JPH09108802A - Detection of breakout and treatment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detecting method of breakout which can detect the breakout at high reliability in real time and can quickly treat thereafter, and a treating method thereof. SOLUTION: A sheath thermocouple 23 opened at the tip part or connected at the tip part is fitted to a block changing stand 16 containing a comb-tooth member 13 and a cooling grid 14 arranged just below a mold 12 in a continuous caster 10. The temp., at which the sheath thermocouple 23 is melted and connected with the heat of molten steel 19 leaked at the time of developing the breakout, is measured to detect the breakout.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breakout detection method and a processing method using the same, and more particularly, it is highly reliable and can detect a breakout in real time and can speed up subsequent processing. The present invention relates to a breakout detection method and a processing method using the same.

[0002]

2. Description of the Related Art Continuous casting of a slab by a continuous casting machine is performed by injecting molten steel from a tundish into a water-cooled mold, where the molten steel is primarily cooled to form a solidified shell,
For example, the inside of a batch exchange stand consisting of comb tooth members (comb, comb), cooling grid, support roll,
Cooling water is jetted while passing between the pinch rolls on the downstream side to completely solidify the slab. by the way,
The slab that is passing through the batch exchange stand directly below the mold is pulled out while gradually thickening the solidified shell.At that time, for example, in the gap between the comb tooth members or each cooling grid, the bulging is formed on the surface of the solidified shell. Large and small bulging parts occur. In such a bulged portion, the solidified shell becomes thin, so that the static pressure of the molten steel sometimes breaks the solidified shell, causing leakage of internal molten steel called breakout. Once the breakout occurs, the leaked molten steel is blown out of the batch exchange stand and is wound around the support roll while being solidified by the outside air, interrupting the continuous casting and lowering the productivity of the continuous casting machine.

Therefore, in order to solve this, for example, the "casting temperature measuring device" of JP-A-61-219456.
The breakout detection method described in the above specification is known. In this detection method, multiple thermocouples are thrust perpendicular to the plate in the mold plate of the mold, and based on the temperature information inside the mold obtained from the thermocouple, the breakout that occurs immediately below the mold is predicted. Is the way to do it. However, the breakout that can be predicted by this method is limited to the constrained breakout in which the solidified shell in the mold is peeled off and the hot molten steel contacts the mold plate directly, and it is possible to predict all types of breakout. There wasn't. Further, of course, it was relatively poor in reliability because it was a prediction based on the mold side. Moreover, as another problem, by pushing a large number of thermocouples against the mold plate, various constraints such as strength are disturbed and the design of the mold plate becomes more complicated, and the thermocouples in the control unit are different. There is also a drawback that a detection circuit is required for each and the circuit becomes complicated and the cost increases. As a result, in actual operation, without relying on such prediction, the worker on the casting floor can visually recognize the flame rising from the bottom of the floor at the time of breakout and hear the explosion sound at that time, and the breakout Was commonly detected.

[0004]

However, in the detection method of the prior art which relies on the sight and hearing of the worker described above,
Workers do not actually look at the breakout site in front of them, but they usually indirectly detect it as flames or roars on the casting floor several meters or more away, which takes time to confirm. However, the measures such as stopping the molten steel supply from the tundish to the mold will be delayed. As a result, the batch exchange stand is contaminated with a large amount of molten steel, and it is necessary to replace the batch exchange stand, it takes time to repair the dirty batch exchange stand after replacement, and in the worst case, the mold There was a risk that molten steel would boil at the top. Therefore, in order to solve these problems, it is conceivable to dispose a surveillance camera, for example, in the vicinity of just under the mold. However, immediately below the mold, cooling water was sprayed on the hot slab to generate a large amount of water vapor, which impairs the view of the surveillance camera and is predicted to reduce the reliability of breakout detection. It The present invention has been made in view of the above circumstances, and is highly reliable, can detect breakouts in real time, is easy to design, can be deployed at a relatively low cost, and can quickly perform post-breakout processing. An object is to provide an out detection method and a processing method using the same.

