KR20040028284A - Monitoring method of dip condition of shroud nozzle in continuous casting machine - Google Patents

Abstract

PURPOSE: A method for monitoring the dipping state of ladle shroud nozzle of continuous casting machine is provided to monitor reoxidation of molten steel in real time and help control quality class by checking whether a lower part of shroud nozzle is dipped into molten steel of tundish and automatically monitoring dipping depth of the shroud nozzle. CONSTITUTION: The method comprises first step of proceeding a screen display step by judging that shroud nozzle is not dipped into molten steel in tundish if it is not the interlocking mode by judging whether it is a shroud device interlocking mode or not if continuous casting machine is operated, and proceeding the next step if it is the interlocking mode; second step of detecting the measured values by measuring detection values of ladle height, detection values of height of molten steel in tundish and detection values of ascending height of tundish respectively; third step of calculating dipping depth of the shroud nozzle according to standard values including preset standard ladle height value, standard shroud nozzle value, standard height value of molten steel in tundish and standard ascending position value of tundish and detection values including the measured detection values of ladle height, detection values of height of molten steel in tundish and detection values of ascending height of tundish; fourth step of judging whether the shroud nozzle is dipped into tundish molten steel or not according to the calculated dipping depth of the shroud nozzle; and fifth step of displaying on a screen the calculated dipping depth of the shroud nozzle and information on whether the shroud nozzle is dipped into tundish molten steel or not.

Description

MONITORING METHOD OF DIP CONDITION OF SHROUD NOZZLE IN CONTINUOUS CASTING MACHINE}

The present invention relates to a method for monitoring the ladle shroud nozzle deposition state of a continuous casting machine. In particular, the lower end of the shroud nozzle for supplying the molten steel of the continuous address machine to the tundish without contact with air is deposited on the tundish molten steel. Ladle shroud nozzles of continuous casting machines that can automatically monitor molten steel refinancing in real time by providing automatic measurement of the presence and depth of deposition and thus providing real-time monitoring of molten steel reoxidation. The present invention relates to a method for monitoring deposition status.

In general, in the continuous addressing machine, the molten steel of the ladle is provided as a tundish, and the molten steel of the tundish is discharged to the lower side, and the steel sheet is addressed. It is a well-known fact, and it must be possible to prevent the reoxidation of such molten steel to maintain the quality of the steel sheet produced above a certain level. There are a number of factors related to quality, but the factors caused by contact with air generated in tundish are one of the factors that affect quality.

In order to prevent reoxidation of such molten steel, conventionally, a shroud nozzle is provided at the bottom of the ladle bottom molten steel outlet for providing molten steel from the ladle to the tundish, and the molten steel is supplied to the tundish from the ladle. In order to prevent contact with the air during the lower end of the shroud nozzle is preferably deposited in the molten steel of the tundish.

If molten steel is exposed to air in the tundish 30 in the continuous casting operation and reoxidation occurs, it is included in the quality determination and the quality grade is lowered or the slab care code is assigned to perform secondary correction. shall.

However, conventionally, there was no method of checking whether the shroud nozzle was immersed and the depth of deposition during casting, and the method of determining whether the molten steel is exposed to the air is dependent on the naked eyes of the operator. There was a problem that there was a problem, there was a difficulty and inconvenience in real-time molten steel reconstruction, and there was a problem that quality control could not be properly performed.

The present invention has been made to solve the above problems, an object of the present invention is the lower end of the shroud nozzle for supplying the molten steel of the ladle of the continuous addresser to the tundish without contact with air, deposited in the tundish molten steel Ladle shroud nozzles of continuous casting machines that can automatically monitor molten steel refinancing in real time by providing automatic measurement of the presence and depth of deposition and thus providing real-time monitoring of molten steel reoxidation. The present invention provides a method for monitoring deposition conditions.

1 is a block diagram of a ladle shroud nozzle deposition state monitoring apparatus of a continuous casting machine for carrying out the present invention.

2 is a flowchart showing a ladle shroud nozzle deposition state monitoring method of a continuous casting machine according to the present invention.

3A is a tundish molten steel injection state diagram when no shroud nozzle is used.

Figure 3b is an example of microscopic openings in the case of using the shroud nozzle.

Figure 3c is an exemplary view of immersion opening in the case of using the shroud nozzle.

Figure 4a, 4b is an exemplary view showing a method of calculating the molten steel of the tundish according to the present invention.

