KR20060074399A - Apparatus for measuring immersing depth of submerged entry nozzle - Google Patents

Abstract

The present invention relates to an apparatus for measuring the depth of deposition of an immersion nozzle, comprising: a measurement target installed on a tundish provided with an immersion nozzle at a lower portion thereof; A non-contact distance measuring sensor measuring a distance from the measurement target; Contact sensing means provided at an upper end of the mold; Monitoring means for providing contact data between the contact sensing means and the immersion nozzle; And a calculating means for receiving a moving distance of the measurement target measured by the distance measuring sensor after the contact data is provided by the monitoring means and calculating a depth at which the immersion nozzle is deposited on a mold. By accurately calculating the deposition depth of the immersion nozzle in the mold, it is possible to improve the quality of the product produced by the playing process.

Contactless sensor, aluminum wire, measuring target

Description

Immersion Nozzle Depth Depth Measurement Device {APPARATUS FOR MEASURING IMMERSING DEPTH OF SUBMERGED ENTRY NOZZLE}             

1 is a schematic view showing the installation state of the tundish, immersion nozzle and mold during continuous casting of a typical steel;

2 is a view showing the configuration of an immersion nozzle deposition depth measuring apparatus according to an embodiment of the present invention;

3 is a view showing a state of measuring the actual deposition depth of the immersion nozzle according to an embodiment of the present invention;

4 is a view showing the configuration of an immersion nozzle deposition depth measuring apparatus according to another embodiment of the present invention;

5 is a view showing a state of measuring the actual deposition depth of the immersion nozzle according to another embodiment of the present invention;

6 is a graph showing a comparison between the depth of deposition measured by the apparatus of FIG. 2 and the apparatus of FIG. 4 and the depth of deposition measured by the conventional example;

7 is a graph showing the comparison of the steelmaking defect index when the depth of the immersion nozzle is adjusted using the apparatus of FIG. 2 and the apparatus of FIG. 4 and the general apparatus.                 

<Description of Symbols for Major Parts of Drawings>

1: tundish

3: immersion nozzle

5: mold

10: calculation means

12: distance measuring sensor

14: measurement target

16: monitoring means

18: contact detection means

The present invention relates to a device for measuring the depth of deposition of the immersion nozzle for injecting molten steel into the mold in the continuous twisted casting, and more specifically to the immersion by calculating the falling height of the tundish in a non-contact sensing method using a laser sensor A device is capable of measuring the depth at which a nozzle is deposited on molten steel in a mold.

In general, the continuous casting process is a process of continuously producing a cast steel of a predetermined shape while the molten steel received in the tundish passes through the mold through the immersion nozzle. Referring to FIG. 1, molten steel contained in the tundish 1 during continuous casting of the steel is lowered through the immersion nozzle 3, and thereafter, to the mold 5 through the molten steel discharge port 3a of the immersion nozzle 3. Inflow. Molten steel introduced into the mold 5 is solidified while passing through the mold 5 to produce a cast steel. At this time, the molten steel in the mold 5 is maintained at a constant depth (h) from the upper end of the mold 5 to form the hot water surface ML.

On the other hand, the lower part of the immersion nozzle (3) is deposited on the molten steel in the mold (5) to maintain the depth derived to the optimum deposition depth. The depth of deposition h2 of the immersion nozzle 3 is defined as the distance from the hot water surface 3 to the upper end of the molten steel discharge port 3a. The molten steel exiting the discharge port 3a forms a flow like an arrow in the mold 5.

Since the flow pattern of the molten steel has a decisive influence on the quality of the continuous casting product, controlling the flow pattern of the molten steel in the mold is important to control the quality of the product. The most important factor controlling the flow of molten steel in the mold is the depth of deposition of the immersion nozzle. Therefore, controlling the optimal depth of deposition is very important for improving the quality of performance products.

However, in the conventional continuous casting process, the control method for the depth of deposition of the immersion nozzle is performed by the operator's neck or by using a jig that directly measures the depth of deposition.

In this conventional method, there is a disadvantage that the difference between the measured deposition depth and the actual deposition depth is very large and the difference from the actual post-casting set point is large. In addition, when the continuous casting time is long, the refractory loss is severe, and when the immersion nozzle deposition depth is changed in the middle of casting, the error is further increased by lowering or raising the neck side.                         

In addition, there was a difficulty in evaluating continuous casting and quality analysis of performance products because data on the depth of immersion nozzle immersion during casting was not obtained.

Accurately measure the depth of immersion nozzles in the mold during continuous casting and display the measurement results for easy viewing by operators.The measured depth of deposits is stored on the computer on-line to evaluate the quality of performance products and The purpose of the present invention is to provide an immersion nozzle immersion depth measuring apparatus that can measure the immersion nozzle depth by a non-contact method using a laser sensor, which is an ultra-precision distance sensor, for use in the evaluation of continuous casting industry.

