JP2002356709A - Method for measuring slag layer thickness, and method and apparatus for measuring surface level positions of slag layer and molten metal layer surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slag layer thickness measuring method which is used for a converter and can measure the thickness of a slag layer at a low cost. SOLUTION: An electrode is elevated from a molten metal layer to an atmospheric layer through the slag layer. The change in the electric characteristic between the electrode and a vessel is measured by utilizing the difference of the electric characteristic of the molten steel layer filled in the vessel of the converter, the slag layer afloat on the surface of the molten steel layer and the atmosphere layer occupying an upper layer of the slag layer. The thickness of the slag layer is measured from the moving distance of the electrode therebetween.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a slag layer thickness or a slag layer thickness and a molten metal layer surface level position and a measuring apparatus therefor.

[0002]

2. Description of the Related Art In converters and the like used for refining steel from pig iron produced in a blast furnace, in order to control the refining,
It is necessary to measure the thickness of the slag layer floating on the surface of the molten steel. Therefore, using one or two electrodes,
The method of determining the thickness of the slag layer by measuring the difference in the impedance of molten steel, slag, and the atmosphere, and the thickness of the slag layer using the induction voltage of the electromagnetic coil that differs in molten steel, slag, and the atmosphere, respectively Is used.

[0003]

However, the measuring method using the difference in impedance is that the connection impedance of the lance connector holding the electrode cannot be neglected and the error is large. It is necessary to prevent damage when the electromagnetic coil is immersed in the molten steel, and the apparatus becomes large and expensive, which is a problem. The present invention has been made to solve such a problem, and an object of the present invention is to provide a method and an apparatus for measuring a slag layer thickness with a small error and low cost.

[0004]

Means for Solving the Problems Molten steel filled in a vessel such as a converter is mainly composed of a molten metal, and has electrical properties as a metal. The slag layer floating on the surface is an electrolyte, and it has been found that when an electrode is immersed in the slag layer, it exhibits characteristics as a battery. Moreover, the atmosphere occupying the upper layer of the slag layer has an insulating property as an electrical property, as is well known. The present invention has been made by paying attention to these points, and measures the thickness of the slag layer by utilizing the fact that the electrical characteristics of the slag layer are different from those of the lower molten steel and the upper atmosphere. What you want to do. The electrical characteristics of the slag layer described above are not limited to molten steel, but can be applied to molten metal in general. Therefore, the present invention is directed to molten metal.

[0005] A first method for measuring the thickness of a slag layer according to the present invention is as follows.
Specifically, the following method is used. That is, a method of measuring the thickness of the slag layer of the molten metal in which the slag layer floats on the surface of the molten metal layer, from the molten metal layer to the atmosphere layer occupying the upper layer of the slag layer through the slag layer. The electrode is moved upward to monitor an electrode-container characteristic, which is an electrical characteristic between the container containing the molten metal and having conductivity and the electrode, and the electrode-container characteristic is the electrode-container characteristic. When the electrode moves from the conductivity due to the interposition of the molten metal layer when immersed in the molten metal layer to the power generation property due to the interposition of the slag layer that moves to the slag layer and functions as an electrolyte. At a certain molten metal-slag interface passing time, at the time when the electrode escapes from the slag layer to the atmosphere layer, and the electrode-vessel characteristic shifts from the power generation property to the insulation property due to the interposition of the atmosphere layer. A certain slag-large Along with detecting the time at which the electrode passes, the molten metal-slag layer passes through the slag-atmosphere interface, and measures the distance traveled by the electrode to determine the slag layer thickness. This is a thickness measuring method.

FIG. 1 is an explanatory view showing the principle of the first slag layer thickness measuring method. In FIG. 1, 1 is a container, 2 is a molten metal layer, 3 is a slag layer, 4 is an atmospheric layer, and 5 is an electrode. As described above, the slag layer 3 is an electrolyte, and when the electrode is immersed therein, it exhibits characteristics as a chemical battery.
This is because cations (Si2 +, P2 +) in the molten slag
Etc.) and anions (O2-) exchange electrons through the electrodes to generate an electromotive force.

In the first slag layer thickness measuring method, the electrode 5 is moved upward from the molten metal layer 2 through the slag layer 3 to the atmosphere layer 4, and the electric current between the electrode 5 and the container 1 is set between the electrode 5 and the container 1. The thickness of the slag layer 3 is measured by utilizing the change in the characteristic between the electrode and the container, which is a characteristic, and FIG. 1 is an explanatory diagram of this measuring method. A container 1 such as a converter for containing a molten metal is generally formed by stacking refractory bricks inside a metal container, and the container 1 alone does not have conductivity. By containing the metal, the metal adheres to the inner surface of the container 1 so that the space between the inner surface of the container 1 and the ground becomes conductive. That is, the container becomes conductive. Therefore, by examining the electrical characteristics between the electrode 5 and the ground, the electrode-vessel characteristics that are the electrical characteristics between the electrode 5 and the container 1 can be examined. In this case, in FIG. 1, when the electrode 5 is located on the molten metal layer 2 (a), the molten metal layer 2 is in a molten state of the metal, so that the electrode-vessel characteristic is conductive. When the electrode 5 moves to the slag layer 3 (b), the characteristics between the electrode and the container become power generation as described above. When the electrode 5 moves through the slag layer 3 to the atmosphere layer 4 (c), the atmosphere intervenes, and the electrode-vessel characteristics become insulating. Therefore, when the electrode 5 is moved upward from the molten metal layer 2 to the atmosphere layer 4, the electrode 5
Molten metal layer 2 whose characteristics between containers change from conductive to power generating
The electrode 5 passes through the interface between the molten metal and the slag layer 3 at the time when the electrode 5 passes through the interface between the slag layer 3 and the slag layer 3 and the interface between the slag layer 3 and the atmosphere layer 4 where the characteristics between the electrode and the container change from power generation to insulation. Slag passing through the air interface 8 is detected,
During this time, the thickness of the slag layer 3 can be known by measuring the distance that the electrode 5 has moved upward.

In the first slag layer thickness measuring method,
Although the electrode 5 is moved upward, the electrode may be moved downward. In this case, the second slag layer thickness measuring method is a method of measuring the thickness of the slag layer of the molten metal in which the slag layer floats on the surface of the molten metal layer, and the air layer occupying the upper layer of the slag layer. From the electrode to the molten metal layer through the slag layer to monitor the electrode-container characteristics, which are the electrical characteristics between the container containing the molten metal and the electrode having conductivity. Then, the characteristics between the electrode and the container, due to the insulation due to the presence of the atmosphere when the electrode is in the air layer, the power generation due to the interposition of the slag layer, which immerses the electrode in the slag layer and functions as an electrolyte. At the time of transition to the atmosphere-slag interface, and the electrode moves from the slag layer to the molten metal layer, the electrode-
The container-to-container characteristic detects a slag-molten metal interface passing time, which is a point in time when the power generation property shifts to conductivity due to the interposition of the molten metal layer, and detects the slag-molten metal from the air-slag interface passing time. By the time of crossing the interface,
This is a slag layer thickness measuring method that measures a moving distance of the electrode and determines the thickness of the slag layer.

In the case of this second slag layer thickness measuring method,
The electrode is moved downward from the atmospheric layer through the slag layer to the molten metal layer, and the electrode-vessel interface changes from insulating to power generation. The passage point and the electrode passing through the slag-molten metal interface when the electrode passes through the interface between the slag layer and the molten metal layer where the characteristics between the electrode and the container change from power generation to electrical conductivity are detected. By measuring the distance moved, the thickness of the slag layer can be known as in the case where the electrode is moved upward.

According to the first slag layer thickness measuring method or the second slag layer thickness measuring method, the electrode-container characteristic, which is the electric characteristic between the electrode and the container, is changed. The measurement is performed by utilizing a change between certain conductive, power-generating, or insulating properties. This change is not a change between homogenous things like a change in impedance,
Since the changes are different from each other, the changes can be clearly recognized, and the thickness of the slag layer can be accurately measured. Further, since the electrode itself is not expensive in terms of cost, it may be replaced every time the measurement is performed, and it is not necessary to prevent the electrode from being damaged. A slag layer thickness measuring method can be provided.

In the first and second slag layer thickness measuring methods, the molten metal-
Slag layer thickness measurement that detects the slag interface passing time, slag-air interface passing time, air-slag interface passing time, or slag-molten metal interface passing time detection by measuring the potential of the electrode with respect to the container. A method is conceivable. First, a third slag layer thickness measuring method according to this method is the same as the above-described first slag layer thickness measuring method, except that a DC power supply Vcc having the electrode side as a cathode is provided between the electrode and the container. And a resistor Rx connected in series with this power supply
And, when the electrode is immersed in the slag layer, the value of the DC power supply Vcc and the value of the resistor Rx are set such that the potential of the electrode with respect to the potential of the container is higher than the reference potential. As well as high potential
The electrode is moved upward from the molten metal layer to the atmospheric layer to measure the potential of the electrode with respect to the reference potential, and the potential of the electrode is raised from the reference potential to the high potential as the time of passing the molten metal-slag interface. The slag layer thickness measurement is performed by detecting a point in time when the potential of the electrode changes from the high potential to a low potential lower than the reference potential, as a point in time when the potential changes to the slag-air interface. Is the way.

