KR101477114B1 - Method for continuous-continuous casting - Google Patents

Abstract

Calculating an ejection performance remaining time (RT) by an immersion nozzle in operation using a predetermined reference value, a clogging index IDc of the immersion nozzle, and a nozzle clogging speed Vc; calculating the ejection amount D of the molten steel, Calculating an estimated annual casting time ET using the remaining amount Q of the tundish, the standard amount of molten steel R taken in the ladle waiting for operation and the number of ladles N waiting for operation, (Df) of the molten steel and a discharge amount ( _Df ) of the molten steel after determining the possibility of completion of the continuous casting by comparing the continuous casting remaining time (RT) with the expected casting expected casting time And determining the upper limit value (D _h ) and resetting the discharge amount (D) of molten steel.

Description

{METHOD FOR CONTINUOUS-CONTINUOUS CASTING}

The present invention relates to a continuous casting method for determining the possibility of completion of continuous casting in accordance with the degree of clogging of an immersion nozzle in continuous casting and resetting the discharge amount of molten steel to proceed the performance process.

In general, a continuous casting machine is a machine that is produced in a steelmaking furnace, receives molten steel transferred to a ladle in a turndish, and supplies it as a casting mold for a continuous casting machine to produce a slab of a predetermined size.

The continuous casting machine includes a ladle for storing molten steel, a tundish, and a continuous casting machine mold for initially cooling the molten steel to be cast from the tundish to form a casting having a predetermined shape, and a casting mold connected to the casting mold, And a plurality of pinch rollers for moving the pinch rollers.

In other words, molten steel introduced from the ladle and the tundish is formed into a casting such as a slab, a bloom, or a billet having a predetermined width and thickness in the mold and is conveyed through the pinch roller.

Related Prior Art Korean Patent Laid-Open Publication No. 2009-71221 (published on Jul. 1, 2009, entitled "Method and apparatus for predicting clogging of an immersion nozzle") is available.

The present invention relates to a method for continuously casting continuous casting, comprising the steps of: calculating a remaining playing time and an estimated casting time of the continuous casting, determining the possibility of completion of the continuous casting according to the degree of clogging of the immersion nozzle, resetting the discharge amount of the molten steel, To provide a playing method.

The technical objects to be achieved by the present invention are not limited to the above-mentioned technical problems.

In order to accomplish the above object, the present invention provides a method of playing a continuous performance, comprising the steps of: determining a continuous playing time (RT) by an immersion nozzle in operation using a preset reference value, a clogging index (IDc) of the immersion nozzle, , The amount of molten steel discharged (D), the remaining amount of tundish (Q) in operation and the tundish, the standard amount of molten steel (R) taken in the ladle waiting for operation, and the number of ladles , Determining an expected casting time (ET) for the annual performance, comparing the estimated remaining casting time (RT) with the estimated casting time (ET) (D _f ) of molten steel and a discharge amount upper limit value (D _h ), and resetting the discharge amount (D) of molten steel.

Specifically, the soft play remaining time RT can be calculated by the following relational expression.

Relation

The predetermined reference value is 0.70, and the clogging index (IDc) is obtained by the following relational expression (1), and the clogging rate (Vc) can be obtained by the following relational expression (2).

Relationship 1

(Where Hs is the theoretical height (mm) of the stopper and Hw is the operating height (mm) of the stopper.)

Relation 2

(Herein, the clogging index IDc of the immersion nozzle is a difference value at two selected points in the clogging index IDc of a plurality of immersion nozzles, and the point A may be a difference value between the two points.)

Theoretical height of the stopper (Hs) can be calculated to an initial discharge rate of the initial height (H ₀₎ of (D ₀₎ and the stopper assigned to the relational expression.

Relation

The expected casting time ET can be obtained by the following relationship.

Relation

(Where Q is the remaining amount of ladle and tundish in operation, R is the standard amount of molten steel taken in ladle waiting for operation, and N can be the number of ladle in waiting for operation).

Wherein the step of determining the probability of completion of the annual performance is performed by maintaining the discharge amount (D) of the molten steel when the estimated casting time ET of the annual performance is equal to or less than the annual performance remaining time RT, If the remaining time (RT) is exceeded, it can be judged that the completion of the annual performance is impossible.

The step of resetting the molten steel discharge amount (D) includes the steps of: determining a remaining playing time (RT), a remaining amount of the ladle and tundish (Q) in operation, a standard amount of molten steel (R) taken in the ladle waiting for operation, The appropriate discharge amount (D _f ) can be obtained by using the number of ladles (N).

The discharge amount upper limit value (D _h ) can be obtained by multiplying the maximum peripheral velocity (VC), the slab width, the slab thickness, and the molten steel density.

Comparing the proper flow rate (D _f) and the discharge rate of the upper limit value (D _h), proper flow rate (D _f) discharge amount of the discharge rate of the upper limit value (D _h) has calculated the proper flow rate (D _f) not more than molten steel (D ) the adjustment, if the proper flow rate (D _f) is greater than the discharge amount upper limit value (D _h) is to reset the flow rate (D) of adjusting the flow rate (D) of molten steel in the calculation the discharge rate of the upper limit value (D _h) the molten steel Step < / RTI >

The appropriate discharge amount (D _f ) is obtained by the following relational expression (1), and the discharge amount upper limit value (D _h ) can be obtained by the following relational expression (2).

Relationship 1

(Where Q is the remaining amount of ladle and tundish in operation, R is the standard amount of molten steel taken in ladle waiting for operation, and N can be the number of ladle in waiting for operation).

