KR101109450B1 - Method for estimating clogging degree of submerged entry nozzle and method for estimating time of changing submerged entry nozzle - Google Patents

Method for estimating clogging degree of submerged entry nozzle and method for estimating time of changing submerged entry nozzle Download PDF

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KR101109450B1
KR101109450B1 KR1020100040447A KR20100040447A KR101109450B1 KR 101109450 B1 KR101109450 B1 KR 101109450B1 KR 1020100040447 A KR1020100040447 A KR 1020100040447A KR 20100040447 A KR20100040447 A KR 20100040447A KR 101109450 B1 KR101109450 B1 KR 101109450B1
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South Korea
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height
immersion nozzle
molten steel
estimating
nozzle
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KR1020100040447A
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Korean (ko)
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KR20110121041A (en
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권효중
문홍길
장진수
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현대제철 주식회사
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Abstract

The present invention includes the steps of obtaining a first height of the stopper for the amount of molten steel discharged through the immersion nozzle in the steady state in the tundish; Acquiring a second height which is a height of a stopper for discharging the molten steel in the state in which the immersion nozzle is blocked; Obtaining a blockage index of the immersion nozzle using the first height and the second height; And estimating a degree of clogging of the immersion nozzle based on the blockage index, and a method of estimating a degree of immersion nozzle clogging and a method of estimating immersion nozzle replacement time.

Description

METHODS FOR ESTIMATING CLOGGING DEGREE OF SUBMERGED ENTRY NOZZLE AND METHOD FOR ESTIMATING TIME OF CHANGING SUBMERGED ENTRY NOZZLE}

The present invention relates to a method for estimating the degree of clogging of an immersion nozzle and a method for estimating an immersion nozzle replacement time in continuous casting.

In general, a continuous casting machine is a facility for producing slabs of a constant size by receiving a molten steel produced in a steelmaking furnace and transferred to a ladle in a tundish and then supplying it as a mold for a continuous casting machine.

The continuous casting machine includes a ladle for storing molten steel, a continuous casting machine mold for cooling the tundish and the molten steel discharged from the tundish to form a casting having a predetermined shape, and a casting formed in the mold connected to the mold. It includes a plurality of pinch roller to move.

In other words, the molten steel tapping out of the ladle and tundish is formed of a slab (Slab) or bloom (Bloom), billet (Billet) having a predetermined width and thickness in the mold and is transferred through the pinch roller.

The present invention is to provide a method for estimating the degree of clogging of an immersion nozzle and a method for estimating the immersion nozzle replacement time in continuous casting.

In order to solve the above problems, an immersion nozzle clogging estimation method according to an embodiment of the present invention includes: obtaining a first height of a stopper for the amount of molten steel discharged through a immersion nozzle in a steady state in a tundish; Acquiring a second height which is a height of a stopper for discharging the molten steel in the state in which the immersion nozzle is blocked; Obtaining a blockage index of the immersion nozzle using the first height and the second height; And estimating the degree of blockage of the immersion nozzle based on the blockage index.

According to an aspect of an embodiment of the present invention, the first height may be obtained by Equation 1 below.

[Equation 1]

H 0 [mm] = discharge rate [ton / min] × 7.01 + 3.74

H 0 is the first height.

According to one embodiment of the present invention, the blockage index can be obtained by the following equation (2).

[Formula 2]

Blockage Index = 1-H 0 / H

H 0 First height (mm)

H: 2nd height (mm)

Another embodiment of the present invention, the immersion nozzle replacement timing estimation method, comprising: obtaining a first height of the stopper for the amount of molten steel discharged through the immersion nozzle in the steady state in the tundish; Acquiring a plurality of second heights, which are the heights of the stoppers for discharging the molten steel in a state where the immersion nozzles are blocked, over time; Acquiring a plurality of clogging indexes of the immersion nozzle using the first height and the second height; Measuring a nozzle clogging speed by using a change amount of the plurality of clogging indexes; And predicting the blockage index according to the nozzle clogging speed, and estimating the immersion nozzle replacement time based on the predicted blockage index.

Here, the first height may be obtained by Equation 1 above.

The blockage index may be obtained by Equation 2 above.

Here, according to the nozzle clogging speed, the step of estimating the plugging index, and estimating the replacement nozzle replacement time based on the predicted plugging index, the timing of the plugging index is 0.70 estimated as the replacement timing of the dipping nozzle It may include the step.

According to one embodiment of the present invention, in the continuous casting, when the molten steel is discharged into the mold by the stopper method, the degree of clogging of the immersion nozzle can be estimated, and productivity can be expected to be improved. In addition, the nozzle clogging time can be predicted to determine whether the next ladle is taken to prevent the casting interruption due to the nozzle clogging in advance.

1 is a side view showing a continuous casting machine according to an embodiment of the present invention.
Figure 2 is a conceptual diagram for explaining the continuous caster of Figure 1 centered on the flow of molten steel (M).
Figure 3 is a graph showing the relationship between the height of the stopper and the discharge amount of the molten steel in the steady state associated with one embodiment of the present invention.
Figure 4 is a graph showing the weight of the ladle, the weight of the tundish, the casting speed and the blockage index in the first example of the actual state associated with an embodiment of the present invention.
FIG. 5 is a graph showing the weight of a ladle, the weight of a tundish, the casting speed and the blockage index in a second example of a real state related to an embodiment of the present invention. FIG.
6 is a flowchart illustrating a method of estimating a degree of clogging of an immersion nozzle and a method of estimating immersion nozzle replacement time, which is an embodiment of the present invention;

Hereinafter, a method of estimating the degree of clogging of an immersion nozzle and a method of estimating immersion nozzle replacement time according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the present specification, different embodiments are given the same or similar reference numerals for the same or similar configurations, and the description is replaced with the first description.

Continuous casting is a casting method in which a casting or steel ingot is continuously extracted while solidifying molten metal in a mold without a bottom. Continuous casting is used to manufacture simple products such as squares, rectangles, circles, and other simple cross-sections, and slab, bloom and billets, which are mainly for rolling.

The type of continuous casting machine is classified into vertical type, vertical bending type, vertical axis difference bending type, curved type and horizontal type. 1 and 2 illustrate a curved shape.

1 is a side view showing a continuous casting machine related to an embodiment of the present invention.

Referring to this drawing, the continuous casting machine may include a tundish 20, a mold 30, secondary cooling tables 60 and 65, a pinch roll 70, and a cutter 90.

The tundish 20 is a container that receives molten metal from the ladle 10 and supplies molten metal to the mold 30. Ladle 10 is provided in a pair, alternately receives molten steel to supply to the tundish 20. In the tundish 20, the molten metal supply rate is adjusted to the mold 30, the molten metal is distributed to each mold 30, the molten metal is stored, and the slag and the non-metallic inclusions are separated.

The mold 30 is typically made of water-cooled copper and allows the molten steel to be primary cooled. The mold 30 forms a hollow portion in which molten steel is accommodated as a pair of structurally facing faces are opened. In manufacturing the slab, the mold 30 comprises a pair of barriers and a pair of end walls connecting the barriers. Here, the short wall has a smaller area than the barrier. The walls of the mold 30, mainly short walls, may be rotated to move away from or close to each other to have a certain level of taper. This taper is set to compensate for shrinkage caused by solidification of the molten steel M in the mold 30. The degree of solidification of the molten steel (M) will vary depending on the carbon content, the type of powder (steel cold Vs slow cooling), casting speed and the like depending on the steel type.

The mold 30 has a strong solidification angle or solidifying shell 81 (see FIG. 2) so that the casting extracted from the mold 30 maintains its shape and does not leak molten metal which is still less solidified. It serves to form. The water cooling structure includes a method of using a copper pipe, a method of drilling a water cooling groove in the copper block, and a method of assembling a copper pipe having a water cooling groove.

The mold 30 is oscillated by the oscillator 40 to prevent the molten steel from sticking to the wall of the mold. Lubricants are used to reduce friction between the mold 30 and the casting during oscillation and to prevent burning. Lubricants include splattered flat oil and powder added to the molten metal surface in the mold 30. The powder is added to the molten metal in the mold 30 to become slag, as well as the lubrication of the mold 30 and the casting, as well as the oxidation and nitriding prevention and thermal insulation of the molten metal in the mold 30, and the non-metal inclusions on the surface of the molten metal. It also performs the function of absorption. In order to inject the powder into the mold 30, a powder feeder 50 is installed. The part for discharging the powder of the powder feeder 50 faces the inlet of the mold 30.

The secondary cooling zones 60 and 65 further cool the molten steel that has been primarily cooled in the mold 30. The primary cooled molten steel is directly cooled by the spray 65 spraying water while maintaining the solidification angle by the support roll 60 so as not to deform. Casting solidification is mostly achieved by the secondary cooling.

The drawing device adopts a multidrive method using a plurality of sets of pinch rolls 70 and the like so that the casting can be taken out without slipping. The pinch roll 70 pulls the solidified tip of the molten steel in the casting direction, thereby allowing the molten steel passing through the mold 30 to continuously move in the casting direction.

The cutter 90 is formed to cut continuously produced castings to a constant size. As the cutter 90, a gas torch, a hydraulic shear, or the like can be employed.

FIG. 2 is a conceptual view illustrating the continuous casting machine of FIG. 1 based on the flow of molten steel M. Referring to FIG.

Referring to this figure, the molten steel (M) is to flow to the tundish 20 in the state accommodated in the ladle (10). For this flow, the ladle 10 is provided with a shroud nozzle 15 extending toward the tundish 20. The shroud nozzle 15 extends to be immersed in the molten steel in the tundish 20 so that the molten steel M is not exposed to air and oxidized and nitrided. The case where molten steel M is exposed to air due to breakage of shroud nozzle 15 is called open casting.

The molten steel M in the tundish 20 flows into the mold 30 by a submerged entry nozzle 25 extending into the mold 30. The immersion nozzle 25 is disposed in the center of the mold 30 so that the flow of molten steel M discharged from both discharge ports of the immersion nozzle 25 can be symmetrical. The start, discharge speed, and stop of the discharge of the molten steel M through the immersion nozzle 25 are determined by a stopper 21 installed in the tundish 20 corresponding to the immersion nozzle 25. Specifically, the stopper 21 may be vertically moved along the same line as the immersion nozzle 25 to open and close the inlet of the immersion nozzle 25.

The molten steel M in the mold 30 starts to solidify from the part in contact with the wall surface of the mold 30. This is because heat is more likely to be lost by the mold 30 in which the periphery is cooled rather than the center of the molten steel M. The rear portion along the casting direction of the strand 80 is formed by the non-solidified molten steel 82 being wrapped around the solidified shell 81 in which the molten steel M is solidified by the method in which the peripheral portion first solidifies.

As the pinch roll 70 (FIG. 1) pulls the tip portion 83 of the fully solidified strand 80, the unsolidified molten steel 82 moves together with the solidified shell 81 in the casting direction. The uncondensed molten steel 82 is cooled by the spray 65 for spraying cooling water in the course of the above movement. This causes the thickness of the uncooled steel (82) in the strand (80) to gradually decrease. When the strand 80 reaches a point 85, the strand 80 is filled with the solidification shell 81 in its entire thickness. The solidified strand 80 is cut to a predetermined size at the cutting point 91 and divided into a product P such as a slab.

Here, when the height of the stopper 21 rises in the discharge of the molten steel M discharged from the tundish 20 to the mold 30, the discharge amount of the molten steel M is determined according to the rising degree. By the way, when molten steel is Ca untreated steel, the fused material, such as alumina, adheres to the inner wall of the immersion nozzle 25, and a clogging phenomenon arises in the immersion nozzle 25 by this adhesion. If clogging occurs in the immersion nozzle 25, in order to inject a certain amount of molten steel (M) into the mold 30, it is necessary to raise the height of the stopper 21.

Using this principle, immersion is made using the reference height of the stopper 21, that is, the discharge amount of the molten steel M discharged from the immersion nozzle in a steady state and the actual height of the stopper 21 for discharging the reference amount of molten steel. The degree of clogging of the nozzle 25 can be estimated.

3 is a graph of the discharge amount and the height of the stopper in the immersion nozzle in the steady state. The vertical axis is the height of the stopper (mm), and the horizontal axis is the discharge amount per minute (ton / min) of the molten steel (M). As shown, the height of the stopper 21 and the discharge amount of the molten steel have a relation of a linear function, and the relation is as follows.

[Equation 1]

H 0 = Discharge amount × 7.01 + 3.74

H 0 : Height of the stopper in the normal immersion nozzle (mm)

Discharge amount: ton / min

If nozzle clogging occurs under a constant molten steel discharge amount, the height of the stopper is raised to compensate for the decrease in the opening area of the immersion nozzle 25. In consideration of this phenomenon, the nozzle clogging index is determined by Equation 2.

[Equation 2]

Blockage Index = 1-H 0 / H

H 0 : Height of the stopper in the normal immersion nozzle (mm)

H: Height of stopper in immersion nozzle in blocked state (mm)

4 and 5 are graphs of experimental data confirming whether the above-described blockage index matches the actual blockage degree.

Figure 4 is a graph showing the weight of the ladle, the weight of the tundish, the casting speed and the blockage index over time in the first example of the actual state associated with an embodiment of the present invention, Figure 5 is an embodiment of the present invention In the second example, the graph shows the weight of the ladle, the weight of the tundish, the casting speed and the blockage index over time.