FIG. 2 is an explanatory view showing the structure of a measuring device used in the third slag layer thickness measuring method. FIG. 2 shows that a DC power supply Vcc11 having a cathode on the electrode 5 side and a resistor Rx12 connected in series with the power supply 11 are inserted between the electrode 5 and the container 1 in FIG. That is, a potential measuring means 13 for measuring a voltage between the electrode 5 and the container 1 is provided. Here, DC power supply 1
1 and the value of the resistor Rx12 are set such that the potential of the electrode 5 with the potential of the container 1 as the reference potential is higher than the reference potential when the electrode is immersed in the slag layer.

FIG. 3 shows an equivalent circuit of FIG. In FIG. 2, the movement of the electrode 5 between the molten metal layer 2, the slag layer 3 and the atmosphere layer 4 is the same as switching the changeover switch 19 in FIG. That is, when the electrode 5 is located on the molten metal layer 2 (a), since the molten metal layer 2 is in a molten state of metal, the electrode-vessel characteristic is conductive. A short circuit state occurs between the container 1 and the molten metal layer 2. When the electrode 5 is located on the slag layer 3 (b), the battery characteristics are shown because the slag layer 3 is an electrolyte.
In place of the slag layer 3 between the
At o, it is the same as when a battery with an internal resistance of Ro is connected. When the electrode 5 is located in the atmosphere layer 4 (c),
Since the atmosphere has an insulating property, the space between the electrode 5 and the container 1 is
It is open through the atmosphere layer 4. Equivalent circuits in each of these cases are shown in FIGS.
That is, in FIG. 2, the potential of the container 1 is set to the reference potential 0 (V).
When the electrode 5 is located on the molten metal layer 2 (a), when the electrode 5 is located on the slag layer 3 (b), or when the electrode 5 is located on the atmosphere layer 4 (c), Assuming that the potentials of the electrode 5 with respect to the reference potential are Va, Vb, and Vc, these are Va = 0 (V) (reference potential) and Vb = ( E
oRx−VccRo) / (Ro + Rx) (V), Vc = −
Vcc (V) (low potential lower than the reference potential). Here, Vb in FIG. 4B is a higher potential than the reference potential, which is higher than the potential of the container 1, which is the reference potential, by setting the values of the DC power supply Vcc and the resistance Rx described above. 4
The potential becomes positive with respect to the ground of (b). Generally,
Since Rx is on the order of several hundreds of ohms and the internal resistance Ro in the battery characteristics indicated by the slag layer 3 is on the order of tens to hundreds of ohms, Vb is substantially equal to Eo as shown in FIG. Since this electromotive force is positive with respect to the ground, Vb has a positive potential.

When the electrode 5 is moved upward from the molten metal layer 2 to the atmosphere layer 4 through the slag layer 3 using the above-described measuring circuit, the potential of the electrode 5 is set to the potential of the container 1 as a reference potential. Is obtained as shown in FIG. When the measurement is started at the point of time Ta and the electrode 5 is located on the molten metal layer 2 (a), Va is 0 (V). At the time Tb when the electrode 5 shifts from the molten metal layer 2 to the slag layer 3, that is, at the time of passing through the molten metal-slag interface, the potential becomes Vb plus potential.
Further, at the time Tc when the contact 5 shifts from the slag layer 3 to the atmosphere layer 4, that is, at the time of passing through the slag-air interface, Vc
At -Vcc (V), resulting in a negative potential. Then, when the time when the potential of the electrode 5 changes from 0 (V) to the positive potential, that is, the time when the potential changes from the reference potential to a higher potential higher than the reference potential, is detected, the time when the molten metal passes through the slag interface is detected. If the potential of the electrode 5 changes from a positive potential to a negative potential, that is, from a high potential higher than the reference potential to a low potential lower than the reference potential, the slag-air interface is detected. This means that the passage point has been detected. Then, based on these detections, the thickness of the slag layer 3 can be known by calculating the moving distance of the electrode 5 from the time of passing through the molten metal-slag interface to the time of passing through the slag-atmosphere interface.

In the third slag layer thickness measuring method,
Although the electrode is moved upward, the same principle can be used for measurement when the electrode is moved downward. In this case, the fourth slag layer thickness measuring method is the same as the above-mentioned second slag layer thickness measuring method, except that a DC power supply Vcc having the electrode side as a cathode is provided between the electrode and the container. And a resistor Rx connected in series with the DC power supply Vcc and the value of the resistor Rx, and the electrode with the potential of the container as a reference potential when the electrode is immersed in the slag layer. The potential is set to be a high potential higher than the reference potential, and the electrode is moved down from the atmospheric layer to the molten metal layer, and the potential of the electrode with respect to the reference potential is measured. The time at which the potential of the electrode changes from a low potential lower than the reference potential to the high potential as the time of passage through the atmosphere-slag interface, and the time at which the potential of the electrode passes through the high potential as the time of passage through the slag-molten metal interface. Electric potential This is a method of measuring the slag layer thickness by detecting the time when the slag changes to the reference potential.

According to the third slag layer thickness measuring method or the fourth slag layer thickness measuring method, the change in the potential of the electrode is determined by the reference potential and the high potential higher than the reference potential. This is a change to any of the lower potentials lower than the reference potential, and the change can be captured digitally, so that the change can be accurately detected. Since the moving distance can be accurately obtained, the thickness of the slag layer can be accurately known. Further, even if the impedance between the electrode and the container changes due to the contact resistance of a connector or the like connected to the electrode, the change in the potential of the electrode is the reference potential, the high potential higher than the reference potential, Since the change is still to any of the low potentials lower than the reference potential, the above-described measurement method can be said to be a method that is hardly affected by a change in impedance between the electrode and the container.

In the first, second, third, or fourth slag layer thickness measuring method, the moving distance of the electrode is directly measured.
From the time of passing the slag interface to the time of passing the slag-molten metal interface, or from the time of passing the molten metal-slag interface to the time of passing the slag-atmosphere interface, the moving time of the electrode is measured. The moving distance of the electrode may be obtained by calculation from the moving speed.
That is, as a fifth slag layer thickness measuring method, in the above-described first, second, third, or fourth slag layer thickness measuring method, the moving speed of the upward movement or the downward movement of the electrode is constant. And, when using a method of moving the electrode upward from the molten metal layer to the atmosphere layer, the moving time of the electrode from the molten metal-slag interface passage time to the slag-air interface passage time, Measure, when using the method of moving the electrode down from the atmospheric layer to the molten metal layer, the air-moving time of the electrode from the air-slag interface passing time to the slag-molten metal interface passing time, Instead of measuring and measuring the moving distance of the electrode, a slag layer thickness measurement is obtained by calculating the moving distance of the electrode from the moving speed and the moving time of the electrode. Law exists.

According to this method, it is not necessary to directly measure the moving distance of the electrode, and the measuring method is simplified.

Next, the slag layer thickness measuring apparatus of the present invention will be described. First, the first slag layer thickness measuring device
An electrode, a container containing a molten metal in which a slag layer floats on the surface of the molten metal layer, and a container having conductivity, and transferring the electrode from the molten metal layer to the atmosphere layer occupying the upper layer of the slag layer through the slag layer. An electrode moving means for moving upward or moving downward from the atmospheric layer through the slag layer to the molten metal layer, and a DC power supply Vcc having the electrode side as a cathode between the electrode and the container. A resistor Rx connected in series with this power supply is inserted, and the values of the DC power supply Vcc and the resistance Rx are determined by using the potential of the container as a reference potential when the electrode is immersed in the slag layer. A measuring circuit formed by setting the potential of the electrode to be higher than the reference potential, a potential measuring means for measuring the potential of the electrode with respect to the reference potential, and the potential measuring means detecting From the time when the reference potential changes to the high potential, from the time when the high potential changes to a low potential lower than the reference potential, or from the time when the low potential changes to the high potential, the high potential And an electrode moving distance measuring means for measuring the moving distance of the electrode from the time when the voltage changes to the reference potential.

In the first slag layer thickness measuring device, when the electrode is moved upward from the molten metal layer through the slag layer to the atmosphere layer occupying the upper layer of the slag layer, the potential measuring means contains the molten metal. As the time at which the electrode-vessel characteristic between the vessel and the electrode passes through the molten metal-slag interface at which transition from conductivity to power generation occurs, the time at which the potential of the electrode changes from the reference potential to a higher potential higher than the reference potential. At the same time, the time when the potential of the electrode changes from the high potential to the low potential lower than the reference potential is detected as the time of passing through the slag-atmosphere interface where the power generation changes to the insulating property. Then, the electrode moving distance measuring means detects the slag from the time of passage through the molten metal-slag interface.
Find the moving distance of the electrode up to the time of passing through the air interface,
The thickness of the slag layer. When the electrode is moved downward from the atmospheric layer to the molten metal layer through the slag layer, the potential measuring means determines the characteristics of the electrode-container between the container containing the molten metal and the electrode, and indicates that the electrode is in the atmospheric layer. As the air-slag interface passes through the air-slag interface, where the electrode enters the slag layer functioning as an electrolyte and shifts to power generation due to the insulating properties due to the interposition of the atmosphere when the electrode is at a potential lower than the reference potential, Along with detecting the point of time when the electrode potential changes to a high potential, the electrode-vessel characteristic changes from the power generation property to the slag-molten metal interface point where the electrode enters the molten metal layer and transitions to electrical conductivity. , The point in time when the potential changes from the high potential to the reference potential is detected. Then, the electrode moving distance measuring means obtains the moving distance of the electrode from the time of passing through the air-slag interface to the time of passing through the slag-molten metal interface, and sets this as the thickness of the slag layer.