[0005]

According to the present invention, there is provided a semiconductor device comprising:
The breakout detection method described is to attach a sheath thermocouple with an open front end or a connected front end to a batch exchange stand that includes a comb tooth member and a cooling grid that is placed immediately below the mold of a continuous casting machine, and leaks when a breakout occurs. With the heat of the molten steel, the temperature at which the sheath thermocouple is melt-bonded is measured to detect breakout. A breakout detecting method according to a second aspect of the present invention is the breakout detecting method according to the first aspect, wherein the sheath thermocouple is routed around the entire circumference of the collective exchange stand collectively or in a divided manner. The breakout detection method according to claim 3 is the breakout detection method according to claim 1 or 2, wherein the sheath thermocouple has a through hole formed in the comb tooth member and a through hole formed in the cooling grid. It was attached to the batch exchange stand in a state where it was loosely inserted.

In the breakout detecting method according to a fourth aspect of the present invention, the backward Raman scattered light is detected by injecting pulsed light into a collective exchange stand including a comb tooth member and a cooling grid, which is arranged immediately below the mold of a continuous casting machine. , The intensity ratio of the Stokes light and the half-Stokes light and its return time, the optical fiber of the optical fiber thermometer that can measure the position where the backward Raman light is generated and its temperature is attached, and the leakage of molten steel at the time of breakout and its It detects the position and. The breakout detection method according to claim 5 is the breakout detection method according to claim 4,
The optical fibers are routed around the entire circumference of the collective exchange stand collectively or in a divided manner. The breakout detection method according to claim 6 is the breakout detection method according to claim 4 or 5, wherein the optical fiber is inserted into a through hole formed in the comb tooth member and a through hole formed in the cooling grid. It was made to be attached to the batch exchange stand in the inserted state.
The breakout detection method according to claim 7, wherein a sheath thermocouple with a front end open or a front end connection is attached to a batch exchange stand that is arranged immediately below the mold of a continuous casting machine and includes small diameter rolls arranged in a staggered manner. The breakout is detected by measuring the temperature at which the sheath thermocouple is melt-bonded by the heat of the molten steel leaked when the out occurs. The breakout detection method according to claim 8, wherein pulsed light is incident on a collective exchange stand that is arranged immediately below the mold of a continuous casting machine and includes small-diameter rolls arranged in a staggered manner, and the backward Raman scattered light is detected. From the intensity ratio of the Stokes light and the half-Stokes light and its return time, the optical fiber of the optical fiber thermometer that can measure the position where the backward Raman light is generated and its temperature is attached, and the leakage of molten steel at the time of breakout and its position Is detected.

In the breakout treatment method according to the ninth aspect, a sheath thermocouple with a front end open or a front end connection is attached to a collective exchange stand including a comb tooth member and a cooling grid arranged directly below the mold of a continuous casting machine. After detecting the breakout by measuring the temperature at which the sheath thermocouple is melt-bonded by the heat of the molten steel leaked when the breakout occurs, the sliding nozzle or stopper is closed and injected from the tundish into the mold. While stopping the supply of the molten steel to stop the casting, after the leakage, so that the molten steel that has begun to solidify does not wind around the support roll etc.
It was designed to be automatically pulled out at 6.0 m / min. Here, the withdrawal speed of the slab immediately after the breakout was 0.
If it is less than 7 m / min, adhesion or wrapping of molten steel occurs on the support roll, which causes inconvenience such that the slab cannot be pulled out, and if it exceeds 6.0 m / min, the splattering range of molten steel that falls on the slab to be drawn, That is, the damage range of the slab is increased, and thus the damage range of the support rolls arranged in the cooling zone is expanded. The same applies to the following claims 10 to 12. The withdrawal speed of the cast immediately after the breakout is preferably set so that the molten steel is scattered within the range of the batch exchange stand (usually within 3 m from the lower end of the mold).

According to a tenth aspect of the breakout treatment method of the present invention, pulsed light is incident on a collective exchange stand including a comb tooth member and a cooling grid disposed immediately below the mold of a continuous casting machine to detect backward Raman scattered light. , The intensity ratio of the Stokes light and the half-Stokes light and its return time, the optical fiber of the optical fiber thermometer that can measure the position where the backward Raman light is generated and its temperature is attached, and the leakage of molten steel at the time of breakout and its After detecting the position, the sliding nozzle or the stopper is operated to close, and the casting is stopped by stopping the supply of the molten steel injected from the tundish into the mold, and after leakage,
In order to prevent the molten steel which has begun to solidify from winding around the support roll or the like, the slab immediately after the breakout is 0.7 to 6.
It was designed to be automatically pulled out at 0 m / min. Claim 1
In the breakout treatment method described in 1, a breakout occurs by attaching a sheath thermocouple with a front end open or a front end connection to a batch exchange stand that is arranged immediately below the mold of a continuous casting machine and includes staggered small diameter rolls. When the breakthrough is detected by measuring the temperature at which the sheath thermocouple is melt-bonded by the heat of the molten steel that leaks at some time, the sliding nozzle or the stopper is closed and the molten steel injected from the tundish into the mold is detected. The supply is stopped to stop casting, and the molten steel that has begun to solidify after leaking is automatically drawn out at 0.7 to 6.0 m / min immediately after breakout so that the molten steel does not wind around the support roll. I decided to do it. The breakout processing method according to claim 12, wherein pulsed light is incident on a batch exchange stand that is arranged immediately below the mold of a continuous casting machine and includes small-diameter rolls arranged in a zigzag pattern, and the backward Raman scattered light is detected. From the intensity ratio of the Stokes light and the half-Stokes light and its return time, the optical fiber of the optical fiber thermometer that can measure the position where the backward Raman light is generated and its temperature is attached, and the leakage of molten steel at the time of breakout and its position After detecting, the sliding nozzle or stopper is operated to close, and the casting is stopped by stopping the supply of molten steel injected from the tundish into the mold, and after leakage,
In order to prevent the molten steel which has begun to solidify from winding around the support roll or the like, the slab immediately after the breakout is 0.7 to 6.
It was designed to be automatically pulled out at 0 m / min.

[0009]

In the breakout detection method and the treatment method using the breakout detection method according to claims 1 to 12, when a breakout occurs in which molten steel breaks the solidified shell and leaks to the outside immediately below the mold of the continuous casting machine, Molten steel falls on the fiber optics of a sheath thermocouple or fiber optic thermometer attached to a batch exchange stand. As a result, in the case of a sheath thermocouple, the protective tube and the thermocouple wires made of a pair of different materials that are housed inside and protected by the temperature are melted, and the thermoelectric effect (Seebeck effect) causes the thermoelectric effect. An electromotive force is generated at the junction between the pair of wires, and the breakout is detected by detecting it. In the case of the sheath thermocouple connected to the front portion, the disconnection of the sheath thermocouple can be inspected by checking the energization state between the thermocouple wires at appropriate times. In the case of an optical fiber thermometer, the backward Raman scattered light is detected by injecting pulsed light, and the position of the backward Raman light and its temperature are determined from the intensity ratio of the Stokes light and the half-Stokes light and the return time. And measure. In particular, in the breakout detection method according to claims 2 and 5, the optical fiber of the sheath thermocouple or the optical fiber thermometer is provided around substantially the entire circumference of the collective exchange stand instead of being spotted around the collective exchange stand. Since the molten steel is laid around, when a breakout occurs just below the mold of the continuous casting machine, the molten steel almost certainly falls on a part of the sheath thermocouple or the optical fiber thermometer to detect the occurrence of the breakout.

In the breakout detection method according to claims 3 and 6, the sheath thermocouple or the optical fiber of the optical fiber thermometer has a through hole formed in the comb tooth member of the collective exchange stand and a through hole formed in the cooling grid. The molten steel, which is attached while being loosely inserted in the routing route that is easy to work, and which leaks at the time of breakout falls only on the portion of the sheath thermocouple or the optical fiber exposed between the comb tooth member and the cooling grid. The other portions are hidden by being inserted into the through holes of the comb-teeth member or the cooling grid and hidden, so that the exposed portion of the sheath thermocouple or the optical fiber, which is easily damaged for some reason, can be reduced. Further, in the breakout treatment method according to any one of claims 9 to 12, after detecting the occurrence of breakout, the sliding nozzle or the stopper of the tundish is operated to close, whereby the injection of the molten steel into the mold is stopped and the casting is performed. Is stopped, and the slab in the batch exchange stand is automatically drawn out at a high speed with it, so the amount of molten steel leaked by the breakout can be reduced as much as possible, which reduces the contamination degree of the batch exchange stand.
If a breakout occurs, it is possible to cancel the replacement of the batch exchange stand that has been performed in most cases, or even if that exchange is performed, the amount of metal that wraps around the support roll, etc. will decrease and repair The labor and time can be reduced.

[0011]

In the breakout detection method and the treatment method using the same according to the present invention, the breakout is detected by the sheath thermocouple or the optical fiber thermometer attached to the batch exchange stand just below the mold. As a result, breakout detection is highly reliable, real-time detection is possible, and subsequent processing can be performed quickly. Further, in the breakout detection method according to claims 2 and 5, the sheath thermocouple or the optical fiber of the optical fiber thermometer is provided around substantially the entire circumference of the collective exchange stand instead of being spotted around the collective exchange stand. Since it is laid around, the occurrence of breakout can be detected almost certainly.

In the breakout detection method according to the third and sixth aspects, the sheath thermocouple or the optical fiber is loosely inserted into the through hole formed in the comb tooth member and the through hole formed in the cooling grid of the batch exchange stand. Since it is installed in the state, a convenient routing path for the sheath thermocouple or the optical fiber is secured, and the exposed portion of the sheath thermocouple or the optical fiber, which is not so related to the detection of the breakout, can be made as small as possible, and the breakout occurs. Prevents damage to the sheath thermocouple or optical fiber when not in use. Further, in the breakout treatment method according to any one of claims 9 to 12, after the breakout is detected, for example, a stopper provided on the tundish is lowered to close the nozzle, and injection of molten steel into the mold is stopped to perform casting. While stopping, the slabs in the batch exchange stand are automatically withdrawn at high speed, so the amount of molten steel leaked by the breakout can be suppressed as much as possible, which reduces the contamination level of the batch exchange stand and reduces While it is not necessary to replace the replacement stand, the productivity of continuous casting can be improved, and even when the replacement is performed, the labor and time for restoration can be shortened.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is a vertical cross-sectional view of a schematic configuration of a continuous casting machine to which a breakout detection method according to a first embodiment of the present invention and a processing method using the same are applied.
2 is an enlarged vertical cross-sectional view of the main part of the continuous casting machine immediately below the mold, FIG. 3 is an enlarged front view of the immediate vicinity of the mold, FIG. 4 is an explanatory view of a control unit of the breakout detection processing device, and FIG. FIG. 6 is an enlarged front view of the vicinity of a portion directly below a mold of a continuous casting machine to which a breakout detection method according to a second embodiment of the present invention and a processing method using the same are applied.

As shown in FIGS. 1 to 3, the continuous casting machine 10 to which the breakout detecting method according to the first embodiment of the present invention and the processing method using the same are applied, is directed from upstream to downstream. The mold 12 placed under the immersion nozzle 11a of the tundish 11 on the casting floor, a large number of comb-tooth members 13 and the comb-tooth members 13 vertically hung on the lower end surface of the mold 12 at a predetermined interval. A batch exchange stand 16 having a cooling grid 14 arranged in a comb-tooth shape and a support roll 15 arranged below the cooling grid 14 and a large number of pinch rolls 17 arranged in an arc shape in a side view are provided. I have it. When the stopper 18 is pulled up, the immersion nozzle 11a of the tundish 11 is opened and the molten steel 19 is supplied into the mold 12. Molten steel 1
9 is a water-cooled primary cooling device 20 equipped in the mold 12.
Thereby, the primary cooling is gradually performed from the portion in contact with the inner surface of the mold 12. As a result, the solidified shell 19a is formed. Then, the solidified shell 19a is gradually thickened by the cooling water for secondary cooling being jetted from the secondary cooling water nozzle 34 while passing between the comb tooth member 13, the cooling grid 14, and the support roll 15. Then, at least while passing through the pinch roll 17, the slab is solidified to the center. Reference numeral 21 is a water-cooled secondary cooling device, reference numeral 34 is a secondary cooling water nozzle, reference numeral 35 is a splash prevention plate, reference numeral 3
Reference numeral 6 is a support base, and instead of the immersion nozzle 11a of the tundish 11, an immersion nozzle equipped with a sliding nozzle may be adopted.

As shown in FIG. 1, the continuous casting machine 10 is provided with a breakout processing device 22 having a breakout detection function. The breakout processing device 22 includes a sheath thermocouple 23, which is an example of a breakout detection device that is routed in four divisions for each side, and a control unit 24 on the entire circumference immediately below the mold 12 of the continuous casting machine 10. doing. As shown in FIG. 4, the sheath thermocouple 23 has a diameter of 1 to
A 5 mm, preferably 1 to 3 mm, stainless steel protective tube 23a is filled with a powdered inorganic insulator such as magnesium oxide and sealed, and for example, a pair of thermocouple wires made of different materials such as platinum and platinum rhodium. It is a long temperature sensor in which 23b and 23c are accommodated in a parallel state, and the tips are connected. Since the tip portions of the thermocouple wires 23b and 23c are connected, it is possible to check the energization state between the thermocouple wires 23b and 23c in a timely manner and inspect the sheath thermocouple 23 for breaks. If the diameter of the protective tube 23a is less than 1 mm, the manufacturing cost of the thermocouple becomes high, and the chipping or holding strength is insufficient during the installation work. If it exceeds 5 mm, the molten steel at the breakout may not be melted. There is

As shown in the partially enlarged view of FIG.
Inside the comb-tooth members 13 arranged at regular intervals on the lower surface of the top and the comb-tooth portions 14a arranged at regular intervals above the cooling grid 14 on the uppermost stage, penetrating through both side surfaces. Holes 13a and 14b are formed, and the sheath thermocouple 23 is drawn around these through holes 13a and 14b arranged on each side of the batch exchange stand 16 in a state of being loosely inserted in series. As a result, a route for easy operation of the sheath thermocouple 23 is secured, the exposed portion of the sheath thermocouple 23, which is not so related to the detection of the breakout, can be made as small as possible, and the sheath thermocouple when the breakout does not occur. 23 can be prevented from being damaged. Instead of the sheath thermocouple 23, pulsed light is incident to detect backward Raman scattered light, and from the intensity ratio of the Stokes light to the half Stokes light and its return time, the position where the backward Raman light is generated and its temperature are detected. Alternatively, the optical fiber of the optical fiber thermometer capable of measuring and may be drawn in series to the through hole 13a of the comb tooth member 13 and the through hole 14b of the comb tooth portion 14a of the cooling grid 14. Next, the control unit 24 will be described in detail with reference to FIG.

As shown in FIG. 4, each thermocouple wire 23b,
A converter 25 and a thermometer 26 are sequentially connected to one end of 23c, and the thermometer 26 is connected to the controller 24. The control section 24 has a breakout determination means 27 connected to a thermometer 26, an operation process circuit 28, and a breakout issuing means 29. The operation process circuit 28 receives the signal of the breakout determination,
Re-judgment is performed based on fluctuations in the molten metal level, pouring amount, and casting speed, and a sliding nozzle or stopper closing command is issued. Further, as shown in FIG. 1, the breakout one-shot means 29 closes the immersion nozzle 11a of the tundish 11 with a stopper 18 to stop the injection of the molten steel 19 into the mold 12, and at the same time, sequentially, I zone, II In the zone, the injection of the cooling water from the secondary cooling device 21 to the surface of the solidified shell 19a is stopped, the injection of the cooling water from between the pinch rolls 17 in the III zone, the IV zone, ... Is stopped, and then 0.7-6.0 from the continuous casting machine 10 slab
It is a control means for quickly drawing out at a high speed of m / min to prevent the molten steel 19 that has begun to solidify after leakage from winding around the support roll 15 or the like.

