JPH09166407A - Device for measuring layer thickness of melted slug and measuring method using the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To very accurately measure the layer thickness of a melted slug. SOLUTION: Electrodes 4a and 4b of a probe 4 are inserted into the layer of a melted slug 3 a non-contact distance meter 5 is instructed to start a measurement at the time point when the electrodes 4a and 4b have passed the layer of the melted slug 3 and the tip has reached the interface between the melted slug 3 and a melted metal 2. The distance to the upper surface of the melted slug 3 is measured by the non-contact distance meter 5 based on the instruction and the layer thickness of the melted slug is calculated from the distance measurement value and the length of the electrodes 4a and 4b which are given previously, thus accurate measuring of the layer thickness of the melted slug is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten slag layer thickness measuring device and a measuring method using the same.

[0002]

2. Description of the Related Art Conventionally, the layer thickness of molten slag which coexists and coexists on molten metal in a ladle in a secondary refining furnace such as a converter and VOD is, for example, JP-A-53-91771 or JP-A-58. An automatic measuring method or device as disclosed in Japanese Patent Publication No. 166221 is used.

That is, in the contents of JP-A-53-91771 or JP-A-58-166221, a probe having two electrodes attached to its tip is lowered from the upper surface of the molten slag layer to the molten metal layer to melt the molten slag. The difference in electrical conductivity between the molten metal and the molten metal is detected as a change in the resistance value between the electrodes, and the probe descending distance between them, that is, the thickness of the molten slag layer, is measured from the electrical signal sent in conjunction with the probe lifting device. To do.

[0004]

However, in the case of the above-mentioned JP-A-53-91771 or JP-A-58-166221, the control of the lifting device is complicated and requires a high precision, and the accuracy is high. Since high rigidity is required for the entire lifting device in order to perform accurate measurement, there is a problem that the manufacturing cost of the measuring equipment becomes high. Also, since it is normal that the molten slag on the molten metal is partially solidified,
The change in electrical conductivity between the two electrodes does not always become sharp, so it is difficult to determine the upper surface of the molten slag clearly.

An object of the present invention is to provide a molten slag layer thickness measuring device and a measuring method using the same, which solves the problems of the prior art as described above.

[0006]

SUMMARY OF THE INVENTION The present invention is an apparatus for measuring the layer thickness of molten slag separated and coexisting on the upper side of molten metal in a container, which is positioned above the container opening and can be vertically moved up and down. A probe having two electrodes each having a predetermined length, a non-contact distance meter integrally attached to the probe, and a resistance detection circuit for detecting a resistance change between the two electrodes of the probe, A comparison circuit for instructing the measurement start of the non-contact distance meter by comparing the voltage signal from the resistance detection circuit with the upper limit voltage setting value, and the measurement signal of the non-contact distance meter based on the measurement start command from the comparison circuit. And a calculation circuit for calculating the molten slag layer thickness by inputting the input signal, and a molten slag layer thickness measuring device.

In the method of measuring the layer thickness of the molten slag by using the above-mentioned layer thickness measuring device, the present invention further comprises the step of inserting the electrode of the probe into the layer of the molten slag, and the electrode The step of instructing the non-contact distance meter to start measurement when the tip reaches the interface between the molten slag and the molten metal after passing through the layer, and the upper surface of the molten slag by the non-contact distance meter based on this instruction And a step of calculating a molten slag layer thickness from the distance measurement value and a value of the length of the electrode given in advance, and a layer thickness measuring method of the molten slag. Is.

[0008]

[Operation] According to the present invention, when the electrode of the probe reaches the interface between the molten slag and the molten metal, the distance to the upper surface of the molten slag is measured using a non-contact distance meter, and the measured value Since the layer thickness of the molten slag is calculated using the value of the length of the electrode, the molten slag layer thickness can be measured with high accuracy.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing an outline of a resistance detection circuit used in the present invention. In FIG. 1, 1 is a container having an opening such as a ladle, 2 is a molten metal in the container 1,
Reference numeral 3 is a molten slag that coexists on the upper side of the molten metal 2. Reference numeral 4 denotes a probe composed of two electrodes 4a and 4b, which is located above the opening of the container 1 and can be vertically moved by an elevating device (not shown). Can be freely inserted into. The electrodes 4a,
4b is held at a predetermined interval by a holder 4c. The material of the electrodes 4a and 4b is, for example, a refractory metal such as molybdenum or tungsten, or graphite. Reference numeral 5 denotes, for example, a laser-type non-contact distance meter attached integrally to the holder 4c of the probe 4.