That is, this apparatus is an apparatus for determining the thickness of a slag layer based on the third slag layer thickness measuring method or the fourth slag layer thickness measuring method described above. The effect is similar to that of the third slag layer thickness measuring method or the fourth slag layer thickness measuring method described above, and therefore the description is omitted.

In the first slag layer thickness measuring device,
Although the moving distance of the electrode is obtained by the electrode moving distance measuring means for directly measuring, a second slag layer thickness measuring device obtained by calculation from the moving speed and the moving time of the electrode is also conceivable. This second slag layer thickness measuring apparatus comprises: an electrode; a conductive container containing a molten metal in which the slag layer floats on the surface of the molten metal layer; Electrode moving means for moving upward from the metal layer through the slag layer to the atmospheric layer occupying the upper layer of the slag layer, or moving downward from the atmospheric layer through the slag layer to the molten metal layer, DC power supply V between the electrode and the container, the electrode side being a cathode
cc and a resistor Rx connected in series with the power source, and the values of the DC power source Vcc and the resistor Rx are set to a reference potential when the electrode is immersed in the slag layer. A measuring circuit formed by setting the potential of the electrode to be higher than the reference potential; a potential measuring means for measuring the potential of the electrode with respect to the reference potential; From the time when the reference potential changes to the high potential, from the time when the high potential changes to a low potential lower than the reference potential, or from the time when the low potential changes to the high potential, The electrode moving time measuring means for measuring the moving time of the electrode, from the time when the potential changes to the reference potential, and the moving speed and the moving time of the electrode, and the electrode And an electrode moving distance calculating means for calculating a moving distance of the slag layer.

The second slag layer thickness measuring device calculates the moving distance of the electrode from the moving speed and the moving time of the electrode, and thus has the same effect as the fifth slag layer thickness measuring method. Have. Also, except that the moving distance of the electrode is obtained by calculation from the moving speed and the moving time of the electrode,
The configuration is exactly the same as that of the above-mentioned first slag layer thickness measuring device, and the operation and effect are exactly the same as those of the above-mentioned first slag layer thickness measuring device.

In the above-mentioned second slag layer thickness measuring apparatus, a third slag layer thickness measuring apparatus which measures the moving speed of the electrode by using two electrodes is conceivable. This third slag layer thickness measuring device is the same as the above-mentioned second slag layer thickness measuring device, except that one electrode is added in addition to the electrodes, and the lower ends of these two electrodes are connected to the same. By disposing the electrodes at a fixed distance in the moving direction and simultaneously moving two of these electrodes, the time lag of the potential detected by each of the two electrodes with respect to the container is measured, and the time lag is measured. A slag layer thickness measuring device provided with a moving speed detecting means for obtaining the moving speed from the fixed distance.

FIG. 6A is an explanatory diagram of the principle of speed detection by the moving speed detecting means used in the third slag layer thickness measuring device. In FIG. 6A, the lower end of the electrode 22 is located above the lower end of the electrode 21 by a distance D in the upward direction, which is the moving direction.
And the electrodes 21 and 22 are connected to the I and the second inputs of the measuring device 23, respectively. Further, the method of measuring the potential of the electrodes 21 and 22 with respect to the container 1 in the measuring device 23 uses the same method as the above-described method of measuring the potential of the electrodes. Therefore, the electrodes 21, 2
When two electrodes 2 are simultaneously moved upward from the molten metal layer 2 through the slag layer 3 to the atmosphere layer 4, the potentials of the electrodes 21 and 22 become as shown in FIG. And
It will be shifted by T. Then, the electrodes 21 and 22
Is obtained by S = D / T. According to this slag layer thickness measuring device, it is not necessary to determine the moving speed of the electrode in advance.

Although the first to third slag layer thickness measuring devices described above are directed to molten metal, molten steel can be used as the molten metal.

In the slag layer thickness measuring apparatus using molten steel as the molten metal, the material of the electrodes used for the slag layer is Mo, C
It is recommended to use an iron alloy containing at least one of o, Cr and Mn. In the slag layer thickness measuring device described above, the molten metal in the container is at a high temperature, and the electrodes immersed in the molten metal will melt over time. Therefore, it is desirable to make the time until melting as long as possible,
In this respect, the above alloy is difficult to melt and is excellent as a material of the electrode.

In each slag layer thickness measuring device described above, when measuring the slag layer thickness, if the oxygen concentration needs to be measured, the electrode may be used in combination with the molten steel electrode of the oxygen probe. good. By doing this,
At the same time, the measurement of the thickness of the slag layer and the measurement of the oxygen concentration can be performed, and the electrodes can be used together, so that the cost of the measuring device can be reduced.

In the above slag layer thickness measuring apparatus, the lower tip position of the electrode used in combination with the molten steel electrode of the oxygen probe and the zirconia electrode of the oxygen probe are aligned, and a portion other than both tip portions is quartz tube. It may be used by covering with a protection pipe such as. By doing so, it is possible to prevent slag from being attached to both the electrode and the zirconia electrode of the oxygen probe, and simultaneously measure the thickness of the slag layer and measure the oxygen concentration. In addition, since the electrodes can be used together, the cost of the measuring device can be reduced.

In each of the above-described slag layer thickness measuring devices, an electrode may be attached to a molten steel temperature measuring probe for use. By doing so, the measurement of the thickness of the slag layer and the measurement of the molten steel temperature can be performed at the same time, and the electrodes can be used together, so that the cost of the measuring device can be reduced.

In the case of a container containing molten metal, such as a converter, a vacuum tank provided with a dip tube at the bottom is disposed above the slag floating on the molten metal, and the dip tube is dipped in the molten metal. And take the molten metal into the vacuum chamber,
By adding a and the like to aggregate the particles of the slag component in the molten metal, the slag component in the molten metal is easily removed. In this case, it is necessary to water-cool the immersion tube, and if this cooling water comes into contact with the molten metal, an explosion may occur. Therefore, it is necessary to measure the surface level position of the molten metal layer. The above description relates to a slag layer thickness measuring method or its apparatus,
The principle used here can be used not only for measuring the slag layer thickness, but also for measuring the surface level position of the molten metal layer. A method for measuring a surface level position of the layer, that is, a method of measuring a distance from a fixed point located at a predetermined fixed distance from the container to the surface of the molten metal layer above the opening of the container containing the molten metal will be described.

In this method, the first method for measuring the thickness of the slag layer and the position of the molten metal layer surface level is that the molten metal in which the slag layer floats on the surface of the molten metal layer is provided above the opening of the conductive container. In a method for measuring the distance from a fixed point located at a predetermined constant distance from the container to the surface of the molten metal layer, and the thickness of the slag layer, wherein the slag from the molten metal layer The electrode is moved upward to the fixed point in the atmospheric layer occupying the upper layer of the slag layer through the layer, and the electrode-container characteristic, which is the electric characteristic between the container and the electrode, is monitored. -The inter-container characteristics, the conductivity of the molten metal layer when the electrode is immersed in the molten metal layer, from the conductivity of the molten metal layer, the electrode moves to the slag layer, the presence of the slag layer that functions as an electrolyte Departure by Molten metal is a time to move to sex -
A slag which is a point in time when the electrode escapes from the slag layer to the atmosphere layer when the electrode passes through the slag interface and the electrode-vessel characteristic shifts from the power generation property to the insulation property due to the interposition of the atmosphere layer. Along with detecting the air interface passing time, and from the molten metal-slag interface passing time to the slag-air interface passing time, the moving distance of the electrode was measured, and the thickness of the slag layer, From the time of passing the molten metal-slag interface to the fixed point, the moving distance of the electrode was measured, and the slag layer thickness and the molten metal layer surface level as the distance from the fixed point to the surface of the molten metal layer This is a position measurement method.

FIG. 7 is an explanatory diagram showing the measurement principle of the above method. In the above method, in FIG. 7, a position which is separated from the container 1 by a predetermined fixed distance above the opening of the container 1 which holds the molten metal in which the slag layer floats on the surface of the molten metal layer and has conductivity. The electrode 5 is moved upward from the molten metal layer through the slag layer to a fixed point 9 in the atmospheric layer occupying the upper layer of the slag layer, and the electrode 5 is moved between the electrode 5 and the container 1 during this time. The thickness 6 of the slag layer and the distance 10 from the fixed point 9 to the surface of the molten metal layer 2 are measured by utilizing the change in the characteristic between the electrode and the container, which is a characteristic characteristic. In the above method, the measuring method of the thickness 6 of the slag layer is:
It is exactly the same as the first slag layer thickness measuring method. Also,
The method of detecting the point 7 of passing through the molten metal-slag interface used for measuring the distance 10 from the fixed point 9 to the surface of the molten metal layer 2 is exactly the same as the first slag layer thickness measuring method. The distance 10 from the fixed point 9 to the surface of the molten metal layer 2 can be obtained by measuring the distance that the electrode 5 has moved from the interface passing point 7 to the fixed point 9.