When the drawing speed of the slab is less than 0.7 m / min, it is difficult to draw before the molten steel 19 applied to the support roll 15 or the like is solidified due to breakout, and when it exceeds 6.0 m / min, The pulling out may be too fast, and the support roll 15 or the like may be damaged. When the molten steel 19 of about 1400 to 1500 ° C leaked by the breakout falls on the sheath thermocouple 23, the stainless steel protection tube 23a having a melting temperature of about 1200 ° C is melted and the thermocouple wires 23b and 23c arranged in parallel. Is heat-sealed, and an electromotive force is generated at the joint between the thermocouple wires 23b and 23c due to the thermoelectric effect, whereby the temperature is measured and the result is sent to the control unit 24. In the controller 24, the breakout determination means 27 determines whether or not there is a breakout based on the measured temperature. The breakout detection threshold can be arbitrarily adjusted by changing the material and the thickness of the protective tube 23a. However, since the temperature of the molten steel 19 is usually 1400 to 1500 ° C. as described above,
The detection threshold is not melted by the heat transmitted from the solidification shell 19a side to the batch exchange stand 16 during operation, 30
The temperature is preferably 0 to 1400 ° C. Regarding the position where the thermocouple wires 23b and 23c of the sheath thermocouple 23 are short-circuited, a pulse wave is applied from the terminals of the thermocouple wires 23b and 23c and the reflection time is measured to measure the position. By measuring the inductance of the thermocouple 23, its position can be estimated. When a breakout is detected, the detection signal is sent to the operation process circuit 28,
The breakout one-shot means 29 described above is activated.

Next, a breakout detecting method according to the first embodiment of the present invention using the continuous casting machine 10 and a processing method using the breakout detecting method will be described. As shown in FIG. 1, when the stopper 18 is pulled up, the molten steel 19 in the tundish 11 is poured into the mold 12. Mold 1
The bottom of 2 is closed by the tip surface of the dummy bar 30, and after the solidified shell 19a having a predetermined thickness is formed, the dummy bar 30 is gradually pulled out downward and continuous casting is started. The cast slabs sequentially pass between the comb tooth member 13, the cooling grid 14 and the support roll 15 of the batch exchange stand 16, and are pulled out to the pinch roll 17. During that time, the primary cooling device 20 and the support rolls 15 and the pinch rolls 17 arranged between the two
Cooling water is jetted from the next cooling water nozzle 34 to the surface of the slab to completely solidify the slab to the center. During this continuous casting, for example, as shown in FIG. 3, the mold 12 and the comb tooth member 1
If a breakout occurs in the gap between the molten steel 19 and the cord 3, the cord-shaped sheath thermocouple 23 is drawn around the entire circumference between the comb tooth member 13 and the uppermost cooling grid 14, so that the molten steel 19 Always falls on a part of the sheath thermocouple 23.

As a result, the protective tube 23a and the thermocouple wire 2 are
3b and 23c are melted, and the thermocouple wire 2 is generated by the thermoelectric effect.
3b and 23c are short-circuited, an electromotive force is generated at the melted joint portion, and the breakout is detected by detecting the electromotive force. After detecting the breakout, the control unit 2
The breakout one-shot means 29 of 4 operates to close the stopper 18 of the immersion nozzle 11a of the tundish 11, whereby the injection of the molten steel 19 into the mold 12 is stopped and the casting is stopped. After that, batch exchange stand 16
The ingot has a low speed of, for example, 0.5 m / min, but is automatically drawn at a high speed of 1.0 m / min, so the amount of molten steel leaked by the breakout is reduced as much as possible. The degree of contamination of the exchange stand 16 can be reduced. Therefore, if a breakout occurs in the past, it is possible to omit the replacement of the batch exchange stand 16 that is almost always performed, or even when the replacement is performed, the amount of the bare metal wound around the support roll 15 is reduced, The trouble and time for repair can be shortened. By the way, when the sheath thermocouple 23 with a diameter of 2.6 mm was used and the time until the series of breakout countermeasures called "breakout one shot" described above was finally measured, It took 15 to 30 seconds for a worker to judge a breakout, while this means 2
I was able to deal with it in about 3 seconds.

As described above, since the breakout is detected by the sheath thermocouple 23 that is routed around the entire circumference of the batch exchange stand 16, the breakout can be detected with high reliability and in real time. Further, the subsequent processing can be performed quickly. If, for example, ordinary thermocouples that measure the temperature like a spot are continuously arranged on the entire circumference of the batch exchange stand 16, the same use as the sheath thermocouple 23 can be performed. On the other hand, in the first embodiment, the number of thermocouples used is small, the electric circuit meter is also simple, and the design and manufacturing are simple and the cost is low.