Explanation of symbols on the main parts of the drawings

10: Ladle 11: Ladle Height Gauge (LVDT)

12: ladle slide gate 20: shroud device

21: Shroud Nozzle 30: Tundish

31: Tundish height measuring instrument (Encoder) 32: Tundish molten steel

33: tundish molten steel insulation / oxidation prevention material 40: mold

50: continuous casting machine control unit 110: key input / control unit

120: control unit 130: screen display unit

As a technical means for achieving the above object of the present invention, a feature of the present invention is to install a shroud nozzle to perform the molten steel discharge pipe function in the molten steel outlet of the lower ladle to provide molten steel in the ladle of the continuous casting machine, In the ladle shroud nozzle deposition state monitoring method for monitoring whether the lower end of the shroud nozzle is deposited in the molten steel of the tundish while the molten steel is supplied to the tundish in the ladle, when the continuous casting machine is operated, the shroud device interlocked A first step of determining whether the mode is in the interlocked mode, and if not in the interlocked mode, proceeds to the screen display step and proceeds to the next step in the interlocked mode; A second step of measuring and detecting a ladle height detection value, a tundish molten metal height detection value, and a tundish rise height detection value, respectively; A reference value including a preset ladle height reference value, a shroud nozzle reference value, a tundish molten metal height reference value and a tundish rising position reference value, the measured ladle height detection value, a tundish molten steel height detection value and a tundish rising height detection value Calculating a depth of deposition of the shroud nozzle according to a detection value comprising a; A fourth step of determining whether to deposit according to the calculated deposition depth; And a fifth step of displaying the calculated depth and deposition information on the screen. To provide a ladle shroud nozzle deposition state monitoring method of a continuous casting machine characterized in that it comprises a.

Hereinafter, the configuration and operation of the ladle shroud nozzle deposition state monitoring apparatus of a continuous casting machine for carrying out the present invention will be described in detail. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

1 is a configuration diagram of a ladle shroud nozzle deposition state monitoring apparatus of a continuous casting machine for carrying out the present invention, referring to Figure 1, ladle shroud nozzle deposition state monitoring apparatus of a continuous casting machine for carrying out the present invention is continuous Continuous casting machine controller 50 which controls the related equipment of the casting machine, namely ladle operation, ladle slide gate operation, shroud device operation, etc., and inputs command of setting reference value and operation command for ladle shroud nozzle deposition status And a key input / operation unit 110 for operation, a ladle height measuring device 12 (LVDT) for measuring the rise and fall height of the ladle 10, and the rise and fall height of the tundish 30. The tundish height measuring device 31 (Encoder) for measuring the tundish according to the reference value input through the key input / operation unit 110 and the detection value measured by the measuring device (12,31) On molten steel A control unit 120, a screen display 130 that displays the height and the immersion deposition or failure information on the screen under the control of the controller 120 that performs whether or not the immersion height calculation and determination of the immersion nozzle loud.

The control unit 120 includes a program that receives data from the measuring device and calculates it. The control unit 120 uses the reference data (1) inputted by the driver and facility status and location (2) data to determine whether or not to deposit and open the deposition depth. The program to calculate is pre-installed.

2 is a flowchart showing a ladle shroud nozzle deposition state monitoring method of a continuous casting machine according to the present invention, Figure 3a is a tundish molten steel injection state diagram when the shroud nozzle is not used, Figure 3b is to use the shroud nozzle It is an illustration of the microscopic opening in a case. And, Figure 3c is an exemplary view of the immersion opening in the shroud nozzle when used, Figures 4a, 4b is an illustration of the method of calculating the molten steel height of the tundish according to the present invention.

Operation of the preferred embodiment of the present invention configured as described above will be described in detail below based on the accompanying drawings.

The present invention provides a shroud nozzle 21 for performing the molten steel discharge pipe function in the ladle bottom molten steel outlet for providing molten steel from the ladle 10 of the continuous casting machine to the tundish 30, the molten steel in the ladle 10 A method of monitoring the deposition state of the ladle shroud nozzle 21 that monitors whether the lower end of the shroud nozzle 21 is deposited on the molten steel of the tundish 30 while being supplied to the tundish 30, that is, continuously In a continuous casting machine, the molten steel in the ladle 10 is utilized by utilizing a ladle height measuring device LVDT and a tundish height measuring device Encoder. In injection into the tundish 30, a shroud nozzle 21 is used to prevent reoxidation due to molten steel being in contact with air. The molten steel in the ladle 10 is turned. The shroud nozzle 21 (Shroud Nozzle) is immersed in the tundish molten steel 32 at the time when the first injection into the dish 30 begins. Automatically detects whether the system is in operation and deposits the shroud nozzle 21 (Shroud Nozzle) deposited on the tundish molten steel 32 during the casting operation (in the control mode of the shroud device 20). By automatically checking (calculating) the depth, it is possible to monitor the deposition opening and the molten steel regeneration according to the depth of deposition.

