JP4359277B2 - Nozzle refractory thickness reduction measuring device - Google Patents

Description

  The present invention relates to a thickness reduction measuring device for measuring a thickness reduction amount of a nozzle refractory attached to a ladle or a tundish hot.

  Conventionally, a ladle is used when temporarily storing molten steel melted and refined in a converter or electric furnace and transporting it to, for example, a continuous casting facility. The molten steel stored in the ladle is injected into the mold through the upper nozzle arranged in the ladle and the lower nozzle suspended from the bottom of the ladle by opening the slide plate provided at the bottom. It has become.

  The upper nozzle is usually composed of a refractory molded into a cylindrical shape, but the molten steel is washed with oxygen to remove foreign matter after the molten steel flows at a high pressure in the cylindrical hole or after the molten steel is discharged. As a result, the thickness of the nozzle gradually decreases.

  If the thickness reduction is increased in the upper nozzle, the molten steel flow in the upper nozzle may be disturbed, and the injection time may change, affecting the product quality. It needs to be replaced accordingly.

  However, the degree of thickness reduction of the upper nozzle is confirmed by a skilled person visually, or a known thickness is inserted into the upper nozzle to estimate the amount of thickness reduction. However, there is a problem that the amount of thickness reduction of the upper nozzle, which is not necessarily reduced, cannot be accurately grasped.

In addition, as a method of calculating the damage position and damage amount of the refractory, acoustic sensors are arranged at a plurality of locations on the outer surface of the converter, the acoustic signals generated by scrap in the furnace are detected, and the acoustic signals and the positions of the acoustic sensors are detected. A management method for calculating the damage position and the damage amount of the refractory from the relationship has also been proposed (see, for example, Patent Document 1).
JP-A-6-136426

  However, the above-described measurement method using an acoustic signal has a drawback that the measurement cannot be completed in a short time as the apparatus becomes complicated.

  Since the upper nozzle is made of refractory material, it is desirable to end the measurement in a short time during the heat in order to extend the service life, but the temperature around the ladle is still due to radiant heat even after the molten steel is discharged. It is hot and the working environment is harsh. In such a high-temperature and dangerous work environment, it cannot be put into practical use unless measurement can be completed in a short time.

  The present invention has been made in consideration of the problems in the conventional method for measuring the thickness reduction of the upper nozzle as described above, and it is possible to measure the thickness reduction of the nozzle refractory hot and in a short time. The present invention provides a device for measuring the amount of thickness reduction of a nozzle refractory.

  The present invention is a nozzle thickness reduction measuring device for measuring the thickness reduction of a nozzle-like refractory attached to a steel receiving container such as a ladle or tundish, and an outer hole formed in the steel receiving container. A main body part that has an engaging part that can engage with the peripheral edge part, and has a swing fulcrum on the main body part, and the front side of the swing fulcrum extends into the nozzle refractory and is rocked. On the rear side of the moving fulcrum, the swing arm that extends outside the steel receiving container, the contact portion that is provided at the tip of the swing arm and contacts the inner wall of the nozzle refractory, and the swing arm are positioned at the measurement reference position. Nozzle-shaped comprising a positioning portion for setting to a position and a swing amount detecting means for detecting a swing arm swing amount behind the swing support when the contact portion comes into contact with the inner wall of the nozzle-like refractory This is a refractory thickness reduction measuring device.

  As a specific example of the nozzle-like refractory according to the present invention, an upper nozzle of a sliding nozzle inserted into the ladle bottom is shown.

  In the present invention, the main body portion includes a cylindrical portion that is inserted into an exterior hole (for example, an iron hole), and a disc portion that is fixed to the rear end in the insertion direction of the cylindrical portion and is mounted on the exterior hole. it can.

  The gist of the present invention is that an annular step portion that engages with the entire periphery of the outer peripheral portion of the exterior hole is formed in the disc portion as the engaging portion.

  In the present invention, a viewing window for confirming the contact state between the contact portion and the nozzle-like refractory inner wall can be formed on the disk portion.

  In the present invention, the swing fulcrum of the swing arm is preferably pivotally supported by a bearing. Thereby, the swing arm can be swung without rattling, and as a result, the measurement accuracy can be improved.

  In the present invention, a dial gauge may be provided as the shake amount detecting means, and the measuring element may be configured to come into contact with the swing arm located behind the swing support point in the swing direction.

  According to the present invention, the thickness reduction amount of the nozzle-like refractory can be measured hot and in a short time.

  Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 shows a configuration of a refractory nozzle and a sliding nozzle including the refractory nozzle measured by a refractory nozzle thickness reduction measuring device (hereinafter abbreviated as a thickness reduction measuring device) of the present invention.