In Fig. 4, reference numeral (a) denotes a line for the amount of molten steel of the ladle over time, reference numeral (b) denotes a line for the amount of molten steel of the tundish over time, and reference numeral (c) corresponds to the time It is a line about casting speed (that is, the meaning of discharge amount of molten steel), and (D) is a line about the blockage index with time.

As shown, it can be seen that in the first example, as time passes, the immersion nozzle is blocked, the casting speed is lowered, and the blockage index is increased. In addition, the blockage index of the final immersion nozzle was 0.69, whereas the degree of blockage of the actual nozzle was 0.70. Therefore, it can be seen that the blockage index described in FIG. 3 accurately estimates the degree of blockage of the actual nozzle.

On the other hand, when the clogging index of the nozzle is 0.70, it is time to replace the nozzle. That is, a lot of nozzles are clogged to maintain high productivity, in which case the immersion nozzle 25 must be replaced. The slope of the line (D) can be used to predict when to replace the nozzle.

In Fig. 5, reference numeral (a) denotes a line for the amount of molten steel of the ladle over time, reference numeral (b) denotes a line for the amount of molten steel of the tundish over time, and reference numeral (c) denotes the time It is a line about casting speed (that is, the meaning of discharge amount of molten steel), and (D) is a line about the blockage index with time.

As shown, in the second example, it can be seen that over time, the immersion nozzle is blocked, the casting speed is lowered, and the blockage index is increased. In addition, the blockage index of the final immersion nozzle was 0.16, whereas the degree of blockage of the actual nozzle was 0.15. Therefore, it can be seen that the blockage index described in FIG. 3 accurately estimates the degree of blockage of the actual nozzle.

On the other hand, when the clogging index of the nozzle is 0.70, it is time to replace the nozzle. That is, a lot of nozzles are clogged to maintain high productivity, in which case the immersion nozzle 25 must be replaced. The slope of the line (D) can be used to predict when to replace the nozzle.

6 is a flowchart illustrating a method of estimating a degree of clogging of an immersion nozzle and a method of estimating immersion nozzle replacement time according to an embodiment of the present invention.

As shown, first, the first height of the stopper with respect to the amount of molten steel discharged through the immersion nozzle in the steady state in the tundish is obtained (S1). Since the first height acquisition has been described with reference to FIG. 3, description thereof will be omitted. Then, the continuous casting process is actually carried out to obtain a second height which is the height of the stopper for discharging the molten steel amount during the actual process, that is, the immersion nozzle is blocked (S3). The blockage index of the immersion nozzle is obtained using the first height and the second height (S5). Since the blockage index has been described above, detailed description thereof will be omitted. Based on the blockage index, the degree of blockage of the immersion nozzle can be estimated based on the blockage index.

On the other hand, when a plurality of the second height is obtained over time, it is possible to obtain the amount of change in the blockage index, thereby, it is possible to measure the nozzle blockage rate (S7). According to the nozzle clogging speed, the clogging index is predicted, and the immersion nozzle replacement time can be estimated based on the predicted clogging index (S9). For example, it is possible to estimate the time when the blockage index reaches 0.70. Then, if the castable time is less than the sum of the casting time of the amount of molten steel remaining in the current ladle and the casting time of the next ladle, it is impossible to take the next ladle, and thus, when the molten steel injection in the current ladle is completed, , The casting is stopped.

The immersion nozzle clogging degree estimation method and the immersion nozzle replacement time estimation method as described above are not limited to the configuration and operation of the embodiments described above. The above embodiments may be configured such that various modifications may be made by selectively combining all or part of the embodiments.

10: ladle 15: shroud nozzle
20: tundish 25: immersion nozzle
30: mold 40: mold oscillator
50: powder feeder 51: powder layer
52: liquid fluidized bed 53: lubricating layer
60: support roll 65: spray
70: pinch roll 80: strand
81: solidified shell 82: unsolidified molten steel
83: tip 85: solidification completion point
87: oscillation mark 88: bulging area

Claims (7)