In order to achieve the above object, in accordance with an embodiment of the present invention, the immersion nozzle depth measurement device is a measurement target installed in the tundish provided with the immersion nozzle at the bottom; A non-contact distance measuring sensor measuring a distance from the measurement target; And a calculating means for calculating a depth at which the immersion nozzle is deposited in a mold by receiving a moving distance of the measuring target after measuring the distance from the measuring target by the distance measuring sensor.

According to another embodiment of the present invention, the deposition depth measuring apparatus of the immersion nozzle includes a measurement target installed in the tundish provided with the immersion nozzle at the bottom; A non-contact distance measuring sensor measuring a distance from the measurement target; Contact sensing means provided at an upper end of the mold; Monitoring means for providing contact data between the contact sensing means and the immersion nozzle; And calculating means for calculating the depth at which the immersion nozzle is deposited in the mold by receiving the moving distance of the measurement target measured by the distance measuring sensor after the contact data is provided by the monitoring means.

The non-contact distance measuring sensor is preferably any one of an ultrasonic sensor, an optical sensor, an optical fiber sensor, an optical fiber sensor, an infrared sensor, a magnetic sensor, an ultraviolet sensor, and a laser sensor.

In addition, the contact sensing means is preferably an aluminum wire as a member that can be melted by contact with the immersion nozzle.

More preferably, the calculating means is the depth of the deposition nozzle immersion nozzle,

d1 = (D-Do)-K; Or d2 = E-(S1 + S2);

Calculated by

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention, the same configuration will be assigned the same reference numerals.

First, the continuous casting facility guides the mold 5 to produce the cast steel, the tundish 1 located above the mold 5, and the molten steel received in the tundish 1 to the mold 5. Immersion nozzle 3 is included. In the continuous casting process by the continuous casting equipment, the molten steel from the tundish 1 passes through the molten steel discharge port 3a of the immersion nozzle 3 while the immersion nozzle 3 is deposited on the molten steel in the mold 5. As it is discharged and solidified, the slabs are produced continuously.                     

At this time, according to one embodiment of the present invention, the apparatus for measuring the depth of the deposition of the immersion nozzle is deposited in the molten steel in the mold as shown in Figure 2 and the measurement target 14 provided in the tundish (1), It includes a non-contact distance measuring sensor 12 for measuring the distance to the measurement target (14).

The measurement target 14 is a member for specifying a position for measuring the moving distance of the tundish, and may be configured, for example, as a plate member. The position at which the measurement target 14 is installed is not limited thereto, but is preferably installed to protrude therefrom from the side of the tundish 1.

The non-contact distance measuring sensor 12 is not limited thereto, but is installed at a position spaced upwardly from the tundish 1. This is to prevent the distance measuring sensor 12 from being damaged by the high temperature of the continuous casting facility. In addition, the non-contact distance measuring sensor 12 is a means for measuring the distance in a non-contact manner, for example, any one of an ultrasonic sensor, an optical sensor, an optical fiber sensor, an optical fiber sensor, an infrared sensor, a magnetic sensor, an ultraviolet sensor, a laser sensor. Can be selected.

In addition, the immersion nozzle deposition depth measuring apparatus according to the present invention further includes a calculation means 10 for receiving the distance data with the measurement target 14 provided from the non-contact distance measuring sensor 12. The calculation means 10 receives the distance data and calculates the depth of deposition of the immersion nozzle 3 in the mold 5. The calculating means 10 may be constituted by a computer in which a predetermined calculation program is embedded.

The calculation program built in the calculation means 10 calculates the deposition depth d1 of the immersion nozzle by the following equation 1,

d1 = (D-Do)-K ‥‥‥‥‥‥ (1)

It consists of.

In Equation 1, D is a distance between the distance measuring sensor 12 and the measurement target 14 during continuous casting, Do is a distance between the distance measuring sensor 12 and the measurement target 14 before continuous casting, K Is the distance between the hot water ML of the molten steel in the mold 5 and the upper end of the molten steel discharge port 3a of the immersion nozzle 3 before continuous casting.

In addition, the deposition depth of the immersion nozzle 3 calculated by the calculation means 10 through Equation 1 described above may be displayed in real time on a monitor and provided to the operator.

That is, the deposition depth measuring apparatus according to an embodiment of the present invention is installed by measuring the distance measuring sensor 12 in a fixed position and attaching the measurement target 14 to the tundish 1 moving up and down. ) And the depth of deposition of the immersion nozzle 3 deposited in the mold 5 by measuring the distance between the target and the measurement target (14).

Hereinafter, the operation of the immersion nozzle deposition depth measuring apparatus according to an embodiment of the present invention.