  In the same figure, 1 is a support bracket for supporting the bottom plate, 2 is an iron skin forming the exterior of the ladle bottom, 3 is a lower receiving tray arranged at the bottom of the ladle, and 4 is also an upper receiving brick. It is.

  5 is an upper nozzle (refractory nozzle) made of alumina carbon formed into a cone shape to be inserted into these receiving bricks, 6 is a bottom plate, 7 is a lower nozzle (changing nozzle) that moves with the slide plate, and 8 is molten steel. A slide plate 9 for opening and closing the flow path, 9 is a lower nozzle case.

  In the thickness reduction measuring device, the molten steel is discharged from the ladle, and the lower nozzle 7 and the slide plate 8 are removed from the ladle, and are attached to the iron hole 2a at the bottom of the ladle.

  2 to 4 show the configuration of the thickness reduction measuring device. FIG. 2 is a side view, FIG. 3 is a front view thereof, and FIG. 4 is a bottom view thereof. However, the ladle shows a state where the ladle is laid down in a horizontal posture, and in FIG. 2, the bottom iron skin 2 is arranged substantially vertically.

  First, in FIG. 2, the thickness reduction measuring device 10 includes a main body 11, a swing arm 12, a dial gauge 13 as a swing amount detecting means for detecting the swing amount of the swing arm, and a handle 14. It is mainly composed.

  The main body 11 has a cylindrical part 11a inserted into the cylindrical hole of the upper nozzle 5, and a disk part 11b connected to the rear end in the insertion direction (arrow A direction) of the cylindrical part 11a. The swing arm 12 passes through a through hole 11c as a viewing window drilled in the center of the plate portion 11b. The length L1 of the cylinder portion 11a in the cylinder axis direction is set to a length that does not drop off when the thickness reduction measuring device 10 is mounted in the upper nozzle 5, for example, about 100 mm.

  The main body 11 can be made of iron, but can be made of, for example, an aluminum alloy other than iron as long as it is a member that can withstand high temperatures during measurement and is not likely to be deformed.

  When the material of the main body 11 is made of an aluminum alloy, there is an advantage that it is excellent in portability because the weight can be reduced. In consideration of portability, it is preferable that the thickness of the thickness reduction measuring device 10 is 5 kg or less.

  The through hole 11c is also used for confirming the measurement site D, and the diameter L4 (see FIG. 3) of the opening is preferably formed in the range of 40 to 110 mm. If it is less than 40 mm, it cannot be confirmed that the protrusion (contact part) 12 b of the swing arm 12 is in contact with the measurement site D, and if it exceeds 110 mm, the thickness is reduced by radiant heat leaking from the inside of the ladle. This is because the measuring device 10 is damaged.

  Further, the outer diameter L2 (see FIG. 3) of the disc portion 11b is formed to be slightly larger than the hole diameter L3 of the iron shell 2 (more specifically, the support fitting), and the outer periphery of the iron shell 2 is formed on the outer peripheral portion thereof. An engaging portion 11d formed in a step shape is formed so as to engage with the entire periphery of the hole edge (peripheral portion) 2a. This engaging part 11d functions as a positioning means for positioning the position of the swing arm 12 at a fixed part when the thickness reduction measuring device 10 is inserted into the iron hole 2a.

  Next, the swing arm 12 and its mounting structure will be described.

  The swing arm 12 is obtained by processing an iron flat bar having a thickness of 6 mm, and a through hole 12a for inserting a pin to be described later is formed at a substantially center of gravity. The through-hole 12a serves as a swing fulcrum of the swing arm 12, the front side of the through-hole 12a (in the insertion direction of the cylindrical portion 11a) is tapered, and the tip functions as a contact. A triangular protrusion 12b is formed downward. The material of the swing arm 12 can be an aluminum alloy as in the case of the main body 11.

  The thickness of the swing arm 12 can be selected in the range of 5 to 10 mm. If it is less than 5 mm, the tip of the arm is deformed by heat. If it exceeds 10 mm, if the measurement site D is recessed, it cannot enter the recess and may cause a measurement error.

  The oscillating arm 12 can oscillate in the vertical direction with the oscillating fulcrum B as the center of rotation, and can theoretically oscillate to a range where it abuts on the tip edge 11e of the cylindrical portion 11a.

  FIG. 5 shows a mounting structure of the swing arm 12 and the disc portion 11b, where (a) shows the front and (b) shows the side.

  In both figures, a rectangular partition plate 11f is attached so as to partition the through hole 11c of the disc portion 11b in the diameter direction, and a slit 11h is formed in the partition plate 11f in parallel with the long side of the partition plate. Yes.

  In the longitudinal direction of the slit 11h, one groove edge 11i is located at the center of the partition plate 11f, and the other groove edge 11j is located near the end of the partition plate 11f.

