KR20010055824A - Thicknes measurement apparatus of teel making slag - Google Patents

Abstract

PURPOSE: An apparatus for measuring the thickness of a steelmaking slag is provided which has simple system structure and obtains a high accurately and high efficiently measured value by measuring using a resistance difference between molten steel and molten slag, and minimizes measuring expenses by using a semi-permanent measuring probe. CONSTITUTION: The apparatus comprises a probe in which a detecting coil is mechanically jointed with a connector of a ceramic material having superior heat and impact resistance at a metallic protective pipe and the interface thereof; a driving part (8) in which the probe is installed and LM guide and ball screws are installed for lifting the probe by a motor (7), wherein an encoder (9) is installed in the motor (7) for controlling an ascending and descending speed and an ascending and descending distance by controlling the position according to the rotation of the motor (7); an indicating part (10) connected to the encoder (9) for indicating the position and speed of the driving part (8); and a GPIB (13) connected between a multimeter (11) connected to an electrode terminal of the probe for measuring signals measured at the electrode terminal and a computer (12) processing the measured signals so as to transmit signals using a RS232C connector.

Description

Steelmaking slag thickness measuring equipment {THICKNES MEASUREMENT APPARATUS OF TEEL MAKING SLAG}

The present invention relates to a steel slag thickness measuring apparatus that can quickly and accurately measure the thickness of the slag floating on the surface of the molten steel during the steelmaking process.

In general, slag that floats to the surface of molten steel during the steelmaking process acts as a heat insulator to prevent the temperature of molten steel from decreasing, while it degrades the refractory in the ladle or decreases the reaction efficiency in the molten steel and also impairs the cleanliness of molten steel such as shelling I'm making it.

It is well-known that slag thickness management is particularly important in the manufacturing process when manufacturing high-quality steel. In the case of stainless steel, which is a high value-added product of steel, CaO is added to ensure proper basicity (2.2 to 2.4). , desulfurization and serve to remove absorbed water to inject the CaF ₂ on the other hand, perform refining operations, such as in, etc. Fe-Si, Al and Ti in order to reduce the degree of oxidation of the slag, but calculates the input reference amount of these additives To this end, there is an urgent need for a device capable of measuring accurate data on the thickness of slag.

Conventionally, methods for using molten slag and molten steel inherent physical properties, ie, density and specific gravity, sound absorption, or using an electromagnetic sensor have been invented to measure the thickness of the slag.

The conventional method described above uses a pressure sensor, an optical sensor, an ultrasonic sensor, an electromagnetic sensor, and a buoyancy sensor to measure the steel slag thickness. However, since the measurement environment is very poor, most methods have significant limitations until practical use. It is not reaching.

Among the typical measuring methods, the electromagnetic sensor is a measuring system composed of emitter and recever coil. The first sensor measures the distance from the atmosphere to the molten metal interface and the second sensor discriminates the air and slag interface. Finally, the slag thickness is calculated.

However, such a measuring system has the disadvantage that the measuring system is sold at a high price while the reliability of the measuring accuracy is high, and the cost of measuring is increased by replacing the carddboard sleeve, which is a probe protector, every measurement.

In addition, the measurement system using buoyancy can be regarded as a permanent system in terms of measurement cost, but the measurement accuracy is lower than that of the existing measurement system.

In other words, this method using buoyancy is a method using the specific gravity difference between slag and molten steel, and the immersion rod passes through the atmosphere / slag interface and the slag / molten steel interface, and the buoyancy difference according to the change in specific gravity is measured using the load cell as a load measuring sensor. That's how.

However, in this method, the measurement value is changed according to the depth of the immersion rod and the amount of slag detected according to the weight change. Therefore, it is difficult to accurately determine the interface and the manufacturing cost is high.

On the other hand, the protective tube when immersed in molten steel uses ceramic materials such as Cordierite, Alumina, and Zircornia, but most of them have low thermal shock resistance and are difficult to use semi-permanently due to wetting with slag. In the case of 500mm or more, it is difficult to manufacture, and some materials are expensive and there is a problem in that the measurement cost increases when using a consumable probe.

The present invention has been invented to solve the above problems, the present invention can be measured using the resistance difference between molten steel and molten slag, the configuration of the system is simple and high accuracy and high efficiency can be obtained and semi-permanent It is an object of the present invention to provide a steel slag thickness measuring apparatus that can minimize the measurement cost by using a measurement probe.

The present invention for achieving the above object is to install the detection coil and the electrode terminal of the oxidation resistant high melting point metal wire inside the protective tube made of metal material for measuring the thickness of the slag, the protective tube to insulate the detection coil The inside is filled with fine ceramic powder, which is an insulator, and the detection coil is a probe formed by mechanically fastening a ceramic connector having excellent thermal shock resistance at the interface between a metal protective tube and the interface, and the probe is installed in the motor. An LM guide and a ball screw are installed therein to be elevated by the drive. The motor has a drive unit installed with an encoder for controlling the lifting speed and the lifting distance by controlling the position according to the rotation of the motor, and the drive unit is connected to the encoder. And a display unit for displaying a speed and an electrode connected to an electrode terminal of the probe. Between a computer for processing the measured signal with a multimeter which measures the signal measured on a chair doengeot hayeoseo including GPIB connected to deliver a signal using the RS232C connector.

1 is a cross-sectional view showing a probe according to the present invention,

2 is a schematic view showing a measuring device according to the present invention;

Figure 3 is an illustration of the cold test results measured by the measuring device according to the present invention,

4 is an exemplary view of a hot test result measured by the measuring device according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: probe 2: protective tube

3: detection coil 4: electrode terminal

5: insulator 6: connector

7 motor 8 drive unit

9: Encoder 10: Display

11: multimeter 12: computer

13: GPIB

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 and 2.