In the above method, the electrode 5 is moved upward, but the electrode may be moved downward. Further, as described above, in FIG. 7, the measurement of the surface level position of the molten metal layer means that the distance 10 from the fixed point 9 to the surface of the molten metal layer 2 is measured. Determining the distance from the fixed point to the surface of the molten metal layer here is from the time of passing the molten metal-slag interface to the fixed point, or
From the fixed point to the point of passing through the slag-molten metal interface,
It can be performed by measuring the distance or time that the electrode 5 has moved, and the detection of the time of passage through the molten metal-slag interface or the time of passage through the slag-molten metal interface is used in each of the slag layer thickness measurement methods described above. Detection method can be used as is. Therefore, the second, third, fourth, or fifth slag layer thickness and molten metal layer surface level position measurement method, or the first or second slag layer thickness and molten metal layer surface level position measurement By applying each of the above-described slag layer thickness measuring methods or each of the above-described slag layer thickness measuring apparatuses as the apparatus, the following methods and apparatuses can be considered.

The second method for measuring the thickness of the slag layer and the position of the molten metal layer at the surface level is characterized in that the molten metal in which the slag layer floats on the surface of the molten metal layer is provided above the opening of the conductive container. A method for measuring the distance from a fixed point located at a predetermined distance away from the surface of the molten metal layer, and the thickness of the slag layer, wherein the air layer occupies the upper layer of the slag layer. By moving the electrode down from the fixed point through the slag layer to the molten metal layer,
An electrode-container characteristic that is an electrical characteristic between the container containing the molten metal and having conductivity and the electrode is monitored, and the electrode-container characteristic is such that the electrode is in the atmospheric layer. At the time when the electrode is immersed in the slag layer and shifts to power generation by the interposition of the slag layer functioning as an electrolyte from the insulating property due to the interposition of the atmosphere, the air passes through the air-slag interface, and the electrode is Moving from the slag layer to the molten metal layer, the electrode-container characteristic is detected as a point in time at which the slag-molten metal interface passes, which is a point in time when the power generation property shifts to conductivity due to the interposition of the molten metal layer. And, from the fixed point to the slag-molten metal interface passing time, by measuring the moving distance the electrode has moved, and as the distance from the fixed point to the surface of the molten metal layer,
From the time of passing through the air-slag interface to the time of passing through the slag-molten metal interface, the movement distance of the electrode was measured, and the slag layer thickness and the molten metal layer surface level position as the thickness of the slag layer were measured. It is a measuring method.

The third method for measuring the thickness of the slag layer and the surface level of the molten metal layer is a method for measuring the thickness of the slag layer and the surface level of the molten metal layer according to the first method. A DC power supply Vcc having a cathode on the electrode side;
A resistor Rx connected in series with this power source is inserted, and the values of the DC power source Vcc and the resistor Rx are set to the potential of the container as a reference potential when the electrode is immersed in the slag layer. The potential of the electrode is set to be a high potential higher than the reference potential, and the electrode is moved upward from the molten metal layer to the atmospheric layer to measure the potential of the electrode with respect to the reference potential. , The molten metal
As the slag interface passing time, the potential of the electrode is changed from the reference potential to the high potential, and as the slag-air interface passing time, the electrode potential is higher than the reference potential from the high potential. This is a method of measuring the thickness of the slag layer and the position of the molten metal layer surface level by detecting the point at which the potential changes to a low potential.

The fourth method for measuring the thickness of the slag layer and the surface level of the molten metal layer is the same as the method of measuring the thickness of the slag layer and the surface level of the molten metal layer. A DC power supply Vcc with the electrode side as a cathode,
A resistor Rx connected in series with this power source is inserted, and the values of the DC power source Vcc and the resistor Rx are set to the potential of the container as a reference potential when the electrode is immersed in the slag layer. The potential of the electrode is set so as to be higher than the reference potential, and the electrode is moved downward from the atmospheric layer to the molten metal layer to measure the potential of the electrode with respect to the reference potential. The time at which the potential of the electrode changes from a low potential lower than the reference potential to the high potential as the air-slag interface passing time,
Further, the method is a method for measuring a slag layer thickness and a molten metal layer surface level position by detecting a time point at which the potential of the electrode changes from the high potential to the reference potential as the slag-molten metal interface passing time. .

The fifth method for measuring the slag layer thickness and the molten metal layer surface level position is the method according to the first, second, third or fourth method for measuring the slag layer thickness and the molten metal layer surface level position. When a method of moving the electrode upward and downward from the molten metal layer to the atmospheric layer while keeping the moving speed of the upward movement or the downward movement of the electrode constant is used, for calculating the thickness of the slag layer, From the time of passing the metal-slag interface to the time of passing the slag-air interface,
Measuring the moving time of the electrode, for calculating the distance from the fixed point to the surface of the molten metal layer, measuring the moving time of the electrode from the time of passing the molten metal-slag interface to the fixed point, When using the method of moving downward from the atmospheric layer to the molten metal layer, for calculating the distance from the fixed point to the surface of the molten metal layer, from the fixed point to the slag-molten metal interface passing time, Measuring the moving time of the electrode, for calculating the thickness of the slag layer, measuring the moving time of the electrode from the time of passing through the air-slag interface to the time of passing the slag-molten metal interface, Instead of measuring each moving distance, from the moving speed of the electrode and each moving time,
A method for measuring a slag layer thickness and a molten metal layer surface level position obtained by calculating each of the moving distances of the electrode by calculation.

The first slag layer thickness and molten metal layer surface level position measuring device comprises: an electrode; a conductive container containing a molten metal in which the slag layer floats on the surface of the molten metal layer; Moving upward from the molten metal layer to a fixed point located at a predetermined fixed distance from the container above the opening of the container in the atmospheric layer occupying the upper layer of the slag layer through the slag layer. Or, from the fixed point in the atmospheric layer, through the slag layer to the molten metal layer, electrode moving means to move down, between the electrode and the container, the electrode side as a cathode DC power supply V
cc and a resistor Rx connected in series with the power source, and the values of the DC power source Vcc and the resistor Rx are set to a reference potential when the electrode is immersed in the slag layer. A measuring circuit formed by setting the potential of the electrode to be higher than the reference potential; a potential measuring means for measuring the potential of the electrode with respect to the reference potential; and a thickness of the slag layer. For measurement, detected by the potential measuring means, from the time when the reference potential changes to the high potential, from the time when the high potential changes to a low potential lower than the reference potential, or from the low potential From the time when the potential changes to the high potential, to the time when the potential changes from the high potential to the reference potential, an electrode moving distance measuring means for slag layer thickness measurement for measuring the moving distance of the electrode, from the fixed point For measuring the distance to the surface of the molten metal layer, from the point of time when the potential measurement means changes from the reference potential to the high potential to the fixed point, or from the fixed point, from the high potential to the reference potential. And a slag layer thickness and molten metal layer surface level position measuring device, comprising: a molten metal layer surface level position measuring electrode moving distance measuring means for measuring a moving distance of the electrode up to the time when the electrode changes. .

The second slag layer thickness and molten metal layer surface level position measuring device comprises: an electrode; a container containing a molten metal in which the slag layer floats on the surface of the molten metal layer; The electrode is moved at a constant speed, from the molten metal layer, through the slag layer, in the atmospheric layer occupying the upper layer of the slag layer, above the opening of the container, at a predetermined distance from the container. Move upward to a fixed point located away from, or from the fixed point in the atmospheric layer,
An electrode moving means for moving down through the slag layer to the molten metal layer, a DC power supply Vcc having the electrode side as a cathode between the electrode and the container, and a resistor Rx connected in series with the power supply And the DC power supply Vcc
And the value of the resistor Rx are set such that when the electrode is immersed in the slag layer, the potential of the container is set as a reference potential and the potential of the electrode is set to a potential higher than the reference potential. The formed measuring circuit, a potential measuring means for measuring the potential of the electrode with respect to the reference potential, and a change from the reference potential to the high potential detected by the potential measuring means for measuring the thickness of the slag layer. From the moment
The electrode from the high potential to the low potential lower than the reference potential, or from the low potential to the high potential, to the high potential to the reference potential, A slag layer thickness measuring electrode moving time measuring means for measuring the moving time of the slag layer, and for measuring the distance from the fixed point to the surface of the molten metal layer, the potential measuring means detected, from the reference potential to the high potential From the point of change to the fixed point or from the fixed point to the point of change from the high potential to the reference potential. Means, and a slag layer thickness calculating means for calculating a moving distance of the electrode by calculation from the moving speed of the electrode and each of the moving times. And a molten metal layer surface level position measuring device.

According to the slag layer thickness and molten metal layer surface level position measuring method or the slag layer thickness and molten metal layer surface level position measuring device described above, the slag layer thickness measuring method or the slag layer described above is used. By using the principle used for the thickness measuring device, it is possible to measure not only the thickness of the slag layer but also the surface level position of the slag layer.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. Although the present invention is directed to molten metal, the slag layer thickness measuring apparatus according to the first embodiment of the present invention uses molten steel as molten metal. FIG. 8 is an explanatory diagram showing the configuration of the slag layer thickness measuring device according to the first embodiment. In FIG. 8, 31 is a converter, 32 is a molten steel layer, 33 is a slag layer, 34 is an atmospheric layer,
5 is an electrode, 36 is a probe, 37 is a lance, 38 is a lance moving device, 39 is an encoder, 40a is a measuring device, 4
1 is a DC power supply Vcc, 42 is a resistor Rx, 43 is an electrode potential measurement circuit (analog circuit), 44 is a lance movement control circuit,
5 is an encoder pulse count circuit, 47 is a microcomputer, and 48 is a display. In the first embodiment, a converter is used as a container for storing molten steel, but a ladle may be used.

In FIG. 8, an electrode 35 is a probe 36
The electrode 35 is moved by vertically moving the lance 37 holding the probe 36 by the lance moving device 38 in the vertical direction. The lance moving device 38 includes a motor such as a pulse motor and a servo motor that can perform positioning control, a device that converts the rotational motion of the rack and pinion into a linear motion, and the like. Lance moving device 38 having such a configuration
Instead, a feed screw mechanism as shown in FIG. 12 may be used. In FIG. 12, a paper probe is used as a substitute for the lance, and the probe is rotated to move up and down.

FIG. 9 shows the electrode 35 and the probe 3 shown in FIG.
6 and the structure of the joining portion of the lance 37. 9, the electrode 35 is connected to a contact contact 51 of a probe 36, and a ring contact 52 in contact with the contact contact 51 is connected to an electrode potential measuring circuit (analog circuit) 43. The probe 36 can withstand the molten high-temperature molten steel only for a short time necessary for the measurement, and needs to be replaced every time the measurement is performed. This structure is employed. In FIG. 8, the converter 3
1 is generally formed by stacking refractory bricks inside a metal container, and has no conductivity by the converter 31 alone, but by storing molten steel in the converter 31, When the metal adheres to the inner surface, the space between the inner surface of the converter 31 and the ground becomes conductive. That is, it is equivalent to the converter 31 being grounded to the ground. Further, between the ground and the electrode 35, a DC power source Vcc11 having the electrode 35 side as a cathode and a resistor Rx12 connected in series with the DC power source 11 are connected. Here, the values of the DC power supply 11 and the resistance Rx12 are set such that, when the electrode 35 is immersed in the slag layer 33, the potential of the electrode 5 with respect to the converter 31 having the same potential as the ground becomes a positive potential. ing.
Specifically, as described above, the resistance Rx12 is smaller than the internal resistance in the chemical battery characteristics indicated by the slag layer 33.
The resistance is set to an extremely large value. For example, the internal resistance in the battery characteristics indicated by the slag layer 33 is about several tens to several hundreds of ohms, while the resistance Rx12 is set in the order of several hundreds of kilohms. As a result, as described above, the potential between the electrode 35 and the ground becomes substantially equal to the electromotive force in the chemical cell characteristics indicated by the slag layer 33. Since this electromotive force is positive with respect to the ground, the potential of the electrode 35 becomes a positive potential. The electrode potential measuring circuit (analog circuit) 43 is provided with an electrode 35 with the potential of the converter 31 being the ground potential as a reference potential.
This is a circuit for measuring the potential of the circuit. The encoder 39 is interlocked with the lance moving device 38, and generates a pulse for measuring the moving distance when the lance 37 moves up and down, and the encoder pulse counting circuit 45 counts this pulse. The movement distance of 37 is obtained.
Instead of using the encoder 39, the lance is provided with an uneven or black-and-white striped scale in the direction of movement on the side surface of the lance. Detect pattern changes,
A method of counting and measuring the moving distance of the lance is also conceivable.

In the measuring apparatus shown in FIG.
Is moved downward from the atmospheric layer 34 through the slag layer 33 to the molten steel layer 32, or conversely, is moved upward from the molten steel layer 32 through the slag layer 33 to the atmospheric layer 34, and the electrode 35 and the container are interposed therebetween. The slag layer 33 is formed by utilizing the change in the electrode-vessel characteristic which is an electrical characteristic between the converter 31 and the slag layer 33.
In the first embodiment, the thickness of the slag layer 33 is measured by moving upward from the molten steel layer 32 through the slag layer 33 to the atmosphere layer 34. In this case, the change in the potential of the electrode 35 with the potential of the converter 31 having the same potential as the ground as the reference potential is as shown in FIG. 5 described above. In FIG. 5, when the measurement is started at the point of time Ta and the electrode 35 is located on the molten steel layer 32 (a), Va is 0 (V). At the time Tb when the electrode 35 shifts from the molten steel layer 32 to the slag layer 33, that is, at the time of passing through the molten steel-slag interface, Vb becomes a positive potential at Vb. Further, at time Tc when the electrode 35 shifts from the slag layer 33 to the atmosphere layer 34, that is, at the time of passing through the slag-atmosphere interface, Vc becomes -Vcc (V) and becomes a negative potential. Therefore, the distance that the electrode 35 has moved, that is, the distance that the lance 37 has moved, is counted by the encoder pulse counting circuit 45, and the potential of the electrode 35 becomes 0.
The time when the potential changes from (V) to the positive potential and the time when the potential changes from the positive potential to the negative potential are determined by an electrode potential measuring circuit.
(Analog circuit) 43, and the output signals of the encoder pulse count circuit 45 and the electrode potential measurement circuit (analog circuit) 43 during this period are input to the microcomputer 47, and the thickness of the slag layer is determined. Is displayed on the display 48.

In the above-described measuring apparatus, the moving distance of the electrode 35 is directly obtained by using the pulse output from the encoder 39. However, there is also a method of obtaining the moving distance and the moving time of the electrode by calculation. In this method, the encoder 39 and the encoder pulse count circuit 45 are removed from FIG. 8, the moving speed of the electrode 35 is set to a predetermined constant speed, and the electrode potential measuring circuit (analog circuit) 43 determines the time when the molten steel-slag interface has passed. The point of time of passage through the slag-atmosphere interface is detected, and individual signals are input to the microcomputer 47. The microcomputer 47 is connected to the electrode 3
5 is calculated, and the moving distance of the electrode 35 is calculated from the moving time and the moving speed of the electrode 35 to obtain the thickness of the slag layer. In this method, the moving speed of the electrode is determined in advance, and the thickness of the slag layer is obtained by using the moving speed for the calculation.However, the moving speed of the electrode is not determined in advance, and the moving speed of the electrode is described above. As described above, the measurement may be performed using two electrodes as shown in FIG.

Also in the case of the method of obtaining the moving distance from the moving time and the moving speed of the electrode 35, the change in the potential of the electrode 35 with the reference potential of the converter 31 having the same potential as the ground is
The result is as shown in FIG. In a slag layer thickness measuring apparatus using this method, a change in the potential can be displayed on a display provided in the measuring apparatus, and a calculation result of the slag layer thickness can be displayed. FIG.
It shows a display example in the slag layer thickness measuring device in this case. Also, FIGS. 11 (a), (b), (c),
(D) shows an example of a change in the potential of the electrode 35 in such a case.

In the above-described measuring device, the electrode 35 is moved upward from the molten steel layer 32 through the slag layer 33 to the atmosphere layer 34.
The thickness of the slag layer 33 can be similarly determined even when the slag layer 33 is moved down to the molten steel layer 32 through the slag layer 3. In the above-described measuring device, the electrode 35 is moved up and down in the vertical direction, but may be moved obliquely with respect to the slag layer 33. In this case, the thickness of the slag layer can be obtained by calculation from the tilted angle and the moving distance of the electrode.

According to the above measuring apparatus, as can be seen from FIG. 11, the change in the potential of the electrode 35 is 0 (V), which is the reference potential, and the positive potential, which is higher than this reference potential. Since this is a change to any one of the negative potentials, which is a low potential lower than the reference potential, it is possible to accurately detect these changes. Since it can be obtained accurately, the thickness of the slag layer 33 can be accurately known. Further, even if the impedance between the electrode 35 and the container 31 changes due to the contact resistance of a connector or the like connected to the electrode 35, the change in the potential of the electrode 35 is the same as the reference potential,
Since it is still a change to either a high potential higher than the reference potential or a low potential lower than the reference potential, the measurement method using the above-described measuring device is performed between the electrode 35 and the container 31. It can be said that this is a measurement method that is hardly affected by the change in impedance.

In the first embodiment, as described above,
Although the description is directed to molten steel, the contents described above can be generally applied to the case of molten metal.

In the slag layer thickness measuring device for measuring the slag layer thickness of molten steel, it is recommended that the material of the electrode be an iron alloy containing at least one of Mo, Co, Cr and Mn. Is done. In the slag layer thickness measuring device described above, the molten metal in the container is at a high temperature, and the electrodes immersed in the molten metal will melt over time. Therefore, it is desirable to make the time until melting as long as possible. In this regard, the above alloy is difficult to melt and is excellent as a material of the electrode.

In the slag layer thickness measuring device described above,
When measuring the thickness of the slag layer, the electrode used for measuring the oxygen concentration may be used in combination with the molten steel electrode of the oxygen probe. By doing so, the measurement of the thickness of the slag layer and the measurement of the oxygen concentration can be performed at the same time, and the electrodes can be used together, so that the cost of the measuring device can be reduced.

In the slag layer thickness measuring apparatus described above, the lower tip positions of the electrode used in combination with the molten steel electrode of the oxygen probe and the zirconia electrode of the oxygen probe are aligned, and portions other than both tip portions are quartz tube. It may be used by covering with a protection pipe such as. By doing so, it is possible to prevent slag from being attached to both the electrode and the zirconia electrode of the oxygen probe, and simultaneously measure the thickness of the slag layer and measure the oxygen concentration. In addition, since the electrodes can be used together, the cost of the measuring device can be reduced.

In the slag layer thickness measuring apparatus described above, the electrode may be used by attaching it to a molten steel temperature measuring probe. By doing so, the measurement of the thickness of the slag layer and the measurement of the molten steel temperature can be performed at the same time, and the electrodes can be used together, so that the cost of the measuring device can be reduced.

As described above, in a vessel containing molten steel, such as a converter, a vacuum tank provided with a dip tube at the bottom is disposed above the slag floating on the molten steel, and the dip tube is dipped in the molten steel. Then, the molten steel is taken into the vacuum chamber, Ca and the like are added to agglomerate the particles of the slag component in the molten steel, so that the slag component in the molten steel is easily removed. In this case, it is necessary to cool the immersion tube with water, and if this cooling water and molten steel come into contact with each other, an explosion may occur. Therefore, it is necessary to measure the surface level position of the molten steel layer. Therefore, next, along with the measurement of the slag layer thickness, the surface level position of the molten steel layer, that is, above the opening of the container containing the molten metal, from the fixed point located at a predetermined fixed distance from the container, Second Embodiment A slag layer thickness and a molten steel layer surface level position measuring apparatus according to a second embodiment of the present invention for measuring a distance to a surface will be described. The change in the distance from the fixed point to the surface of the molten steel layer, measured with this device,
The position of the vacuum chamber can be controlled by reflecting the positional relationship between the fixed point and the vacuum chamber.

FIG. 15 is an explanatory view showing a configuration of a slag layer thickness and molten steel layer surface level position measuring apparatus according to a second embodiment of the present invention. In FIG. 15, the same numbers as those in FIG.
The contents are the same as those in FIG. 8 is different from FIG. 8 in that a vacuum chamber 24 provided with a dip tube 25 at the bottom is disposed above the converter 31 and a fixed point detection mark 28 for detecting a state where the electrode 35 is located at a fixed point 49 is provided. A light source 27 and a sensor 29 for detecting the fixed point detection mark 28 are provided on a side surface of the lance 37, a fixed point detection circuit 46 is provided, and an output of the sensor 29 is input to the fixed point detection circuit 46. That is, the output of the fixed point detection circuit 46 is input to the microcomputer 47. Also in the second embodiment, similarly to the first embodiment, the molten steel layer 32 is moved upward from the molten steel layer 32 to the atmosphere layer 34 through the slag layer 33, and the thickness of the slag layer and the distance from the fixed point to the surface of the molten steel layer are measured. Measure the distance.

In this case, the method of measuring the thickness of the slag layer is as follows.
This is exactly the same as the first embodiment. In addition, the distance from the fixed point to the surface of the molten steel layer is determined at the time when the electrode 35 shifts from the molten steel layer 32 to the slag layer 33, that is, when the electrode 35 passes from the molten steel-slag interface to the fixed point, Lance 3
7 may be measured. The time of passing through the molten steel-slag interface is the time when the potential of the electrode 35 changes from the reference potential to the high potential, and the time when the fixed point is reached,
These detection signals are input to the microcomputer 47 via the fixed point detection circuit 46 since the sensor 29 has detected the fixed point detection mark 28,
Similarly to the first embodiment, the microcomputer 47 calculates the thickness of the slag layer and the distance from the fixed point to the surface of the molten steel layer, and the condition is displayed on the display 48.

In the slag layer thickness and molten steel layer surface level position measuring apparatus according to the second embodiment, the measurement may be performed by moving the electrode down and moving as in the first embodiment. Further, the moving distance of the electrode 35 may be obtained by calculation from the moving speed and the moving time of the electrode. For this purpose, the moving speed of the electrodes may be measured using two electrodes as shown in FIG. Further, the electrodes may be moved obliquely with respect to the slag layer. In addition, a ladle may be used as a container for storing molten steel. In addition, not only molten steel but also general molten metal can be used.

According to the slag layer thickness and molten steel layer surface level position measuring device of the second embodiment described above, by using the principle used in the above-described slag layer thickness measuring device,
In addition to measuring the slag layer thickness, the surface level position of the slag layer can be measured.

In both the first embodiment and the second embodiment described above, the DC power supply 11 uses the electrode 35 as a cathode, but if the electrode 35 is used as an anode, in principle,
It can be measured. That is, in FIGS. 8 and 15, V
Even if the polarity of cc is reversed, the electrical characteristics of the slag layer
It is possible to measure the thickness of the slag layer and to measure the surface level position of the slag layer using the difference between the lower layer of molten steel and the atmosphere of the upper layer.

[0061]

According to the method for measuring the thickness of a slag layer according to the first or second aspect of the present invention, the electric conductivity and the power generation are the changes in the electrode-container characteristics which are the electric characteristics between the electrode and the container. The measurement is performed by utilizing the change between the properties of the insulating or insulating properties. Since this change is not a change between homogeneous things such as a change in impedance, it is a change between different things, so it is possible to capture the change clearly,
A slag layer thickness measuring method capable of accurately measuring the thickness of a slag layer can be provided. Further, since the electrode itself is not expensive in terms of cost, it may be replaced every time the measurement is performed, and it is not necessary to prevent the electrode from being damaged. A slag layer thickness measuring method can be provided.

According to the slag layer thickness measuring method according to the third or fourth aspect, the change in the potential of the electrode includes a reference potential, a high potential higher than the reference potential, and a low potential lower than the reference potential. It is a change in the potential, and the change can be captured digitally, so that the change can be detected accurately, and the moving distance of the electrode can be accurately obtained based on these detections. Since it is possible, it is possible to provide a slag layer thickness measuring method capable of accurately knowing the thickness of the slag layer. Also, even if the impedance between the electrode and the container changes due to the contact resistance of a connector or the like on the way from the electrode to the circuit for measuring this potential, the change in the potential of the electrode is determined by the reference potential and the reference potential. Is still a change to either a high potential, which is high, or a low potential, which is lower than this reference potential. A difficult slag layer thickness measurement method can be provided.

According to the slag layer thickness measuring method according to the fifth aspect, it is not necessary to directly measure the moving distance of the electrode, and a slag layer thickness measuring method that can simplify the measuring method can be provided.

According to the slag layer thickness measuring apparatus of the sixth aspect, the change in the potential of the electrode is one of the reference potential, the high potential higher than the reference potential, and the low potential lower than the reference potential. Since the change can be captured digitally, the change can be detected accurately, and based on these detections, the moving distance of the electrode can be accurately obtained. A slag layer thickness measuring device capable of accurately knowing the layer thickness can be provided.
Also, even if the impedance between the electrode and the container changes due to the contact resistance of the connector or the like connected to the electrode,
Since the change in the potential of the electrode is still a change to one of the reference potential, a high potential higher than the reference potential, and a low potential lower than the reference potential, according to this measurement method, In addition, it is possible to provide a slag layer thickness measuring device that is hardly affected by a change in impedance between the electrode and the container.

According to the slag layer thickness measuring apparatus of the seventh aspect, the following effect is obtained in addition to the effect of the slag layer thickness measuring apparatus of the sixth aspect. That is, according to the slag layer thickness measuring apparatus, it is not necessary to directly measure the moving distance of the electrode, and therefore, it is possible to provide a slag layer thickness measuring apparatus that can simplify the measuring method.

According to the slag layer thickness measuring apparatus according to the eighth aspect, it is possible to provide a slag layer thickness measuring apparatus which does not need to determine the moving speed of the electrode in advance.

According to the slag layer thickness measuring device of the ninth aspect, a slag layer thickness measuring device for molten steel can be provided.

According to the slag layer thickness measuring device of the tenth aspect, it is possible to provide a slag layer thickness measuring device that is hard to melt the electrodes when measuring the slag layer thickness.

According to the slag layer thickness measuring apparatus according to the eleventh aspect, the thickness of the slag layer and the oxygen concentration can be measured at the same time, and the electrodes can be used together. Reduction can be achieved.

According to the slag layer thickness measuring apparatus of the twelfth aspect, it is possible to prevent slag from adhering to both the electrode and the zirconia electrode of the oxygen probe, and at the same time, to reduce the thickness of the slag layer. And the measurement of oxygen concentration can be performed, and the electrodes can be used together, so that the cost of the measuring device can be reduced.

According to the slag layer thickness measuring device according to the thirteenth aspect, the thickness of the slag layer and the temperature of the molten steel can be measured at the same time, and the electrodes can be used together. Reduction can be achieved.

The method for measuring the slag layer thickness and the molten metal layer surface level position according to any one of claims 14 to 18, or the slag layer thickness and the molten metal layer surface level position according to claims 19 and 20. According to the measuring device, by using the slag layer thickness measuring method or the principle used in the slag layer thickness measuring device, not only the measurement of the slag layer thickness, but also the surface level position of the molten metal layer can do.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the principle of a first slag layer thickness measuring method of the present invention.

FIG. 2 is an explanatory view showing the principle of a third slag layer thickness measuring method of the present invention.

FIG. 3 is an equivalent circuit diagram of FIG. 2;

4A is an equivalent circuit diagram of FIG. 3, wherein FIG. 4A shows a case where an electrode is located on a molten metal layer, FIG. 4B shows a case where an electrode is located on a slag layer, and FIG. It shows the case where it is located in a layer.