  In addition, on one groove edge 11i, a horizontal surface 11k and a downwardly inclined surface 11l (see FIG. 5 (b)) communicating with the horizontal surface are formed.

  If the lower edge 12c of the swing arm 12 is brought into contact with the horizontal plane 11k, the posture of the swing arm 12 can be held horizontally, whereby the swing arm 12 can be held in the measurement reference line M shown in FIG. It can be adapted to. In addition, the inclined surface 11 l is provided to ensure a swing angle of the swing arm 12, and 11 m is a pin mounting hole penetrating the swing arm 12.

  FIG. 6 is an enlarged plan view of the swing fulcrum portion of the swing arm 12.

  In the figure, a swing arm 12 is inserted through a slit 11h of a partition plate 11f, a pin 15 is inserted into a through hole 12a of the swing arm 12, and a spherical surface is formed in a gap between the outer peripheral surface of the pin 15 and the through hole 12a. A bearing portion (bearing) 16 including a roller 16a and a spherical sliding bearing 16b is accommodated.

  Returning to FIG.

  The front side of the swing arm 12 with the swing fulcrum B as the center of rotation is brought into contact with the measurement site D of the nozzle inner surface 5a by swinging in the direction of the arrow C, while the rear side of the swing arm 12 is the arrow. Swings in the E direction.

  The measurement site D is at a position of approximately 200 mm from the swing fulcrum B of the swing arm 12 toward the tip of the upper nozzle 5. The reason for specifying the measurement site D in this way is that the tip side of the upper nozzle 5 tends to be more eroded. When the tube hole of the upper nozzle 5 is cleaned with oxygen after the molten steel is discharged, the ladle is turned sideways. This is because slag is generated below the cylindrical hole of the upper nozzle 5 and the slag is removed, and as a result, it is confirmed that erosion occurs at a site of 100 mm in the front and rear with the measurement site D as the center. .

  A contact 13b at the tip of a spindle 13a of a dial gauge (vibration amount detecting means) 13 is brought into contact with the upper edge 12e of the rear arm 12d, and the vibration amount of the swing arm 12 is read by the dial gauge 13.

  As the dial gauge 13, a conventionally known one can be used, but a dial gauge having a measurement range of about 50 mm and capable of digitally displaying 0.01 mm as a minimum display amount is preferable.

  The dial gauge 13 is fixed to the disc portion 11b via a stand 17, and the position of the contact 13b can be adjusted by loosening the clamp tightening handle 17a and moving the dial gauge 13. ing.

  Further, when setting the dial gauge 13, the spindle 13a is slightly pushed up, and it is confirmed that the spindle 13a descends smoothly when the hand is released. If the spindle 13a does not descend smoothly, the tightening by the clamp tightening handle 17a is adjusted.

  Next, a measurement method using the thickness reduction measuring apparatus 10 having the above configuration will be described with reference to FIG. The remaining thickness of the nozzle is measured by the thickness reduction measuring device 10 at a frequency of once every 4 to 5 times in the number of times the steel is received by the ladle. In this case, it is necessary to replace the sliding nozzle bottom plate 6 and slide plate 8 (see FIG. 1) once every 4 to 5 times. Since the upper nozzle 5 is exposed during the replacement, measurement is performed in accordance with the timing. It depends.

  In addition, it is assumed that the ladle is lying down sideways and the molten steel is discharged.

  First, the measurer brings the lower arm 12c (see FIG. 5B) of the swing arm 12 into contact with the horizontal surface 11k formed in the slit 11h of the partition plate 11f, thereby making the swing arm 12 a measurement standard. Align with line M.

  Next, the dial gauge 13 is zero-set.

  Next, the measurer grips the handle 14 of the thickness reduction measuring device 10 and inserts the cylindrical portion 11 a into the cylindrical hole of the upper nozzle 5.

  When the cylindrical portion 11a is continuously inserted, the disc portion 11b comes into contact with the edge portion of the iron skin hole 2a. At this time, the step formed on the engaging portion 11d of the disc portion 11b engages with the peripheral portion thereof, so that the swing fulcrum B of the swing arm is the center of the iron hole 2a, that is, the measurement reference line. Positioned on M.

  Next, the rear arm 12 d of the swing arm 12 is gently pushed up in the direction of arrow E, and the protrusion 12 b on the tip end side of the swing arm 12 is brought into contact with the measurement site D.

  In this state, the display of the dial gauge 13 is read and recorded.

  When the distance from the swinging fulcrum B to the front protrusion 12b is S1, and the distance from the swinging fulcrum B to the contact position of the rear contact 13b is S2, the display part of the dial gauge 13 has S2 / S1. The swing amount of the swing arm 12 is displayed at the ratio.