1 is a cross-sectional view showing a probe according to the present invention, the probe 1 of the present invention is that the difference in the resistance difference between the slag and molten steel is at least 10 ³ order, the protective tube (2) when immersed in the molten metal There is a possibility of melting, but the latent heat of melting is required to dissolve the metal, so it is formed of a metal material to maintain sufficient strength when the immersion time is very short, and the detection of the oxidation resistant high melting point metal wire inside the protective tube 2 The coil 3 and the electrode terminal 4 are provided.

In addition, in order to insulate the detection coil 3, the inside of the protection tube was filled with a ceramic powder in an insulated state, which is an insulator 5, and the detection coil has a ceramic connector 6 having excellent thermal shock resistance. By mechanically fastening at the interface, insulation with the protective tube 2 was maintained.

On the other hand, Figure 2 is a schematic view of the measuring device of the present invention, the probe 1 is installed on one side of the drive unit 8 is lifted by the motor (7), the LM guide and ball screw is provided inside the drive unit (8) The motor 7 is provided with an encoder 9 for controlling the elevation speed and the elevation distance by controlling the position of the driving unit 8 in accordance with the rotation of the motor 7.

In addition, the encoder 9 is connected with a display unit 10 for displaying the position and speed of the driving unit 8, and the electrode terminal 4 of the probe 1 measures the signal measured by the electrode terminal 4. The multimeter 11 for this purpose is provided.

A GPIB 13 is connected between the multimeter 11 and the computer 12 processing measurement data using a RS232C connector.

Hereinafter, an embodiment of the present invention will be described.

Example 1

In order to verify the function of the steelmaking slag thickness measuring apparatus of the present invention, a measuring device having the following specifications was manufactured and subjected to a low temperature test.

-Slag thickness measurement accuracy: 0.2mm

-Speed up and down: 3.6m / min (max)

Probe stroke: 100mm

-Horizontal and elevating movement distance: 260 ~ 400mm, 300 ~ 450mm

To conduct low temperature test, there is a big difference in mutual electrical conductivity among materials existing in the liquid phase at room temperature, and it is distinctly divided into two layers by specific gravity difference. It is electrolyte CuCl ₂ (specific gravity: 1.5) and insulator petroleum chemicals Specific gravity: 0.9) was selected and the thickness measurement experiment was performed.

As shown in FIG. 1, the probe A was made of Pt having a diameter of 1 mm, the insulator 5 was made of Alumina powder, and the protective tube 2 was made of sus316.

In the interface determination between two liquids, the probe descends at a constant speed and measures the resistance value, so that the interface value can be accurately identified when the resistance value is greatly changed when the resistance value is in contact with another medium interface.

It can be seen that the interface between the medium is clearly distinguished as shown in Figure 3 showing the results of the experiment, material 1 of Figure 3 is petroleum chemicals and material 2 is the electrolyte CuCl ₂ It can be seen that the thickness of the material 1 is 7mm It is judged to be very excellent in terms of efficiency and measurement accuracy of the inventor's measurement system.

Example 2

In order to verify the function of the present invention steel slag thickness measuring apparatus was examined in the molten steel state as follows.

In the slag thickness measurement experiment, steel scrap 60Kg was first dissolved using an induction furnace (3KHz, 125KW class: capacity 100Kg, crucible diameter 200mm), and then steelmaking slag (CaO-SiO ₂ -MgO-Al ₂ O ₃ ) was about 3.5Kg. Was prepared to prepare a slag thickness measurement experiment.

In the slag thickness measurement, the resistance value detected while lowering the probe A installed on the side by induction melting by using the probe and measuring device manufactured in Example 1 was confirmed.

The measurement results molten's lag, and the resistance of the molten metal will clear the slag / molten metal interface is determined by difference between the car 10 ³ order cross resistance to each 1~40㏀ and 0.5~1Ω was possible.

That is, as shown in FIG. 4, the slag thickness was about 15 mm in the present experiment, and thus the slag measurement was easily possible by using the resistance difference. When the present inventors fabricated the slag measurement system in the field application scale, It is considered to be applicable at the time of operation.

In addition, the probe produced in the present invention exhibits the same measurement accuracy even when directly and repeatedly immersed in molten slag and molten steel, so that durability can be used semi-permanently unless the electrode terminal of the probe is damaged.

As described above, the present invention can measure molten steel level such as L / D converter and ladle in steel mill, as well as slag thickness measurement, and can be applied to a system that can prevent slopping. It is a very useful invention that it is easy to change and the device configuration is simple to minimize the cost.

Claims (1)

In measuring the thickness of slag floating on the surface of molten steel during the steelmaking process, In order to measure the thickness of the slag, a detection coil 3 and an electrode terminal 4 made of an oxidation resistant high melting point metal wire are provided inside the protective tube 2 made of a metal material, and the insulation coil 3 is insulated. In order to fill the inside of the protective tube, an insulator (5) ceramic powder is charged, and the detection coil (3) has a ceramic connector (6) having excellent thermal shock resistance at the metallic protective tube (2) and its interface. A probe 1 which is mechanically fastened, an LM guide and a ball screw are installed inside the probe 1 so that the probe 1 is lifted up and down by the motor 7, and the motor 7 is rotated by the motor 7. Therefore, the driving unit 8 is provided with an encoder 9 for controlling the position and the lifting speed and the lifting distance by controlling the position, and the display unit 10 connected to the encoder 9 to display the position and speed of the driving unit 8. ) And the electrode terminal 4 of the probe 1 A configuration including a GPIB 13 connected between the multimeter 11 measuring the signal measured at the electrode terminal 4 and the computer 12 processing the measured signal by using an RS232C connector. Steel slag thickness measuring device, characterized in that