JPS6347324A - Detection of slag level - Google Patents

Abstract

PURPOSE:To enable quick and exact quantitative detection of a slag level by providing plural projectors and receivers for projection waves horizontally in multiple stages so as to face each other to the wall of a converter and measuring continuously the projection waves from the projectors with the receivers. CONSTITUTION:Holes 4a-4c are provided horizontally in multiple stages at prescribed intervals to one side of the wall 1a of the converter 1 above a molten steel 2. The microwave projectors 7-9 are installed therein. The microwave receivers 19-21 are horizontally installed in multiple stages through holes 16-18 to the other side of the wall 1a so as to face the projectors 7-9. The microwaves A-C are projected from the projectors 7-9 by microwave transmitting sources 13-15 in the above-mentioned constitution and the signal values thereof are continuously received by the receivers 19-21 and are displayed via receiving sources 25-27 on signal detectors 28-30. Then the slag level 3a fluctuates and rises to shut off the microwaves C, B, A, successively, when the foaming of the slag 3 in the converter 1 progresses. The detected signal values are thereby changed and the slag level 3a is exactly detected.

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, the working environment deteriorates, such as reduced work efficiency, reduced calories in exhaust gas, and generation of red smoke.

In addition, various problems such as damage to the device occur.

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

A method of estimating the amount of slag in the converter based on the components of the exhaust gas generated during refining, and using the estimated amount of slag to predict the occurrence of sloshing.

However, this method has the following problems.

■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 when the pressure inside the furnace changes due to the amount of oxygen being fed, etc., so it is not possible 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 of capturing the radiant energy in the upper and lower parts of the converter body as temperature and predicting the occurrence of slow sobbing from the temperature change.

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 detect the occurrence of slopping. 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, in the method of measuring the amount of slag forming using a microwave level meter, a sensor 32 consisting of a water-cooled protection tube 33 and a waveguide 34 is installed vertically in the furnace mouth of a converter 37.

A microwave level meter 31 consisting of a microwave generator 35 and a signal processing device 36 connected to a sensor 32 is provided outside the converter 37, and the microwave generator 35 applies microwaves to the molten steel 2 in the converter 37. The beam is projected toward the slag 3 floating on the surface, its reflected wave is captured, and the signal processing device 36 measures the amount of forming of the slag 3 to measure the slag level.

However, in this method, since the sensor 32 is located at the mouth of the converter 37, it may come into contact with dust generated from the converter 37 during refining and be affected by the heat of the flame.
There is a problem that the sensor 32 is severely damaged.

[Purpose of the invention]

As described above, in order to predict the occurrence of slopping, it is necessary to understand the state of slag in the converter, and for that 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]

This invention provides a first hole horizontally penetrating the converter wall on one side of the converter wall, a projector for projecting waves is installed in the first hole, and the first hole facing the first hole A second hole passing through the furnace wall horizontally is provided on an extension of the first hole on the other side of the furnace wall, and a receiver for the projected wave is installed in the second hole at a position horizontal to the projector. A projected wave is horizontally projected from the projector toward the receiver, and the signal value of the projected wave is continuously detected by the receiver to detect fluctuations in the slag level that occur during refining of the converter. Therefore, the slag level in the converter is detected by the change in the signal value caused by the slag on the surface of the molten steel blocking the projected wave.

[Structure of the invention]

Next, the method of the present invention will be explained with reference to the drawings. g
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 l,
Above the surface of the molten steel 2 in the converter 1.

Three first holes 4, 5.6 are provided horizontally through the furnace wall 1 at predetermined intervals in the height direction of the converter 1.

Inside the first hole 4 there is a microwave projector 7 on the outside thereof, and on 4 a a microwave projector 7.
A microwave projector 8 is similarly installed on the outside 5a of the first hole 5, and a microwave projector 9 is similarly installed on the outside 6a of the first hole 6.

An inert gas blowing nozzle 1O for sealing the first hole 4 is provided at the top of the inside 4b inside the first hole 4, and a nozzle 11 is similarly provided at the top of the inside 5b inside the first hole 5. However, a nozzle 12 is similarly provided at the upper part of the inner side 6b within the first hole 6.

The inert gas blown into the first hole 4 from the nozzle 10 causes the molten steel 2 and formed slag 3 to flow into the first hole 4.
The inert gas blown into the first hole 5 from the nozzle 11 purges the molten steel 2 and forming Li slag 3 from entering the first hole 5, Similarly, the inert gas blown into the first hole 6 from the nozzle 12 prevents the molten steel 2 and the formed slag 3 from entering the first hole 6.

A microwave source 13 located outside the converter 1 is connected to the microwave projector 7, a microwave source 14 is connected to the microwave projector 8, and a microwave source 14 is connected to the microwave projector 9. A microwave source 15 is connected.

On the other side of the furnace wall 1a facing each of the holes 4, 5.6, there is a second hole 16°17.18 that horizontally penetrates the furnace wall 1a.
are provided on an extension line of the first holes 4, 5.6.

A microwave receiver 19 is installed on the outside 16a of the second hole 16 at a position horizontal to the microwave projector 7.
Similarly, a microwave receiver 20 is placed on the outside 17a inside the 7.
Similarly, a microwave receiver 21 is installed on the outside 18a inside the second hole 18.

An inert gas blowing nozzle 22 for sealing the second hole 16 is provided at the upper part of the inner side 16b in the second hole 16, and a nozzle is similarly provided at the upper part of the inner side 17b in the second hole 17. 23 is on the upper part of the inner side 18b in the second hole 18,
A nozzle 24 is likewise provided.

The inert gas blown into the second hole 16 from the nozzle 22 prevents the molten steel 2 and formed slag 3 from entering the second hole 16 .

Then, the inert gas blown into the second hole 17 from the nozzle 23 prevents the molten steel 2 and the formed slag 3 from entering the second hole 17, and similarly, the inert gas is blown into the second hole 17 from the nozzle 24. The inert gas blown into the hole 18 prevents the molten steel 2 and the formed slag 3 from entering the second hole 18 .

A microwave receiving source 25 and a signal detector 28 located outside the converter l are connected in series to the microwave receiver 19, and a microwave receiving source 26 and a signal detector 29 are similarly connected to the microwave receiver 2o. are connected in series, and the microwave receiver 21 is also connected in series with a microwave receiving source 27 and a signal detector 3°.

The horizontal microwave A projected from the microwave projector 7 by the microwave source 13 is transmitted to the microwave receiver 1.
Received on 9th. The microwave receiver 19 receives and continuously measures the signal value of the microwave A, and the signal value is
The signal is detected by the signal detector 28 and displayed.

The horizontal microwave B projected from the microwave projector 8 by the microwave source 14 is transmitted to the microwave receiver 2.
0 is received. The microwave receiver 20 receives and continuously measures the signal value of the microwave B, and the signal value is
The signal is detected by the signal detector 29 and displayed.

The horizontal microwave C projected from the microwave projector 9 by the microwave source 15 is received by the microwave receiver 21 . The microwave receiver 21 receives and continuously measures the signal value of the microwave C, and the signal value is
The signal is detected and displayed by the signal detector 3o.

As shown in FIG. 1, immediately after the converter 1 starts operating.

Slag 3 floats on the surface of molten steel 2 in 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 detected signal values of microwaves A, B, and C. As shown in FIG. 2, the cis slag level 3a fluctuates and rises due to the forming of the slag 3, and when it reaches the microwave C.

The slug 3 blocks the microwave C and changes the detection signal value of the microwave C.

Furthermore, when the slag level 3a fluctuates and rises and reaches the microwaves B and A, the slag 3 changes to the microwave B, respectively.
, A are cut off, and the detected signal values of microwaves B and A are changed.

In this way, the slag level in the converter 1 can be accurately detected by reading changes in the detection signal values of the microwaves C%E and A.

〔Effect of the invention〕

As explained above, according to the method of the present invention, the slag level in the converter can be detected accurately and quickly.

Therefore, the condition of the slag in the converter can be accurately grasped and the occurrence of slopping can be predicted, so by changing the operating conditions of the converter, for example by adjusting the amount of oxygen blown into the lance, Slopping can be prevented.

As described above, the present invention brings about a number of industrially useful effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view showing an embodiment of the method of the present invention, FIG. 2 is a diagram showing changes in microwave detection signal values, and FIG. 3 is a diagram showing a conventional method for measuring the amount of slag forming. It is a schematic vertical sectional view showing one example. In the drawing. 1... Converter 2... Molten steel 3... Slag 3a... Slag level 4, 5, 6°゛° 1st hole 7, 8.9... Microwave projector 10.1
1.12... Nozzle 13.14.15... Microwave source 16.17.
18...Second hole 19.20.21...Microwave receiver 22, 23
, 24... Nozzle 25.26.27...Microwave receiving source 28, 29
, 30...Signal detector 31...Microwave level meter 32...Sensor 33...Water cooling protection tube 34...
...Waveguide 35...Microwave generator 36...Signal processing device 37...Converter A, B, C
...Microwave.

Claims (1)

[Claims] A first hole passing through the converter wall horizontally is provided on one side of the converter wall, a projector for projecting waves is installed in the first hole, and the other side of the converter wall facing the first hole is provided. A second hole horizontally penetrating the furnace wall is provided on an extension line of the first hole on the side, a receiver for the projected wave is installed in the second hole at a position horizontal to the projector, and the projector A projector wave is projected horizontally from the converter toward the receiver, and the signal value of the projector wave is continuously detected by the receiver. A slag level detection method, comprising: detecting a slag level in a converter based on a change in the signal value caused by the slag on the surface blocking the projected wave.