Reference numeral 6 is a resistance detection circuit for detecting a resistance change of the probe 4, 7 is a comparison circuit in which an upper limit setting voltage E _UL is set, and a comparison is made, and 8 is a signal from the comparison circuit 7 and is received from the non-contact distance meter 5. An arithmetic circuit for arithmetically processing the measurement signal of, and 9 is a counting display device. Here, the resistance detection circuit 6, as shown in FIG. 2, the resistance R ₀ and the power supply S is probe 4 comprising voltage E
Of the resistance R ₀
The divided voltage E _{0 at} both ends of is inputted to the comparison circuit 7 as a voltage change signal.

The operation of measuring the layer thickness of the molten slag by using the molten slag layer thickness measuring device of the present invention thus constructed will be described below. First, the probe 4 and the non-contact distance meter 5 waiting at a predetermined position above the opening of the container 1.
Is lowered to insert the electrodes 4a and 4b from the upper surface of the layer of the molten slag 3. Electrode 4 immediately before entering molten slag 3
Since the resistance value between a and 4b is infinite, the partial voltage E ₀ of the resistance R ₀ of the resistance detection circuit 6 shown in FIG. 2 is 0V. The magnitude of the descending speed of the probe 4 at this time does not need to be particularly limited, and may not be a constant speed. Further, the distance L _P between the detection element of the non-contact distance meter 5 and the tips of the electrodes 4a, 4b is stored in the arithmetic circuit 8 in advance.

Next, when the electrodes 4a and 4b are infiltrated into the layer of the molten slag 3, the resistance value between the electrodes 4a and 4b at that time is from infinity to the interval and shape of the electrodes 4a and 4b and the physical properties of the molten slag 3. changes to the resistance value R ₁ which is determined from such a partial pressure E ₀ of the resistor R ₀ is from _{0V {R 0 / (R 0} + R
₁ )} ・ E (V). Furthermore, the electrodes 4a, 4b
When passing through the layer of the molten slag 3 and reaching the interface between the molten slag 3 and the molten metal 2 as shown in FIG. 3, the resistance value between the electrodes 4a and 4b is Since it is almost 0Ω unlike the resistance of No. 2, the voltage division E ₀ of the resistance R ₀ of the resistance detection circuit 6 becomes substantially equal to the voltage E of the power source S.

Therefore, in the comparison circuit 7, this partial pressure E _{0 is obtained.}
When it is determined that E _UL <E ₀ ………… (1) by comparing the upper limit setting voltage E _UL with the upper limit setting voltage E _UL , a measurement start command is output to the arithmetic circuit 8 and at the same time, the counting display device 9 Is reset to 0. Next, the distance L _S to the upper surface of the molten slag 3 at that time is measured by the non-contact distance meter 5 and input to the arithmetic circuit 8. Then, the calculation circuit 8 calculates the layer thickness D of the molten slag 3 by the following equation (2).

[0014] _{D = L P -L S .................. (} 2) outputs a molten slag layer thickness D obtained by the arithmetic circuit 8 In this way the counting display device 9 to display.

[0015]

As described above, according to the present invention,
When the electrode of the probe reaches the interface between the molten slag and the molten metal, measure the distance to the upper surface of the molten slag using a non-contact distance meter, and use this measurement value and the length value of the electrode. Since the layer thickness of the molten slag is calculated, even with adverse conditions such as vibration during operation, it is possible to measure instantaneously and with high accuracy by a simple means.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an outline of a resistance detection circuit used in the present invention.

FIG. 3 is an explanatory diagram of the operation of the present invention.

[Explanation of symbols]

 1 Container 2 Molten Metal 3 Molten Slag 4 Probe 4a, 4b Electrode 4c Holder 5 Non-contact Distance Meter 6 Resistance Detection Circuit 7 Comparison Circuit 8 Arithmetic Circuit 9 Count Display Device

Claims (2)

[Claims] 1. A device for measuring the layer thickness of molten slag that separates and coexists on the upper side of molten metal in a container, the device being located above the container opening and having a predetermined length capable of vertically moving up and down. A probe consisting of a book electrode,
A non-contact distance meter integrally attached to the probe, a resistance detection circuit for detecting a resistance change between two electrodes of the probe, and a voltage signal from the resistance detection circuit are compared with an upper limit voltage set value. From a comparison circuit for instructing the measurement start of the non-contact distance meter, and an arithmetic circuit for inputting the measurement signal of the non-contact distance meter based on the measurement start instruction from the comparison circuit to calculate the molten slag layer thickness A layer thickness measuring device for molten slag, characterized in that 2. A method for measuring the layer thickness of a molten slag using the layer thickness measuring device according to claim 1, wherein the electrode of the probe is inserted into the layer of the molten slag, and the electrode is a layer of the molten slag. And the step of instructing the non-contact distance meter to start measurement at the time when its tip reaches the interface between the molten slag and the molten metal, and based on this command, up to the upper surface of the molten slag with the non-contact distance meter. A step of measuring the distance, a step of calculating the molten slag layer thickness from the distance measurement value and the value of the length of the electrode given in advance,
A method for measuring the layer thickness of molten slag, comprising: