JP2012137309A - Control method of immersion depth of molten metal measuring probe, and molten metal measuring probe used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method of an immersion depth of a molten metal measuring probe capable of surely performing measurements, for example, a molten temperature, a solidification temperature, and sample properties by precisely controlling the immersion depth in a molten metal layer.SOLUTION: Detecting means 2 that detects the surface Ls of a molten metal layer L in a process of immersing a probe distal end 1a into a molten metal container is provided. The control method of the immersion depth comprises: based on a detecting signal of the molten metal layer surface Ls output from the detecting means 2 in an immersing step of the probe 1, controlling a subsequent immersion depth of the probe 1 in the molten metal layer L in the immersing step; calculating a lowering distance (an immersion amount) thereafter at a time point when the immersion depth in the molten metal layer in a charge reaches the molten metal layer surface Ls; and controlling and setting the immersion depth in real time.

Description

  The present invention relates to a method for controlling the immersion depth of a probe for measuring a molten metal that is preferably used in a converter or the like, and a probe for measuring a molten metal used therefor.

  In order to measure the temperature, solidification temperature, sample properties, etc. of the molten metal in a vessel such as a converter, a molten metal measuring probe having various sensors and a sample sampling port is used. In order to reliably perform various measurements and sample collection with this probe, it is necessary to control the depth at which the probe is immersed in the molten metal to a predetermined depth. In order to control the probe immersion depth, it is necessary to grasp the surface level of the molten metal layer. Various methods for measuring the surface level of the molten metal layer using a molten metal measuring probe have been proposed (see, for example, Patent Documents 1 to 4).

  However, all of the conventional measuring methods use the process of immersing the probe for measuring molten metal, but use the obtained surface level information in the next charge (purification process). Therefore, when the amount of the molten metal fluctuates in the next charge, the immersion depth also changes accordingly, and it is unavoidable that a slight deviation occurs in the accuracy of the immersion depth.

Japanese Patent Laid-Open No. 2004-125 566 JP 2002-356709 A JP-A-9-113333 Japanese Patent Laid-Open No. 10-122934

  Therefore, in view of the above-mentioned situation, the present invention intends to solve the problem by measuring the molten steel temperature, the solidification temperature, the sample properties, etc. more reliably by controlling the immersion depth in the molten metal layer more accurately. It is in the point which provides the immersion depth control method of the probe for a molten metal measurement which can be performed to this, and the probe for a molten metal measurement used for this.

  The present invention is a method for controlling the depth at which a molten metal measurement probe is immersed in order to solve the above-mentioned problems, and the probe is immersed in a molten metal container at the tip of the molten metal measurement probe. A detection means for detecting the surface of the molten metal layer is provided in the course of the process, and based on a detection signal of the surface of the molten metal layer output from the detection means in the process of the probe immersion, A method for controlling the immersion depth of a probe for measuring a molten metal is provided, wherein the immersion depth of the probe is controlled.

  Here, it is preferable that an electrode is provided at the tip of the molten metal measurement probe as the detection means in an externally exposed state, and the surface of the molten metal layer is detected based on a change in electrical characteristics through the electrode. ).

  In particular, the electrical characteristics between the electrode containing the molten metal and the conductive container and the electrode are monitored, and the electrical characteristics between the electrode and the container are such that the electrode contacts the surface of the molten metal layer. It is preferable to detect the point of time when the molten metal layer shifts to conductivity due to the inclusion of the molten metal layer.

  Furthermore, since the slag layer floats on the surface of the molten metal layer, the electrical characteristics between the electrode and the container are from the power generation property due to the interposition of the slag layer in which the electrode functions as an electrolyte in the slag layer. It is preferable to detect a point in time at which the transition to conductivity due to the presence of the molten metal layer occurs when contacting the surface of the molten metal layer.

  Specifically, the electrode is preferably provided along the outer peripheral surface of a paper cap that covers the sensor at the tip of the probe.

  Further, based on the detection signal of the surface of the molten metal layer outputted from the detection means in the probe immersion process and the speed information for lowering the probe, the probe into the molten metal layer in the subsequent immersion process It is preferable to control the immersion depth.

  The present invention also provides a probe for measuring a molten metal used in the immersion depth control method, wherein a detection means for detecting the surface of the molten metal layer in the process of immersing the probe in the molten metal container is provided at the tip. There is also provided a probe for measuring a molten metal, which is provided.

  Further, as the detection means, an electrode is preferably provided at the tip of the molten metal measurement probe in an externally exposed state, and the surface of the molten metal layer is detected based on a change in electrical characteristics through the electrode. 8).

  Further, it is preferable that the electrode is provided along the outer peripheral surface of a paper cap that covers the sensor at the tip of the probe.

  According to the method for controlling the immersion depth of the probe for measuring molten metal according to claim 1, based on the detection signal of the surface of the molten metal layer output from the detection means during the probe immersion process, the subsequent molten metal in the immersion process Since the immersion depth of the probe in the layer is controlled, the immersion depth is controlled in real time based on the level measurement in the same immersion process with the same charge. Depth of the depth does not occur, so that the immersion depth can be controlled more accurately, and measurements such as molten steel temperature, solidification temperature, and sample properties can be more reliably performed.

  According to the method for controlling the immersion depth of the molten metal measurement probe according to claim 2, an electrode is provided at the tip of the molten metal measurement probe as the detection means in an externally exposed state, and electrical characteristics through the electrode are controlled. Since the surface of the molten metal layer is detected based on the change, it can be detected instantaneously when the electrode reaches the surface of the molten metal layer, and the subsequent immersion depth can be controlled in real time based on the detection.

  According to the method for controlling the immersion depth of the probe for measuring a molten metal according to claim 3, the electrical characteristics between the container containing the molten metal and having conductivity and the electrode are monitored. Since the electrical characteristics between the containers are detected when the electrode is brought into conductivity due to the presence of the molten metal layer when the electrode contacts the surface of the molten metal layer, the detection reaches the surface of the molten metal layer. It is possible to instantly detect the time point, and based on that, the subsequent immersion depth can be controlled in real time.

  According to the method for controlling the immersion depth of the probe for measuring a molten metal according to claim 4, the slag layer is suspended on the surface of the molten metal layer, and the electrical characteristics between the electrode and the container indicate that the electrode is the slag layer. In this case, it is detected at the time when the electrode shifts from the power generation property due to the interposition of the slag layer functioning as an electrolyte to the conductivity due to the interposition of the molten metal layer when the electrode contacts the surface of the molten metal layer. Even when a layer is present, it is possible to instantly detect when the molten metal layer surface is reached, and to control the subsequent immersion depth in real time.

  According to the method for controlling the immersion depth of the molten metal measurement probe according to claim 5, since the electrode is provided along the outer peripheral surface of the paper cap that covers the sensor at the tip of the probe, until the paper cap is melted. There is no time difference, and when the electrode on the outer peripheral surface reaches the surface of the molten metal layer, it can be detected instantaneously, and the subsequent immersion depth can be controlled in real time based on this.

  According to the method for controlling the immersion depth of the probe for measuring molten metal according to claim 6, the detection signal of the surface of the molten metal layer output from the detection means in the process of the probe immersion, the speed information for lowering the probe, Therefore, the depth of immersion of the probe into the molten metal layer in the immersion process is controlled based on the above, so after the surface detection, the amount of immersion from there is calculated in relation to the speed, and how much time It is possible to grasp in real time whether to descend, and to easily control the amount of descending by time.

  According to the probe for measuring a molten metal according to the seventh aspect of the invention, since the tip portion is provided with the detecting means for detecting the surface of the molten metal layer in the process of immersing the probe in the molten metal container, In the same immersion process, the immersion depth is controlled in real time based on the level measurement, and there is no deviation of the immersion depth due to fluctuations in the amount of molten metal as before, so the immersion depth is more accurately controlled. It is possible to measure the molten steel temperature, solidification temperature, sample properties, etc. more reliably.

  According to the molten metal measuring probe according to claim 8, an electrode is externally exposed at the tip of the molten metal measuring probe as the detection means, and the molten metal layer is formed based on a change in electrical characteristics through the electrode. Since the surface is detected, it can be detected instantaneously when the electrode reaches the surface of the molten metal layer, and the subsequent immersion depth can be controlled in real time based on the detection.

  According to the molten metal measuring probe according to claim 9, since the electrode is provided along the outer peripheral surface of the paper cap that covers the sensor at the probe tip, there is no time difference until the paper cap melts, and the outer peripheral surface. When the electrode reaches the surface of the molten metal layer, it can be detected instantaneously, and the subsequent immersion depth can be controlled in real time based on this.

Explanatory drawing which shows the immersion depth control method of the probe for a molten metal measurement which concerns on typical embodiment of this invention. Explanatory drawing which similarly shows the front-end | tip part of the probe for a molten metal measurement. Explanatory drawing which shows the modification of the probe for a molten metal measurement. Explanatory drawing which shows the other modification of the probe for molten metal measurement.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  The method for controlling the immersion depth of the probe for measuring molten metal according to the present invention, as shown in FIG. 1, melts in the process of immersing the probe in the molten metal container at the tip 1a of the probe 1 for measuring molten metal. The detecting means 2 for detecting the surface Ls of the metal layer L is provided. Based on the detection signal of the molten metal layer surface Ls output from the detecting means 2 during the immersion process of the probe 1, the subsequent steps in the immersion process are performed. The immersion depth of the probe 1 in the molten metal layer L is controlled. Accordingly, for example, when the molten metal measuring probe 1 is lowered from the upper side to the lower side of the molten metal container C, the immersion depth in the molten metal layer L in the charge is determined in real time, that is, the surface of the molten metal layer. When reaching Ls, the subsequent descending amount (immersion amount) can be calculated and controlled and set in real time.

  In the conventional detection means, the electrode is embedded in the contents such as a paper cap, and the position of the surface of the molten metal layer is memorized at the time of ascending by using the electrode melted and exposed by the molten metal layer. The immersion depth is set based on the stored information on the assumption that it is a position. In this example, the initial stage of the immersion process in the same charge, that is, the stage where the surface Ls of the molten metal layer L is reached. In addition to detecting that the surface has been reached, the amount of immersion in the molten metal layer L is calculated from there, and it is possible to grasp in real time how much the probe 1 is further lowered and to control the amount of lowering. is there. Therefore, the probe immersion amount that accurately reflects the state of the molten metal in the charge can be set, and various measurements and sample collection by the molten metal measuring probe 1 can be performed accurately and reliably.

  The molten metal container C can be applied to a converter or ladle that contains molten steel as molten metal, but can also be applied to other molten metal containers. In the following embodiment, although the example applied to the blowing process in a converter is shown, it is not limited to this. Reference numeral 3 is a sub lance for supporting the probe, 4 is a sub lance lifting device for raising and lowering the sub lance, 5 is a sub lance operation control unit, and 6 is a main lance for blowing oxygen from the tip to the molten steel below.

  The molten metal measuring probe 1 basically has the same basic structure as various conventionally known probes, and further includes detection means 2 for detecting the surface of the molten metal layer. As shown in FIG. 2, the probe 1 of this example has an oxygen sensor 11, a correction electrode 12, and a temperature sensor 13 fixed to the tip 1 a with heat-resistant cement as shown in FIG. 2, and these are covered with a paper cap 10. A sample collection port 14 is provided in the body of the probe 1 and is closed with a paper exterior member. When such a probe 1 is immersed to a predetermined depth position of the molten metal layer L, the paper cap 10 and the exterior member are melted and disappeared by the high-temperature molten metal, the sensor is exposed, and the molten metal is exposed at the position. In addition to performing various measurements, the molten metal is taken from the sample collection port 14 and used for measurement of the solidification temperature and the like.

  The molten metal measuring probe 1 is immersed in the converter C by a sublance 3 as shown in FIG. Specifically, a molten metal measuring probe 1 is attached to the lower end portion of a sublance 3 disposed in the vertical direction above the converter C, and the sublance 3 is moved up and down by the sublance lifting device 4 together with the probe 1. The probe 1 can be moved up and down inside the converter C. As a result, the probe 1 is immersed in the molten metal layer L through the slag layer B floating on the surface of the molten metal from the atmospheric layer A, stopped at a predetermined depth for several seconds, and measured by various sensors and sampled. After that, the molten metal layer L is pulled up to the atmosphere layer A through the slag layer B. The sublance lifting / lowering device 4 is configured using a servo motor, a pulse motor, or the like, and is controlled by the sublance operation control unit 5. Furthermore, in this example, the sub lance lifting / lowering device 4 is provided with a rotary encoder to grasp the vertical movement distance of the sub lance 3.

  The converter C is formed by stacking refractory bricks inside a metal container, and the container itself is grounded to the ground. The converter alone does not have conductivity, but by containing molten steel in the converter, metal adheres to the inner surface of the converter, and the space between the inner surface of the converter and the ground has conductivity. That is, it is equivalent to the converter being grounded to the ground.

  The detection means 2 of the probe 1 for measuring a molten metal is provided with an electrode 20 in an externally exposed state along the outer peripheral surface of a paper cap 10 that covers the above-described sensors 11 and 13 of the probe tip 1a. Similar to the oxygen sensor 11, the correction electrode 12, and the temperature sensor 13, the lead wire of the electrode 20 is extended to the base end side along the probe 1, and is connected to the wiring in the sub lance 3 through a connector (not shown). The wiring is connected to the sub lance operation control unit 5.

  Hereinafter, a method for controlling the immersion depth of the molten metal measurement probe 1 will be described.

  The probe 1 is immersed in the converter C together with the sublance 3. The probe 1 is first inserted into the slag layer B floating on the molten metal surface from the atmospheric layer A. The converter C is connected to the ground, and the time when the electrical characteristics between the electrode 20 at the tip of the probe and the converter C shift from the insulation of the atmospheric layer A to the power generation of the slag layer B, The surface position of the slag layer B is detected and the position is stored. Furthermore, the surface Ls of the molten metal layer is detected by lowering the slag layer B and capturing the point that the electrical characteristics between the electrode 20 and the converter C have shifted from the power generation property to the conductivity of the molten metal layer L. , Remember its position.

  From the surface position of the molten metal layer and the surface position of the slag layer B described above, the thickness of the slag layer B can be calculated. The storage of the surface position of the slag layer B and the calculation of the thickness of the slag layer B do not have to be performed when the probe 1 is lowered, and may be performed when the probe is raised after measurement by various sensors or sample collection. Moreover, when there is no slag layer like the case of a vacuum furnace, the point which shifted to the electroconductivity of a molten metal layer from the insulation of an atmospheric layer will be caught.

  Japanese Unexamined Patent Application Publication No. 2002-356709 and Japanese Unexamined Patent Application Publication No. 8-49024 can be referred to as a detection method for capturing a change in electrical characteristics. In JP-A-8-49024, two electrodes are provided on the probe side to determine conductivity. Also in the present application, two electrodes may be provided in this way to determine the conductivity between them. However, in this case, there is a risk of conducting a detection by splash or the like before reaching the surface of the molten metal layer, and erroneous detection. Therefore, it is more preferable to look at the electrical characteristics between the electrode and the container as in this example.

  Based on the detected information on the surface Ls of the molten metal layer, the sub lance operation control unit 5 calculates the immersion depth from the sub lance descent speed, and controls the subsequent descent operation of the sub lance. That is, the amount of immersion from the surface of the molten metal is calculated in relation to the speed, and it is possible to grasp in real time how much time is lowered, and the amount of decrease can be controlled by time. In addition to the method of controlling the descending amount from the descending speed as described above, the subsequent descending distance (immersion depth) can also be controlled by the rotation speed of the encoder.

  As described above, the probe 1 immersed in the molten metal layer L to a predetermined depth stops at the depth position, and measures the oxygen partial pressure and temperature by various sensors (reference numerals 11 to 13) and the sample collection port 14. After the sample is taken from the molten metal layer L, the molten metal layer L is pulled up to the atmosphere layer A through the slag layer B.

  FIG. 3 shows an example in which a coil-type level meter 21 that can measure the surface level of the molten metal layer without contact is provided inside the paper cap 10 of the tip 1a of the probe 1 for measuring molten metal. This is to detect the fluctuation of the magnetic field due to the approach of the surface of the molten metal layer and to detect the surface level. Since it can be detected in a non-contact manner, it can be mounted in the paper cap 10 and should be detected by the exposed electrode 20 described above. Even in the case of detection, it can be verified whether or not the operation is normal by using this level meter 21 together, and erroneous detection can be prevented. FIG. 4 shows an example in which the detection means 2 is configured by only the coil type level meter 21 described in FIG. 3, and this is also possible. Furthermore, other known detection means 2 proposed in the past can be used.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can of course be implemented in various forms without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Molten metal measuring probe 1a Tip part 2 Detection means 3 Sublance 4 Sublance raising / lowering device 5 Sublance operation control part 6 Main lance 10 Paper cap 11 Oxygen sensor 12 Correction electrode 13 Temperature sensor 14 Sample sampling port 20 Electrode 21 Coil type level meter A Atmosphere layer B Slag layer C Container (converter)
L Molten metal layer (molten steel layer)
Ls surface

Claims (9)

A method for controlling the depth at which a probe for measuring a molten metal is immersed,
A detection means for detecting the surface of the molten metal layer in the process of immersing the probe in the molten metal container is provided at the tip of the probe for measuring the molten metal,
Based on the detection signal of the surface of the molten metal layer output from the detection means during the probe immersion process, the immersion depth of the probe in the molten metal layer in the subsequent immersion process is controlled. A method for controlling the immersion depth of a probe for measuring molten metal.   2. The immersion depth according to claim 1, wherein an electrode is provided at the tip of the molten metal measurement probe as the detection means in an externally exposed state, and the surface of the molten metal layer is detected based on a change in electrical characteristics through the electrode. Control method.   The electrical property between the electrode containing the molten metal and the conductive container and the electrode is monitored, and the electrical property between the electrode and the container is determined when the electrode contacts the surface of the molten metal layer. The immersion depth control method according to claim 2, wherein a time point at which transition to conductivity is detected due to the presence of the molten metal layer is detected.   A slag layer floats on the surface of the molten metal layer, and the electrical characteristics between the electrode and the container are from the power generation property due to the interposition of the slag layer in which the electrode functions as an electrolyte in the slag layer. The immersion depth control method according to claim 3, wherein the immersion depth control method is formed by detecting a time point when the molten metal layer is brought into conductivity due to the presence of the molten metal layer when contacting the surface of the molten metal layer.   The immersion depth control method according to any one of claims 2 to 4, wherein the electrode is provided along an outer peripheral surface of a paper cap that covers a sensor at a probe tip.   Based on the detection signal of the surface of the molten metal layer output from the detection means in the course of the probe immersion and the speed information for lowering the probe, the probe is subsequently immersed in the molten metal layer in the immersion process. The depth is controlled, The immersion depth control method according to claim 1, wherein the depth is controlled.   It is a probe for a molten metal measurement used for the immersion depth control method of any one of Claims 1-6, Comprising: Molten metal layer in the process in which this probe is immersed in a molten metal container at the front-end | tip part A probe for measuring a molten metal, comprising a detecting means for detecting a surface.   The molten metal measurement according to claim 7, wherein an electrode is externally exposed at the tip of the molten metal measurement probe as the detection means, and the surface of the molten metal layer is detected based on a change in electrical characteristics through the electrode. Probe.   The molten metal measuring probe according to claim 8, wherein the electrode is provided along an outer peripheral surface of a paper cap that covers a sensor at a tip portion of the probe.

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