Referring back to FIG. 2, before performing the continuous casting process, the distance measuring sensor 12 measures the distance Do from the measurement target 14 installed in the tundish 1 and calculates this data. To provide. In this case, the calculation means 10 is also provided with a distance K between the hot water surface ML of the molten steel in the mold 5 and the upper end of the molten steel discharge port 3a of the immersion nozzle 3.                     

And, as shown in Fig. 3, when the tundish 1 starts the lowering operation, that is, when the tundish 1 is lowered to the casting condition position to reach the state where the casting start preparation is completed, the distance The measuring sensor 12 measures the distance D from the measuring target 14 installed in the tundish 1 and provides this data to the calculating means 10.

At this time, the calculation means 10 substitutes the above-mentioned data into the above equation 1 to deposit depth d1 of the immersion nozzle 3, that is, the molten steel ML of the molten steel in the mold 5 and the molten steel of the immersion nozzle 3. The depth between the upper ends of the discharge ports 3a is calculated and displayed on the monitor as necessary.

On the other hand, according to another embodiment of the present invention, the apparatus for measuring the depth of the deposition of the immersion nozzle is deposited in the molten steel in the mold, as shown in Figure 4 and the measurement target 14 provided in the tundish (1), Non-contact distance measuring sensor 12 for measuring the distance to the measurement target 14, and monitoring means connected to the contact sensing means 18 and the contact sensing means 18 provided at the upper end of the mold 5 to enable signal transmission. (16).

The measurement target 14 and the non-contact distance measuring sensor 12 are similar to those described with reference to FIGS. 2 and 3, and thus will be omitted here.

The contact sensing means 18 is a member capable of sensing contact with the immersion nozzle 3 descending to the mold 5 side, and is preferably made of a low melting point member that can be melted. The low melting point member refers to a member that can be easily melted by the high heat transmitted through the immersion nozzle 3 from the molten steel received in the tundish 1. Such a low melting point member may be composed of, for example, a wire made of aluminum.                     

The monitoring means 16 monitors the moment when the falling immersion nozzle 3 contacts the contact sensing means 18 and the contact sensing means 18 is melted.

Further, the immersion nozzle immersion depth measuring apparatus according to the present invention includes calculation means for receiving the distance data provided from the non-contact distance measuring sensor 12 and the contact data of the immersion nozzle 3 and the contact sensing means 18 provided from the monitoring means ( 10) further includes. The calculation means 10 receives the above-described distance data and contact data to calculate the depth of deposition of the immersion nozzle 3 in the mold 5.

At this time, the contact data acts as data for setting an initialization state when the calculation means 10 calculates the depth of deposition of the immersion nozzle 3. Therefore, when the contact data is provided from the monitoring means 16 to the calculating means 10, the calculating means 10 then determines the depth of deposition of the immersion nozzle 3 from the distance data provided from the distance measuring sensor 12. Will be calculated.

The calculating means 10 may be constituted by a computer in which a predetermined calculation program is embedded, and in this case, the calculation program built in the calculation means 10 may calculate the deposition depth d2 of the immersion nozzle.

d2 = E-(S1 + S2) ‥‥‥‥‥‥ (2)

It consists of.

In Equation 2, E is the moving distance of the measurement target 14 measured by the distance measuring sensor 12 after the contact data is provided from the monitoring means 16, which is shown in FIG. The lower end is the distance from the upper end of the mold 5 to the position where it is deposited in the molten steel in the mold 5, that is, the depth or movement distance. S1 is the distance between the top surface ML of the mold 5 at the upper end of the mold 5, and S2 is the distance from the lower end of the immersion nozzle 3 to the upper end of the molten steel discharge port 3a.

In addition, the deposition depth d2 of the immersion nozzle 3 calculated by the calculation means 10 through the above-described equation 2 may be displayed in real time on a monitor and provided to the operator.

Thus, according to another embodiment of the present invention, as shown in Fig. 4, the contact sensing means 18, for example, aluminum wires are installed on the top of the mold, which always ensures the correct position. As the immersion nozzle 3 preheated by the molten steel descends and the lower end of the immersion nozzle 3 contacts the aluminum wire, the aluminum wire is melted and cut, and the lower end of the immersion nozzle 3 is cut at the upper end of the mold 5. It was possible to detect the passing point.

At the moment when the lower end of the immersion nozzle 3 passes the upper end of the mold 5, the monitoring means 16 provides contact data to the calculation means 10, and the calculation means 10 is the immersion nozzle 3. Maintain the initialization state to calculate the deposition depth of. Thereafter, the deposition depth of the immersion nozzle 3 is calculated by the above equation (2).

Hereinafter, the operation of the immersion nozzle deposition depth measuring apparatus according to another embodiment of the present invention.