Next, a breakout detecting method according to the second embodiment of the present invention and a processing method using the same will be described with reference to FIG. In the second embodiment, as the collective exchange stand 31, instead of the comb tooth member 13 and the cooling grid 14 used in the first embodiment,
A small-diameter roll 32 arranged in a staggered manner is adopted, and an optical fiber thermometer 33 which replaces the sheath thermocouple 23 is adopted.
As shown by the solid line in FIG. 5 along the wavy side of the small-diameter roll 32 in the second step from the top, or as shown by the chain double-dashed line in FIG. Rotating shaft 32a
While being inserted like a bead into the shaft center hole, the batch exchange stand 31 is laid all around. Instead of the optical fiber thermometer 33, the sheath thermocouple 23 may be used as in the first embodiment. When the breakout is detected by the optical fiber thermometer 33, the pulsed light is incident on the optical fiber to detect the backward Raman scattered light, and the backward Raman light is detected from the intensity ratio of the Stokes light and the half-Stokes light and the return time thereof. By measuring the position of occurrence of the and the temperature thereof, not only the occurrence of the breakout but also the position of the occurrence thereof can be detected. This makes it possible to deal with the subsequent breakout more quickly and satisfactorily.

The embodiment of the present invention has been described above.
The present invention is not limited to these, and even if the design is changed without departing from the scope of the invention, the present invention is included. For example, the location where the sheath thermocouple or the optical fiber of the optical fiber thermometer is attached to the collective exchange stand may be not only the upper end portion of the collective exchange stand as in the embodiment but also the central portion or the lower portion. May be attached. Further, the mounting method may be winding, for example, in a zigzag or corrugated manner, and the sheath thermocouple or the optical fiber may be provided on at least one surface of the collective exchange stand, not on the entire circumference of the collective exchange stand. Further, in the first embodiment, the sheath thermocouple with the front portion connected is attached, but the sheath thermocouple with the front portion open may be adopted without being limited to this.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal cross-sectional view of a continuous casting machine to which a breakout detection method and a processing method using the same according to a first embodiment of the present invention are applied.

FIG. 2 is an enlarged vertical cross-sectional view of a main part of the continuous casting machine, which is located immediately below a mold.

FIG. 3 is an enlarged front view of a portion right below the mold.

FIG. 4 is an explanatory diagram of a control unit of the breakout detection processing device.

FIG. 5 is an enlarged front view of the vicinity of directly below a mold of a continuous casting machine to which the breakout detection method according to the second embodiment of the present invention and a processing method using the same are applied.

[Explanation of symbols]

10 Continuous Casting Machine 11 Tundish 11a Immersion Nozzle 12 Mold 13 Comb Tooth Member 13a Through Hole 14 Cooling Grid 14a Comb Tooth 14b Through Hole 15 Support Roll 16 Batch Exchange Stand 17 Pinch Roll 18 Stopper 19 Molten Steel 19a Solidification Shell 20 Primary Cooling Device 21 Secondary cooling device 22 Breakout treatment device 23 Sheath thermocouple 23a Protective tube 23b Thermocouple wire 23c Thermocouple wire 24 Controller 25 Converter 26 Thermometer 27 Breakout determination means 28 Operation process circuit 29 Breakout one Generating means 30 Dummy bar 31 Batch exchange stand 32 Small-diameter roll 32a Rotating shaft 33 Optical fiber thermometer 34 Secondary cooling water nozzle 35 Splash prevention plate 36 Support stand

Claims (12)