FIG. 5 is a diagram showing a change in the potential of the electrode with the potential of the container as a reference potential when the electrode is moved upward from the molten metal layer to the atmospheric layer through the slag layer.

6A and 6B are explanatory diagrams of a method of measuring a moving speed of an electrode using two electrodes, wherein FIG. 6A shows the principle and FIG. 6B shows a change in potential of each electrode.

FIG. 7 is an explanatory view showing the principle of the first slag layer thickness and molten metal layer surface level position measuring method of the present invention.

FIG. 8 is an explanatory diagram showing a configuration of a slag layer thickness measuring device according to a first embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a structure of a joint portion between an electrode, a probe, and a lance in FIG. 8;

FIG. 10 is a display example of a display of a slag layer thickness measuring apparatus using a method of obtaining a moving distance from a moving time and a moving speed of an electrode according to the first embodiment.

11 (a), (b), (c), and (d) show the first
Example of display of change in electrode potential in a slag layer thickness measuring apparatus using the method of obtaining the moving distance from the moving time and moving speed of the electrode according to the embodiment

FIG. 12 is a cross-sectional view of a probe employing a feed screw mechanism.

FIG. 13 is a configuration diagram of a slag layer thickness measuring device used in combination with an oxygen concentration measuring device (1).

FIG. 14 is a configuration diagram of a slag layer thickness measuring device used in combination with an oxygen concentration measuring device (2).

FIG. 15 is an explanatory diagram showing a configuration of a slag layer thickness and molten steel layer surface level position measuring device according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 container 2 molten metal layer 3 slag layer 4 atmosphere layer 5 electrode 6 slag layer thickness 7 molten metal-slag interface passage point 8 slag-air interface passage point 9 fixed point 10 Distance from fixed point to surface of molten metal layer 11 DC power supply Vcc 12 Resistance Rx 13 Potential measuring means 19 Changeover switch 21 Electrode 22 Electrode 23 Measuring device 25 Vacuum tank 26 Immersion tube 27 Light source 28 Fixed point detection mark 29 Sensor 31 Converter 32 Molten steel layer 33 Slag layer 34 Atmosphere layer 35 Electrode 36 Probe 37 Lance 38 Lance moving device 39 Encoder 40a, 40b Measuring device 41 DC power supply Vcc 42 Resistance Rx 43 Electrode potential measurement circuit (analog circuit) 44 Lance movement control circuit 45 Encoder pulse count circuit 46 Fixed point detection circuit 47 Microcomputer 48 Display 49 Fixed point 51 Contact Contact 52 Ring contact 61 Lance (probe) 62 Rifle groove inner diameter 63 Lance holder 64 Lance holder mount 65 Electrode 71 Zirconia electrode 72 Liquid steel electrode 73 Oxygen probe 74 Oxygen concentration measuring instrument 75 Slag layer thickness measuring instrument 76 Quartz tube

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yukio Terauchi, Inventor 1-7-40 Mishimae, Takatsuki City, Osaka Prefecture Inside Hereus Electronite Co., Ltd. (72) Inventor Teruaki Kajikawa 1-7-E, Mishimae, Takatsuki City, Osaka Prefecture 40 Heres Electronite, Inc. F term (reference) 2F014 AA08 AC06 DA01 DA10 4K070 AB20 BE08 BE14

Claims (20)

