the molten steel 2 in the converter 1, three magnetic field generating coils 4a are installed at predetermined intervals in the height direction of the converter 1.
4b and 4C are buried.

A power source 5a located outside the converter 1 is connected to the magnetic field generating coil 4a, a power source 5b is also connected to the magnetic field generating coil 4b, and a power source 5C is also connected to the magnetic field generating coil 4C. has been done.

Power supplies 5a, 5b, 5c are coils 4a, 4b, 4c
An alternating current is applied to each of them.

On the other side of the furnace wall 1a facing each of the magnetic field generating coils 4a, 4b, 4c, there are magnetic field generating coils 4a, 4b, 4.
Receiving coils 5a, 5b, and 6e for measuring the current value of the magnetic field generated in the converter 1 are buried in horizontal positions with the magnetic field generating coils 4a, 4b, and 4c, respectively. .

An amplifier 7a and an ammeter 8a located outside the converter 1 are connected in series to the receiving coil 6a, and an amplifier 7b and an ammeter 8b are also connected in series to the receiving coil 6b. Similarly, an amplifier 7c and an ammeter 80 are connected in series to 6c.

Power supplies 5a, 5b, 5c υ, magnetic field generation coil 4a,
When electricity is applied to each of 4b and 4c, the magnetic field generating coil 4
A magnetic field is generated at each of a, 4b, and 4c.

The magnetic field generating coils 4a and 4b, and 4b and 4C should be provided at appropriate intervals so that the respective generated magnetic fields do not interfere with each other.

The receiving coil 6a continuously measures the magnetic field generated by the magnetic field generating coil 4a, and calculates the horizontal magnetic field A.
The current value is displayed on the ammeter 8a.

The receiving coil 6b continuously measures the magnetic field generated by the magnetic field generating coil 4b, and calculates the horizontal magnetic field B.
The actual current value is displayed on the ammeter 8b.

The receiving coil 6C continuously measures the magnetic field generated by the magnetic field generating coil 4C, and calculates the horizontal magnetic field C.
The current value is displayed on the ammeter 80.

As shown in FIG. 1, immediately after the converter 1 starts operating, the slag 3 floats on the surface of the molten steel 2 in the converter 1.

After a certain period of time has passed after the start of operation of the converter 1, the forming of the slag 3 in the converter 1 progresses, and the slag level 3a changes.

FIG. 2 is a diagram showing changes in current values of magnetic field A, magnetic field B, and magnetic field C. As shown in Figure 2.

The slag level 3a fluctuates and rises due to the forming of the slug 3, and when it reaches the magnetic field C, the slag 3 blocks the magnetic field C and changes the current value of the magnetic field C.

Furthermore, the slag level 3a fluctuates and rises.

When reaching the magnetic fields B and A, the slug 3 blocks the magnetic fields B and A, respectively, and changes the current values of the magnetic fields B and A.

In this way, by reading changes in the current values of the magnetic field C1, magnetic field B, and magnetic field A, the slag level in the converter 1 can be accurately detected.

〔Effect of the invention〕

According to the method of the present invention as explained above.

The slag level in the converter can be detected accurately and quickly. Therefore, the condition of slag in the converter can be accurately grasped, and the occurrence of slopping can be predicted.
Slopping can be prevented by changing the operating conditions of the converter, for example by adjusting the amount of oxygen blown in by the lance. As mentioned above, according to this invention,
A number of industrially useful effects are brought about.

[Brief explanation of the drawing]

Figure 1 is a schematic vertical sectional view showing an embodiment of the method of the present invention, Figure 2 is a diagram showing changes in the current value of the magnetic field, and Figure 3 is an example of a conventional method for measuring the amount of slag forming. It is a schematic vertical cross-sectional view shown. In the drawings, 1... Converter 2... Molten steel 3... Slag 3a... Slag level 4a, 4b, 4c.
・・Magnetic field generation coil sa, sb, sc'' Power supply 6a
, 6b, 6cm... Receiving coil 7a, 7b, 7cm...
・Amplifier 8a, 8b, 8C...Ammeter 9...Microwave level meter 10...Sensor 11...Water cooling protection tube 12...Waveguide 13...Microwave generator 14...・Signal processing device 15...Converter A, B, C・
··magnetic field.

Claims (1)

[Claims] A magnetic field generating coil is buried in one side of the converter furnace wall, a receiving coil is buried in the other side of the furnace wall facing the magnetic field generating coil at a position horizontal to the magnetic field generating coil, and the magnetic field generating coil is buried in a position horizontal to the magnetic field generating coil. A magnetic field is generated in the converter by a generating coil, and the current value of the horizontal magnetic field is continuously measured by the receiving coil, due to fluctuations in the slag level that occur during refining of the converter. A slag level detection method, comprising detecting a slag level in a converter based on a change in the current value caused by slag on the surface of molten steel blocking the horizontal magnetic field.