  Therefore, the allowable maximum deflection amount of the swing arm 12 corresponding to the allowable remaining thickness of the upper nozzle 5 is determined in advance, and the value obtained by multiplying the allowable maximum deflection amount by the ratio of S2 / S1 is the value measured by the dial gauge 13. If the upper limit is set, it can be determined that the remaining thickness of the upper nozzle 5 has exceeded the control limit when the measured value exceeds the upper limit, and the replacement of the upper nozzle 5 can be determined.

  Note that the movement trajectory of the protrusion 12b in the swing arm 12 is arcuate, whereas the spindle 13a of the dial gauge 13 moves linearly, resulting in a measurement error in the direction in which the measured value decreases. However, this measurement error is minute and has no practical effect and can be regarded as an error range.

  After the measurement is completed, the swing arm 12 is separated from the measurement site D, and the cylindrical portion 11a is pulled out from the cylindrical hole of the upper nozzle 5.

  During this time, the time required for the measurement is about 5 seconds, and the measurement of the nozzle thickness can be completed in a short time. Therefore, it can be seen that it is practical even in a severe environment at high temperatures.

  In the measurement method shown in the above embodiment, the measurer directly reads the shake amount displayed on the dial gauge, but when using a dial gauge equipped with an output terminal for outputting a measurement result as a signal, For example, the measurement result can be transmitted wirelessly or wired to a computer in the management room and managed in the management room.

  In addition, although embodiment mentioned above demonstrated taking the ladle as an example, it is not restricted to this, It can apply also when measuring the remaining thickness of the nozzle-like refractory arrange | positioned at container bottom parts, such as a tundish. .

It is a longitudinal cross-sectional view which shows the nozzle structure of the ladle bottom part to which the thickness reduction measuring apparatus which concerns on this invention is applied. It is a side view which shows the structure of the thickness reduction amount measuring apparatus which concerns on this invention. FIG. 3 is a front view of FIG. 2. FIG. 3 is a bottom view of FIG. 2. FIG. 3 is an enlarged view of the swing arm mounting structure shown in FIG. 2, (a) is a front view, and (b) is a side view. It is sectional drawing which showed from a plane the structure of the bearing part provided in the rocking | fluctuation fulcrum of the rocking | fluctuation arm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support metal fitting 2 Iron skin 2a Iron skin hole 3 Lower receiving brick 4 Upper receiving brick 5 Upper nozzle 6 Bottom plate 7 Lower nozzle 8 Slide plate 9 Lower nozzle case 10 Thickening amount measuring device 11 Main body part 11a Tube part 11b Disk part 11c Through-hole 11d Engagement part 11e Tip edge 11f Partition plate 11h Slit 12 Swing arm 12b Projection part 13 Dial gauge 14 Handle 15 Pin 16 Bearing part D Measurement part M Measurement reference line

Claims (6)

A nozzle thickness reduction measuring device that measures the thickness reduction of a nozzle-like refractory attached to a steel receiving container such as a ladle or tundish,
A main body portion that has an engaging portion that can be engaged with a peripheral edge portion of the exterior hole formed in the steel receiving container;
A swing arm having a swing fulcrum in the main body, a front side of the swing fulcrum extending in the nozzle refractory and a rear side of the swing fulcrum extending outside the steel receiving container;
A contact portion provided at a tip of the swing arm and contacting an inner wall of the nozzle-like refractory;
A positioning unit for setting the swing arm to a measurement reference position;
A nozzle shape comprising: a swing amount detecting means for detecting the swing arm swing amount behind the swing support point when the contact portion abuts against the inner wall of the nozzle refractory. Refractory thickness reduction measuring device.   The nozzle-like refractory according to claim 1, further comprising: a cylindrical portion inserted into the exterior hole as the main body portion; and a disc portion fixed to the rear end in the insertion direction of the cylindrical portion and mounted on the exterior hole. Thinning amount measuring device.   The apparatus for measuring a reduction in thickness of a nozzle-like refractory according to claim 2, wherein an annular stepped portion that engages with the entire periphery of the peripheral edge of the exterior hole is formed in the disk portion as the engaging portion.   The nozzle-shaped refractory thickness reduction measuring device according to claim 2 or 3, wherein a viewing window for confirming a contact state between the contact portion and the nozzle-like refractory inner wall is formed on the disc portion.   The apparatus for measuring a reduction in thickness of a nozzle-like refractory according to any one of claims 1 to 4, wherein a swing fulcrum of the swing arm is pivotally supported by a bearing.   A dial gauge is provided as the shake amount detecting means, and the measuring element is configured to come into contact with the swing arm on the rear side of the swing support point in the swing direction. The nozzle thickness refractory thickness reduction measuring device according to any one of the preceding claims.

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