[Claims] 1. A method for measuring a thickness of a slag layer of a molten metal in which a slag layer floats on a surface of a molten metal layer, wherein the molten metal layer occupies an upper layer of the slag layer through the slag layer. The electrode is moved upward to the atmospheric layer, and the electrode-container characteristic, which is the electric characteristic between the container containing the molten metal and the conductive container and the electrode, is monitored. From the conductivity due to the interposition of the molten metal layer when the electrode is immersed in the molten metal layer, the power is transferred to the power generation due to the interposition of the slag layer that moves to the slag layer and functions as an electrolyte. And the electrode escapes from the slag layer to the air layer, and the electrode-vessel characteristic shifts from the power generation property to the insulating property due to the interposition of the air layer. The point at which The lag-atmospheric interface passing time is detected, and from the molten metal-slag interface passing time to the slag-atmospheric interface passing time, the moving distance of the electrode is measured and the slag layer thickness is measured. Slag layer thickness measurement method. 2. A method for measuring a thickness of a slag layer of a molten metal in which a slag layer floats on a surface of a molten metal layer, the method comprising: The electrode is moved down to the metal layer, and the electrode-container characteristic, which is the electrical characteristic between the container containing the molten metal and the electrode having conductivity, is monitored. Atmospheric-slag at the time when the electrode shifts from the insulating property due to the interposition of the atmosphere when the electrode is in the atmospheric layer to the power generation property due to the interposition of the slag layer functioning as an electrolyte by immersing in the slag layer. At the time of passing through the interface, the slag at which the electrode moves from the slag layer to the molten metal layer, and the electrode-vessel characteristic shifts from the power generation property to the conductivity due to the interposition of the molten metal layer. Molten metal interface Along with detecting the passing time, the air-slag interface time to the slag-molten metal interface time, measuring the distance traveled by the electrode, the slag layer thickness as the slag layer thickness Measuring method. 3. A DC power supply Vcc having the electrode side as a cathode and a resistor Rx connected in series with the power supply are inserted between the electrode and the container, and the DC power supply Vcc and the resistor Rx are connected to each other. The value is set so that, when the electrode is immersed in the slag layer, the potential of the electrode with the potential of the container as a reference potential is a high potential higher than the reference potential. Is moved upward from the molten metal layer to the atmospheric layer, and the potential of the electrode with respect to the reference potential is measured.As the molten metal-slag interface point, the potential of the electrode is changed from the reference potential to the high potential. 2. The slag layer according to claim 1, further comprising: detecting a time point when the electrode changes from the high potential to a low potential lower than the reference potential as the slag-atmosphere interface time. Monitoring procedures. 4. A DC power supply Vcc having the electrode side as a cathode and a resistor Rx connected in series with the power supply are inserted between the electrode and the container, and the DC power supply Vcc and the resistor Rx are connected to each other. The value is set so that, when the electrode is immersed in the slag layer, the potential of the electrode with the potential of the container as a reference potential is a high potential higher than the reference potential. Is moved downward from the atmospheric layer to the molten metal layer, and the potential of the electrode with respect to the reference potential is measured.As the time of passage through the atmosphere-slag interface, the potential of the electrode is from a low potential lower than the reference potential. The slag layer according to claim 2, wherein a time point when the potential changes to the high potential is detected, and a time point when the potential of the electrode changes from the high potential to the reference potential is detected as the slag-molten metal interface passing time. Monitoring procedures. 5. The method according to claim 1, wherein the moving speed of the electrode is raised or lowered while the electrode is moved upward from the molten metal layer to the atmospheric layer. When the moving time of the electrode from the passage time to the slag-atmosphere interface passage time is measured, and the method of moving the electrode down from the atmosphere layer to the molten metal layer is used, the air-slag interface passage is used. From the time to the slag-molten metal interface passing time, measure the moving time of the electrode, instead of measuring the moving distance of the electrode, from the moving speed and the moving time of the electrode, by calculation The slag layer thickness measuring method according to claim 1, wherein the moving distance of the electrode is obtained. 6. An electrode, an electrically conductive container containing a molten metal in which a slag layer floats on the surface of the molten metal layer, and: An electrode moving means that moves upward to the atmosphere layer that occupies or moves downward from the atmosphere layer to the molten metal layer through the slag layer, and between the electrode and the container, the electrode side is a cathode. A DC power supply Vcc and a resistor Rx connected in series with the power supply are inserted, and the values of the DC power supply Vcc and the resistance Rx are set to the potential of the container when the electrode is immersed in the slag layer. A measuring circuit formed by setting the potential of the electrode to be higher than the reference potential as a reference potential; a potential measuring means for measuring the potential of the electrode with respect to the reference potential; and the potential measurement A time point at which the means detects the change from the reference potential to the high potential, a time point at which the high potential changes to a low potential lower than the reference potential, or a time point at which the low potential changes to the high potential And an electrode moving distance measuring means for measuring a moving distance of the electrode from a time point when the high potential changes to the reference potential. 7. An electrode, a conductive container containing a molten metal in which a slag layer floats on the surface of the molten metal layer, and a constant moving speed, the electrode being moved from the molten metal layer to the slag layer. Electrode moving means for moving upward through the slag layer to the atmospheric layer occupying the upper layer, or moving downward from the atmospheric layer through the slag layer to the molten metal layer, and between the electrode and the container. A DC power supply Vcc having the electrode side as a cathode and a resistor Rx connected in series with the power supply are inserted, and the values of the DC power supply Vcc and the resistance Rx are set such that the electrode is immersed in the slag layer. A measuring circuit formed by setting the potential of the electrode to be higher than the reference potential, using the potential of the container as a reference potential, and measuring the potential of the electrode with respect to the reference potential. Position measuring means, detected by the potential measuring means, from the time when the reference potential changes to the high potential, to the time when the high potential changes to a low potential lower than the reference potential, or the low potential From the point in time when the potential changes to the high potential, to the point in time when the potential changes from the high potential to the reference potential, an electrode moving time measuring unit that measures the moving time of the electrode, and the moving speed and the moving time of the electrode. And an electrode moving distance calculating means for calculating the moving distance of the electrode by calculation. 8. In addition to the electrodes, one electrode is added, the lower ends of these two electrodes are provided at a fixed distance in the moving direction, and two of these electrodes are simultaneously moved. A moving speed detecting means for measuring a time difference between potentials detected by the two electrodes with respect to the container and detecting the moving speed from the time difference and the fixed distance. A slag layer thickness measuring device according to claim 7. 9. The method according to claim 6, wherein the molten metal is molten steel.
The slag layer thickness measuring device according to any one of claims 1 to 8. 10. The slag layer thickness measuring apparatus according to claim 9, wherein the material of the electrode is an iron alloy containing at least one of Mo, Co, Cr, and Mn. 11. The slag layer thickness measuring apparatus according to claim 9, wherein said electrode is used in combination with a molten steel electrode of an oxygen probe for measuring oxygen concentration. 12. The electrode and the zirconia electrode of an oxygen probe for measuring oxygen concentration have the same lower end positions, and a portion other than both end portions is covered with a protective pipe such as a quartz tube. The slag layer thickness measuring device according to the above. 13. The slag layer thickness measuring apparatus according to claim 9, wherein said electrode is attached to a molten steel temperature measuring probe. 14. A molten metal having a slag layer floating on the surface of a molten metal layer, wherein the molten metal is located at a predetermined distance from the container above a predetermined distance from the container above the opening of the container having conductivity. A method for measuring the distance to the surface of the layer, and the thickness of the slag layer, comprising: an electrode from the molten metal layer to the fixed point in the atmosphere layer occupying the upper layer of the slag layer through the slag layer. When the electrode is immersed in the molten metal layer, the electrode-container characteristic, which is an electrical characteristic between the container and the electrode, is monitored by moving the electrode up and down. From the conductivity due to the interposition of the molten metal layer, a point at which the electrode moves to the slag layer and shifts to a power generation property due to the interposition of the slag layer functioning as an electrolyte, at the time of passing through the molten metal-slag interface, and the electrode Is the Escape from the lag layer to the atmosphere layer, the electrode-vessel characteristics, from the power generation, and the slag-at the time of transition to insulation due to the interposition of the atmosphere layer, and detecting the time passing through the air interface, From the time of passing the molten metal-slag interface to the time of passing the slag-atmosphere interface, the moving distance of the electrode was measured, and the thickness of the slag layer was determined.From the time of passing the molten metal-slag interface, A method for measuring a slag layer thickness and a molten metal layer surface level position as a distance from the fixed point to the surface of the molten metal layer by measuring a moving distance of the electrode to a fixed point. 15. A molten metal in which a slag layer floats on the surface of a molten metal layer, the molten metal being placed above an opening of a container having conductivity and being located at a predetermined distance from the container and at a predetermined distance from the container. A method for measuring the distance to the surface of the layer, and the thickness of the slag layer, wherein the electrode from the fixed point in the air layer occupying the upper layer of the slag layer to the molten metal layer through the slag layer. Lowering the container, and a container that contains the molten metal and has conductivity,
The electrode-container characteristic, which is an electrical characteristic between the electrode and the electrode, is monitored. At the time of passing through the air-slag interface, which is a point of transition to power generation by the interposition of the slag layer functioning as an electrolyte by immersing in the slag layer, the electrode moves from the slag layer to the molten metal layer, and the electrode -The inter-container characteristic detects the slag-molten metal interface passing time, which is the time when the power generation property shifts to the conductivity due to the interposition of the molten metal layer, and the slag-molten metal interface passing time from the fixed point. By the time, the moving distance of the electrode has been measured, and the distance from the fixed point to the surface of the molten metal layer has been measured. A method for measuring a slag layer thickness and a molten metal layer surface level position as a thickness of the slag layer by measuring a moving distance of the electrode by a time when the electrode passes through the surface. 16. A DC power source Vcc having the electrode side as a cathode and a resistor Rx connected in series with the power source are inserted between the electrode and the container, and the DC power source Vcc and the resistor Rx are connected. The value of is set such that when the electrode is immersed in the slag layer, the potential of the electrode with the potential of the container as a reference potential is a high potential higher than the reference potential, The electrode is moved upward from the molten metal layer to the atmospheric layer, and the potential of the electrode with respect to the reference potential is measured. The time when the potential changes to a potential, and the time when the potential of the electrode changes from the high potential to a low potential lower than the reference potential is detected as the slag-atmosphere interface time. Slag layer thickness and the molten metal layer surface level position measuring method. 17. A DC power source Vcc having the electrode side as a cathode and a resistor Rx connected in series with the power source, and the DC power source Vcc and the resistor Rx are inserted between the electrode and the container. The value of is set such that when the electrode is immersed in the slag layer, the potential of the electrode with the potential of the container as a reference potential is a high potential higher than the reference potential, The electrode is moved downward from the atmosphere layer to the molten metal layer, and the potential of the electrode with respect to the reference potential is measured.As the time of passage through the air-slag interface, the potential of the electrode is lower than the reference potential. The time when the potential changes from the high potential to the high potential, and the time when the potential of the electrode changes from the high potential to the reference potential is detected as the time of passing through the slag-molten metal interface. Slag layer thickness and the molten metal layer surface level position measuring method. 18. The method according to claim 18, wherein the moving speed of the upward movement or the downward movement of the electrode is made constant, and the method of moving the electrode upward from the molten metal layer to the atmospheric layer is used. For calculation, the moving time of the electrode from the time of passing the molten metal-slag interface to the time of passing the slag-air interface is measured, and for calculating the distance from the fixed point to the surface of the molten metal layer, the melting is performed. When the moving time of the electrode from the time of passing through the metal-slag interface to the fixed point is measured, and the method of moving the electrode down from the atmospheric layer to the molten metal layer is used, from the fixed point to the molten metal layer For the distance calculation to the surface of the, from the fixed point to the point of passing the slag-molten metal interface, measure the moving time of the electrode, for the thickness calculation of the slag layer Measuring the moving time of the electrode from the time of passing through the atmosphere-slag interface to the time of passing through the slag-molten metal interface; instead of measuring each moving distance of the electrode, the moving speed of the electrode The moving distance of each of the electrodes is obtained by calculation from the distance and each of the moving times.
The method for measuring a slag layer thickness and a molten metal layer surface level position according to any one of claims 4 to 17. 19. An electrode, an electrically conductive container containing a molten metal in which a slag layer floats on the surface of a molten metal layer, and: In the atmospheric layer occupying the upper layer, above the opening of the container, move upward to a fixed point located at a predetermined distance from the container, or from the fixed point in the atmospheric layer, the slag layer An electrode moving means for moving down through the electrode to the molten metal layer; a DC power supply Vcc having the electrode side as a cathode; and a resistor Rx connected in series with the power supply, between the electrode and the container. When the electrode is immersed in the slag layer, the values of the DC power supply Vcc and the resistance Rx are set to a potential higher than the reference potential with the potential of the container as a reference potential. Will be A measuring circuit formed by setting the potential of the electrode with respect to the reference potential; and for measuring the thickness of the slag layer, the potential measuring means detects the reference potential, From the time when the potential changes to a high potential, to the time when the potential changes from the high potential to a low potential lower than the reference potential, or from the time when the potential changes from the low potential to the high potential, from the high potential to the reference potential Up to the point of change, the slag layer thickness measuring electrode moving distance measuring means for measuring the moving distance of the electrode, and for measuring the distance from the fixed point to the surface of the molten metal layer, the potential measuring means detected The moving distance of the electrode from the time when the reference potential changes to the high potential to the fixed point, or from the fixed point to the time when the high potential changes to the reference potential. A slag layer thickness and molten metal layer surface level position measuring device, comprising: a molten metal layer surface level position measuring electrode moving distance measuring means for measuring separation. 20. An electrode, an electrically conductive container containing a molten metal in which a slag layer floats on the surface of the molten metal layer, and a method in which the electrode is moved from the molten metal layer to the slag layer at a constant moving speed. Through the air layer occupying the upper layer of the slag layer, above the opening of the container, upwardly moving to a fixed point located at a predetermined fixed distance from the container, or, An electrode moving means for moving downward from the fixed point through the slag layer to the molten metal layer; a DC power supply Vcc having the electrode side as a cathode between the electrode and the container; and a power supply connected in series with the power supply. When the electrode is immersed in the slag layer, the value of the DC power supply Vcc and the value of the resistor Rx are used as the reference potential with the potential of the container as the reference potential. Potential A measuring circuit formed so as to have a high potential, a potential measuring means for measuring the potential of the electrode with respect to the reference potential, and a potential measuring means for measuring the thickness of the slag layer. From the time when the reference potential changes to the high potential, to the time when the high potential changes to a low potential lower than the reference potential, or from the time when the low potential changes to the high potential, From a potential to the reference potential, to the point of time, the slag layer thickness measurement electrode movement time measuring means for measuring the movement time of the electrode, and for measuring the distance from the fixed point to the surface of the molten metal layer, From the time when the potential measuring means detects the change from the reference potential to the high potential to the fixed point, or from the fixed point to the time when the potential changes from the high potential to the reference potential. An electrode moving time measuring means for measuring the molten metal layer surface level position measuring the moving time of the electrode, and an electrode for calculating the moving distance of the electrode from the moving speed of the electrode and each of the moving times. A slag layer thickness and molten metal layer surface level position measuring device comprising: a moving distance calculating means;