Referring to FIG. 4 again, if the monitoring means 16 monitors the moment when the lower end of the immersion nozzle 3 contacts the contact detecting means 18 after the tundish 1 starts the lowering operation, the monitoring means ( 16 provides corresponding contact data to the calculation means 10. At this time, the distance S2 from the lower end of the immersion nozzle 3 to the upper end of the molten steel discharge port 3a and the hot water ML of the molten steel in the mold 5 at the upper end of the mold 5 are also calculated. To the means 10. In addition, the distance measuring sensor 12 measures the initial position of the measurement target 14 at the moment when the lower end of the immersion nozzle 3 contacts the contact detecting means 18.

And, as shown in Figure 5, when the tundish 1 is fixed to a predetermined position, that is, when the tundish 1 is lowered to the casting condition position and is ready to start casting, the distance measuring sensor 12 Measure the target position with the measurement target 14 installed in the tundish 1 and also after the distance between the target position and the initial position, that is, the lower end of the immersion nozzle 3 is in contact with the contact detecting means 18 The tundish 1 descends and measures the moving distance E moved, and provides this data to the calculation means 10.

At this time, the calculation means 10 substitutes the above-described data into the above equation 2 to calculate the depth of dimmer of the immersion nozzle 3, and displays it on the monitor as necessary.

On the other hand, in order to evaluate the accuracy of the immersion depth of the immersion nozzle after the casting is finished, the immersion nozzle was recovered and the actual immersion depth was measured and compared, the results are shown in FIG. Here, deposition depth difference (mm) is expressed by the following equation 3,

Depth Difference = ┃Target Depth-Actual Depth ┃ ‥‥‥‥ (3)

Marked as.

Referring to FIG. 6, in the conventional example in which the depth of deposition of the immersion nozzle was measured by the neck side or the actual measuring mechanism, the depth of deposition was 18 mm, whereas the depth of deposition of the immersion nozzle was measured by a non-contact sensor according to the present invention. In the case, the deposition depth difference was observed between 3.2mm and 1.2mm.

In addition, referring to FIG. 7 which shows the steelmaking defect index in cast steel produced by the casting process, the steelmaking defect index is 7.2 in the conventional example in which the depth of deposition of the immersion nozzle is measured by the neck side or the actual measuring mechanism. In the case of measuring the deposition depth of the immersion nozzle by the non-contact sensor according to the present invention, it can be seen that the steelmaking defect indexes were 3.2 and 1.9. This results in a decrease in steelmaking defect index as the control accuracy of the immersion nozzle's deposition depth is improved.

These results indicate that as the immersion nozzle is deposited at the correct depth compared to the set point, the mold slag incorporation due to turbulence caused by the instability of the molten steel flow is reduced when the immersion nozzle is deposited too shallowly compared to the set point. We believe this is because the collection of inclusions due to overgrowth of initial coagulation cells has decreased due to excessive decrease.

The foregoing is merely illustrative of the preferred embodiments of the present invention, recognizing that those skilled in the art to which the present invention pertains may make modifications and changes to the present invention without departing from the spirit and gist of the invention as set forth in the appended claims. shall.

According to the present invention, by accurately calculating the deposition depth of the immersion nozzle in the mold by a non-contact detection method it is possible to improve the quality of the product produced by the playing process.

Claims (4)

A measurement target installed at a tundish provided with an immersion nozzle at the bottom; A non-contact distance measuring sensor measuring a distance from the measurement target; And a calculating means for calculating a depth at which the immersion nozzle is deposited in a mold by receiving the moving distance of the measurement target after measuring the distance from the measurement target by the distance measuring sensor. Depth Measuring Device. The method of claim 1, The non-contact distance measuring sensor is any one of an ultrasonic sensor, an optical sensor, an optical fiber sensor, an optical fiber sensor, an infrared sensor, a magnetic sensor, an ultraviolet sensor, a laser sensor. The method of claim 1, The calculating means is to calculate the depth of deposition of the immersion nozzle (d1) d1 = (D-Do)-K; Where D is the distance between the sensor and the target during continuous casting, Do is the distance between the sensor and the target before continuous casting, and K is the hot water surface of the molten steel in the mold and before continuous casting. Immersion depth measurement device of the immersion nozzle, characterized in that the distance between the upper end of the molten steel discharge port of the immersion nozzle. The method of claim 1, Contact sensing means provided at an upper end of the mold; And further comprising a monitoring means for providing contact data between the contact sensing means and the immersion nozzle, and receiving the moving distance of the measurement target measured by the distance measuring sensor after the contact data is provided by the monitoring means. Depth depth measurement device of the immersion nozzle, characterized in that it comprises a calculation means for calculating the depth deposited on.

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