Here, if defined for the terms used in the present invention, the immersion opening is a shroud nozzle 21 (Shroud Nozzle) to start the first injection of the molten steel in the ladle 10 (Ladle) to the tundish 30 (Tundish) The shroud nozzle 21 (Shroud Nozzle) is defined as being opened in the state of being deposited in the tundish molten steel 32 at the time point, and the depth of the shroud nozzle 21 (Shroud Nozzle) is a tundish molten steel ( It is defined as the depth deposited in 32).

Referring to Figures 1 to 3c in more detail, first, in the first step (S21-S23) is determined to start the operation of the continuous casting machine based on the operation start signal from the continuous casting machine operation control device 50, If it is determined that the shroud device is in the interlocking mode, if it is not the interlocking mode, it is judged inferiorly and proceeds to the screen display step.

Next, in the second step S24-S26, the ladle height detection value HLP by the ladle height measuring device 12, the molten steel supply amount from the ladle to the tundish and the tundish molten steel height detection value based on the tundish volume ( HTMD) and the tundish rise height detection value HTPD by the tundish height measuring device 31 are respectively measured and detected.

Next, in the third step (S27, S28), the control unit 120 is a preset ladle height reference value (HLR), shroud nozzle reference value (HSR), tundish molten steel height reference value (HTMR) previously set through the key input / operation unit (110) And a reference value including a tundish ascending position reference value (HTPR), the measured ladle height detection value (HLP), a tundish molten steel height detection value (HTMD) and a tundish ascent height detection value (HTPD). The depth of deposit (D) of the shroud nozzle is calculated according to the value.

The reference value is a value previously set through the key input / operation unit 110, which is a tundish weight, ladle lifting position, tundish lifting position, and shroud. There is a Nozzle Length (Long Nozzle), where the amount of tumbledish molten steel is again calculated as the height of the molten steel in the tundish according to the preset contents of the tundish and the amount of molten steel supplied. 4A and 4B, depending on the form of the content of the tundish, the content of the tundish may not be proportional to the height, or the content of the tundish increases proportionally with the height. There is a case. In each of these cases, a molten steel height reference value corresponding to the content of the applied tundish is set, and based on the molten steel height reference value and the supplied molten steel amount, the height of the molten steel stored in the current tundish can be known.

Thereafter, the ladle 10 arrives at the casting position by the continuous casting machine operation control device 50 and at the moment when the ladle slide gate 11 is opened to inject molten steel of the ladle 10 into the tundish 30. When the shroud device 20 ascends and descends the ladle, at the same time, it is confirmed that the tandem mode is selected to interlock with the ladle 10. If the shroud device 20 is not the interlocked mode, the shroud nozzle 21 (Shroud) It is determined that the nozzle is not used (FIG. 3A), and it turns out to be a non-invasive opening, and in the case of the tandem mode, it is determined that the shroud nozzle 21 (Shroud nozzle) is used, and the reference value and the detected value are It is calculated by calculating the depth of deposition (D).

In detailing the calculation of the deposition depth D in the third steps S27 and S28, the ladle height value is obtained by subtracting the ladle height detection value HLD detected by the preset ladle rising position reference value HLR. (LP), subtract the constant value set from the preset shroud nozzle reference value (HSR) to obtain the shroud nozzle value (SP), and the turn detected from the preset tumble steel height reference value (HTMR). Subtract the dish molten steel height detection value (HTMD) to obtain the tundish molten steel height value (TM), and then turn off the tumble dish rising height detection value (HTPD) detected by the preset tundish rise height reference value (HTMR). Obtain the dish rising height value TP, add the shroud nozzle value SP to the ladle height value LP, and subtract the tundish molten steel height value TM and the tundish rising height value TP to rest. Calculate the deposition height (D) of the wood nozzle. This calculation method is expressed by Equation 1 below.

Depth of Deposition (D)

= ((Laddle Lift Position Reference Value (HLR)-Ladle Lift Value (HLD) (LP))

+ (Shore Nozzle Threshold (HSR)-1370) (SP)

+ (-(Tundish Molten Height Reference Value (HTMR)-Tundish Molten Height) (HTMD) (TM))

+ (-(Tundish Up Position Reference Value (HTPR)-Tundish Up Position (HTPD)) (TP))]

Then, in the fourth step (S29), it is determined whether or not to deposit according to the calculated depth of deposition (D), if the calculated value is output as a (+) value is determined as the hole opening (Fig. 3b), while If it is output as a negative value, it is judged as a non-invasive opening (FIG. 3C). In the fourth step (S28), if the calculated deposition height (D) is greater than zero (ZERO), it is determined to be a deposition opening, and if the calculated deposition height (D) is less than zero (ZERO), it is determined as a non-deposition opening. do. Then, it is stored in the operation database. Subsequent calculations are then sent to the operating database for deposition depth and stored.