Obtaining a first height of the stopper for the amount of molten steel discharged through the immersion nozzle in a steady state in a tundish;
Acquiring a second height which is a height of a stopper for discharging the molten steel in the state in which the immersion nozzle is blocked;
Obtaining a blockage index of the immersion nozzle using the first height and the second height; And
And estimating a degree of blockage of the immersion nozzle based on the blockage index.
The method of claim 1,
And the first height is obtained by the following equation.
H 0 [mm] = discharge rate [ton / min] × 7.01 + 3.74
H 0 is the first height.
The method of claim 2,
And said clogging index is obtained by the following equation.
Blockage Index = 1-H 0 / H
H 0 First height (mm)
H: 2nd height (mm)
Obtaining a first height of the stopper for the amount of molten steel discharged through the immersion nozzle in a steady state in a tundish;
Acquiring a plurality of second heights, which are the heights of the stoppers for discharging the molten steel in a state where the immersion nozzles are blocked, over time;
Acquiring a plurality of clogging indexes of the immersion nozzle using the first height and the second height;
Measuring a nozzle clogging speed by using a change amount of the plurality of clogging indexes; And
Predicting the blockage index according to the nozzle clogging speed, and estimating a time for replacing the immersion nozzle based on the predicted blockage index.
The method of claim 4, wherein
And the first height is obtained by the following equation.
H 0 [mm] = discharge rate [ton / min] × 7.01 + 3.74
Provided that H 0 is the first height.
The method of claim 5, wherein
And said clogging index is obtained by the following equation.
Blockage Index = 1-H 0 / H
H 0 First height (mm)
H: 2nd height (mm)
The method of claim 4, wherein
Estimating the blockage index according to the nozzle clogging speed, and estimating when to replace the immersion nozzle based on the predicted blockage index
And a step of estimating when the blockage index becomes 0.70 as a replacement timing of the immersion nozzle.
KR1020100040447A 2010-04-30 2010-04-30 Method for estimating clogging degree of submerged entry nozzle and method for estimating time of changing submerged entry nozzle KR101109450B1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101443586B1 (en) * 2012-09-27 2014-09-23 현대제철 주식회사 Method for continuous-continuous casting
CN107282902A (en) * 2016-04-04 2017-10-24 鞍钢股份有限公司 A kind of replacing options of submersed nozzle

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KR101443585B1 (en) * 2012-07-31 2014-09-23 현대제철 주식회사 Method for estimating clogging degree of submerged entry nozzle
KR101477114B1 (en) * 2012-11-29 2014-12-29 현대제철 주식회사 Method for continuous-continuous casting
KR101654206B1 (en) 2014-11-25 2016-09-05 주식회사 포스코 Apparatus and method for measuring nozzle clogging and method for controlling flow of molten steel using the same
CN110355341A (en) * 2019-07-17 2019-10-22 首钢京唐钢铁联合有限责任公司 A kind of method and device for predicting nozzle blocking degree
CN110883332B (en) * 2019-11-21 2023-08-15 中冶赛迪技术研究中心有限公司 Method and system for online detection of nozzle blockage
CN113084145A (en) * 2021-04-02 2021-07-09 重庆钢铁股份有限公司 Continuous casting tundish nozzle replacing process

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05305408A (en) * 1992-04-28 1993-11-19 Nippon Steel Corp Casting method at the time of lacking in continuous casting
JPH07178525A (en) * 1993-12-24 1995-07-18 Nippon Steel Corp Method for controlling pouring quantity of molten steel for surface layer in continuous casting of double layered steel plate
KR100711439B1 (en) * 2005-12-26 2007-04-24 주식회사 포스코 Apparatus of controlling molten metal level which is robust for periodic disturbance
KR20080113771A (en) * 2007-06-26 2008-12-31 주식회사 포스코 Apparatus for preventing from nozzle clogging, apparatus for continuous casting having the same, method for preventing from nozzle clogging and continuous casting method using it

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05305408A (en) * 1992-04-28 1993-11-19 Nippon Steel Corp Casting method at the time of lacking in continuous casting
JPH07178525A (en) * 1993-12-24 1995-07-18 Nippon Steel Corp Method for controlling pouring quantity of molten steel for surface layer in continuous casting of double layered steel plate
KR100711439B1 (en) * 2005-12-26 2007-04-24 주식회사 포스코 Apparatus of controlling molten metal level which is robust for periodic disturbance
KR20080113771A (en) * 2007-06-26 2008-12-31 주식회사 포스코 Apparatus for preventing from nozzle clogging, apparatus for continuous casting having the same, method for preventing from nozzle clogging and continuous casting method using it

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101443586B1 (en) * 2012-09-27 2014-09-23 현대제철 주식회사 Method for continuous-continuous casting
CN107282902A (en) * 2016-04-04 2017-10-24 鞍钢股份有限公司 A kind of replacing options of submersed nozzle
CN107282902B (en) * 2016-04-04 2018-12-04 鞍钢股份有限公司 A kind of replacing options of submersed nozzle

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