[Claims] 1. A sheath thermocouple having an open front end or a front end connected to a batch exchange stand including a comb tooth member and a cooling grid, which is arranged immediately below a mold of a continuous casting machine, to remove molten steel leaked when a breakout occurs. A breakout detecting method, characterized in that the temperature at which the sheath thermocouple is melt-bonded is measured by heat to detect the breakout. 2. The breakout detection method according to claim 1, wherein the sheath thermocouple is laid all together or divided around substantially the entire circumference of the batch exchange stand. 3. The sheath thermocouple is attached to the collective exchange stand in a state of being loosely inserted into a through hole formed in the comb tooth member and a through hole formed in the cooling grid. Claim 1 or 2
Breakout detection method described. 4. A backward exchange Raman scattered light is detected by injecting pulsed light into a collective exchange stand including a comb tooth member and a cooling grid arranged immediately below the mold of a continuous casting machine, and the Stokes light and the half-Stokes light are detected. From the intensity ratio and its return time, the optical fiber of the optical fiber thermometer that can measure the position where the backward Raman light is generated and its temperature is attached, and the leakage of molten steel at the time of breakout and its position are detected. Breakout detection method. 5. The breakout detection method according to claim 4, wherein the optical fibers are routed collectively or divided around substantially the entire circumference of the collective exchange stand. 6. The optical fiber is attached to the collective exchange stand in a state of being loosely inserted into a through hole formed in the comb tooth member and a through hole formed in the cooling grid. Claim 4 or 5
Breakout detection method described. 7. A molten steel leaked when a breakout occurs when a sheath thermocouple with an open front end or a front end is attached to a batch exchange stand that is arranged immediately below the mold of a continuous casting machine and includes small diameter rolls in a staggered arrangement. A breakout detection method, characterized in that the breakout is detected by measuring the temperature at which the sheath thermocouple is melt-bonded with the heat of. 8. The Stokes light and the half-Stokes light are detected by injecting pulsed light into a collective exchange stand, which is arranged immediately below the mold of a continuous casting machine and includes small rolls in a staggered arrangement, to detect backward Raman scattered light. The optical fiber of the optical fiber thermometer that can measure the position where the backward Raman light is generated and its temperature from the intensity ratio of
A breakout detection method, which comprises detecting leakage of molten steel and its position when a breakout occurs. 9. A sheath thermocouple with an open front end or a front end is attached to a batch exchange stand including a comb-tooth member and a cooling grid arranged immediately below the mold of a continuous casting machine, and the molten steel leaked at the time of breakout occurs. After detecting the breakout by measuring the temperature at which the sheath thermocouple is melt-bonded by heat, the sliding nozzle or the stopper is closed to stop the supply of molten steel injected from the tundish into the mold. While stopping casting, the molten steel which has begun to solidify after leakage is automatically drawn out at 0.7 to 6.0 m / min immediately after breakout so that the molten steel does not wind around the support roll or the like. Breakout processing method. 10. A backward exchange Raman scattered light is detected by injecting pulsed light into a collective exchange stand including a comb tooth member and a cooling grid arranged immediately below the mold of a continuous casting machine,
From the intensity ratio of the Stokes light to the half-Stokes light and its return time, an optical fiber thermometer that can measure the position where the backward Raman light was generated and its temperature was attached, and the leakage of molten steel at the time of breakout and its position After detecting that, the sliding nozzle or stopper is closed to stop the supply of molten steel injected from the tundish into the mold to stop casting, and after leakage, the molten steel that has begun to solidify is the support roll. A breakout treatment method, characterized in that the slab immediately after breakout is automatically drawn out at 0.7 to 6.0 m / min so as not to wind around. 11. Arranged directly under the mold of a continuous casting machine,
In a batch exchange stand including small diameter rolls arranged in a staggered manner,
Attach a sheath thermocouple with an open front end or a connected front end, measure the temperature at which the sheath thermocouple is melt-bonded by the heat of molten steel that leaks when a breakout occurs, and detect the breakout, then slide nozzle or stopper By closing, stopping the supply of molten steel injected into the mold from the tundish and stopping casting,
After the leakage, the molten steel that began to solidify was prevented from winding around the support roll and the like, and the slab immediately after the breakout was treated with 0.
A breakout processing method, characterized in that automatic withdrawal is performed at 7 to 6.0 m / min. 12. The continuous casting machine is arranged immediately below the mold,
In a batch exchange stand including small diameter rolls arranged in a staggered manner,
Optical fiber of an optical fiber thermometer capable of detecting the backward Raman scattered light by injecting pulsed light and measuring the position where the backward Raman light is generated and its temperature from the intensity ratio of the Stokes light and the half-Stokes light and its return time. After detecting the leakage of molten steel and its position when a breakout occurs, close the sliding nozzle or stopper to stop the supply of molten steel injected into the mold from the tundish and stop casting. At the same time, to prevent the molten steel that began to solidify after leakage from wrapping around the support rolls, etc.
A breakout processing method, which is characterized in that automatic drawing is performed at a rate of up to 6.0 m / min.