Further, in the fifth step (S30, S31), the calculated depth of deposition (D) and whether or not the information is displayed on the screen through the screen display unit 130, where the shroud nozzle (21) even during unopened opening or casting operation When the depth of deposition of the shroud nozzle is negative, the quality grade can be automatically lowered according to the steel grade or the slab care code can be automatically assigned to lead to the later process. Sedimentation openings and depth data stored in the operations database can be used to analyze the cause of quality defects.

According to the present invention as described above, it is possible to monitor the molten steel in contact with the air and immediately use it for quality grade determination online. In addition, it was used to analyze the cause of defects when quality defects occurred, so that the degree of quality deterioration due to the depth of deposition and undestructive opening could be identified.

According to the present invention as described above, it is possible to monitor the molten steel in contact with the air in the tundish, which is immediately used for quality grade determination online. In addition, it was used to analyze the cause of defects when quality defects occurred, so that the degree of quality deterioration due to the depth of deposition and undestructive opening could be identified.

In addition, whether or not deposition was necessary to identify the quality deterioration factors and the cause analysis could not be performed because there was no deposition depth data at each casting location. The calculation results are stored in the operation database so that the cause of quality defects can be identified.

The above description is only a description of specific embodiments of the present invention, and the present invention is not limited to these specific embodiments, and various changes and modifications of the configuration are possible from the above-described specific embodiments of the present invention. It will be apparent to those skilled in the art to which the present invention pertains.

Claims (3)

In the ladle of the continuous casting machine, a shroud nozzle serving as a molten steel discharge pipe is installed at the lower molten steel outlet of the ladle to provide molten steel to the tundish, and the lower portion of the shroud nozzle is supplied to the tundish while the molten steel is supplied from the ladle to the tundish. In the ladle shroud nozzle deposition state monitoring method for monitoring whether it is deposited in molten steel, When the continuous casting machine is operated, it is determined whether the device is in the shroud device interworking mode. If the interlocking mode is not in the interlocking mode, the first process proceeds to the screen display step and in the interlocking mode, the first step (S21). -S23); A second step (S24-S26) of measuring and detecting a ladle height detection value HLP, a tundish molten metal height detection value HTMD, and a tundish rise height detection value HTPD, respectively; A reference value including a preset ladle height reference value (HLR), a shroud nozzle reference value (HSR), a tundish molten steel reference value (HTMR) and a tundish ascending position reference value (HTPR), and the measured ladle height detection value (HLP A third step (S27, S28) of calculating the depth of deposition (D) of the shroud nozzle according to the detected value including the tundish molten steel height detection value (HTMD) and the tundish rise height detection value (HTPD); A fourth step (S29) of determining whether to deposit according to the calculated deposition depth (D); And A fifth step (S30, S31) of displaying the calculated deposition depth (D) and deposition information on the screen; Ladle shroud nozzle deposition state monitoring method of a continuous casting machine characterized in that it comprises a. The method of claim 1, wherein the third steps S27 and S28 are performed. The ladle height value LP is obtained by subtracting the ladle height detection value HLD detected from the ladle rising position reference value HLR set in advance. Obtain the shroud nozzle value (SP) by subtracting the set constant value from the preset shroud nozzle reference value (HSR), The tundish molten steel height value TM is obtained by subtracting the tundish molten metal height detected value HTMD detected from the preset tundish molten steel height reference value HTMR, The tundish rise height value TP is obtained by subtracting the tundish rise height detection value HTPD detected from a preset tundish rise height reference value HTMR, The shroud nozzle value SP is added to the ladle height value LP, and the deposition height D of the shroud nozzle is calculated by subtracting the tundish molten steel height value TM and the tundish rising height value TP. Ladle shroud nozzle deposition state monitoring method of a continuous casting machine characterized in that the. The method of claim 1, wherein the fourth step (S29) If the calculated deposition height (D) is greater than zero (ZERO) it is determined as the deposition opening, Ladle shroud nozzle immersion state monitoring method of the continuous casting machine, characterized in that it is determined as the undetermined opening if the calculated deposition height (D) is less than zero (ZERO).