Relation 2

(Here, the maximum peripheral speed (VC) may be a unit of m / min.)
Wherein the maximum peripheral velocity (VC; m / min) is calculated by the following relational expression.
Relation

(Wherein? ₀ is 2.364 to 2.484 and? ₁ is 0.67 to 0.80, S is the solidification shell thickness (mm), and HF is the mold heat transfer amount (W / m ² )

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As described above, according to the continuous playing method of the present invention, it is possible to estimate the degree of clogging of the immersion nozzle to determine in advance the probability of completion of the continuous performance, and to reset the discharge amount of the molten steel to proceed with the performance process.

In addition, by this, the continuous casting process is stopped unexpectedly, so that the ladle that is waiting for the operation is prevented from being moved or the process of reprocessing the molten steel accommodated in the ladle is prevented from being performed, and productivity can be expected to be improved.

1 is a side view showing a continuous casting machine according to one embodiment of the present invention.
Fig. 2 is a conceptual diagram for explaining the continuous casting machine of Fig. 1 centered on the flow of molten steel M. Fig.
3 is a flow chart for explaining an annual playing method which is an embodiment of the present invention.
FIG. 4 is a flowchart for explaining the calculation process of the soft play remaining time RT in FIG.
5 is a flowchart for explaining the step of resetting the discharge amount of the molten steel of FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same components are denoted by the same reference symbols whenever possible. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

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

Continuous casting is a casting process in which a molten metal is continuously cast into a bottomless mold while continuously drawing a steel ingot or steel ingot.

The shape of a continuous casting machine is classified into a vertical type and a vertical bending type. In Figs. 1 and 2, a vertical bending-like shape is illustrated.

1, the continuous casting machine may include a ladle 10 and a tundish 20, a mold 30, a secondary cooling stand 60 and 65, a pinch roll 70, and a cutter 90 have.

A tundish 20 is a container for receiving molten metal from a ladle 10 and supplying molten metal to a mold 30. The ladles 10 are provided in pairs to alternately receive molten steel and supply the molten steel to the tundish 20. In the tundish 20, the supply rate of the molten metal flowing into the mold 30 is controlled, the molten metal is distributed to each mold 30, the molten metal is stored, and the slag and the nonmetallic inclusions are separated.

Mold 30 is typically made of water-cooled copper and allows the molten steel taken to be first cooled. The mold 30 has a pair of structurally opposed faces open to form a hollow portion for receiving molten steel. In the case of manufacturing the slab, the mold 30 includes a pair of barriers and a pair of end walls connecting the barriers. Here, the end wall has a smaller area than the barrier. The walls, mainly the walls, of the mold 30 can be rotated to be away from or close to each other to have a certain level of taper. This taper is set to compensate for the shrinkage due to the solidification of the molten steel M in the mold 30. The degree of solidification of the molten steel (M) varies depending on the carbon content according to the steel type, the kind of the powder (strong cold type Vs and cold type), the casting speed and the like.

The mold 30 is formed of a solidified shell 81 or a solidified shell 81 that retains the shape of the casting 80 pulled out of the mold 30, And the like. The water-cooling structure includes a method using a copper tube, a method of water-cooling the copper block, and a method of assembling a copper tube having a water-cooling groove.

The mold 30 is oscillated by the oscillator 40 to prevent the molten steel from sticking to the wall surface of the mold 30. A lubricant is used to reduce the friction between the mold 30 and the solidification shell 81 during oscillation and to prevent burning. As the lubricant, there is oil to be sprayed 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 so that the lubricating of the mold 30 and the solidifying shell 81 as well as the prevention and nitriding of the molten metal in the mold 30 and the warming, It also functions to absorb non-metallic inclusions. A powder feeder 50 is installed to feed the powder into the mold 30. The portion of the powder feeder 50 for discharging the powder is directed to the inlet of the mold 30.

The secondary cooling bands 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 the coagulation angle is kept unchanged by the support roll 60. Most of the solidification of the cast slab 80 is achieved by the secondary cooling.

Fig. 2 is a conceptual diagram for explaining the continuous casting machine of Fig. 1 centered on the flow of molten steel M. Fig.

Referring to this figure, the molten steel M flows into the tundish 20 while being 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 into the molten steel in the tundish 20 so that the molten steel M is not exposed to the air to be oxidized and nitrided. The case where the molten steel M is exposed to air due to breakage of the shroud nozzle 15 or the like is referred to as open casting.

The molten steel M in the tundish 20 is caused to flow into the mold 30 by the submerged entry nozzle 25 extending into the mold 30. The immersion nozzle 25 is disposed at the center of the mold 30 so that the flow of the molten steel M discharged from both the discharge ports of the immersion nozzle 25 can be made symmetrical. The start, discharge speed and interruption of the discharge of the molten steel M through the immersion nozzle 25 are determined by a stopper 21 provided on the tundish 20 in correspondence with the immersion nozzle 25. [ Specifically, the stopper 21 can be vertically moved along the same line as that of the immersion nozzle 25 so as to open and close the inlet of the immersion nozzle 25.

Molten steel (M) in the mold (30) starts to solidify from a portion in contact with the wall surface of the mold (30). This is because the periphery of the molten steel M is liable to lose heat by the water-cooled mold 30. The rear portion along the casting direction of the cast slab 80 is formed into a shape in which the non-solidified molten steel 82 is wrapped in the solidifying shell 81 by the method in which the peripheral portion first coagulates.

The non-solidified molten steel 82 moves together with the solidifying shell 81 in the casting direction as the pinch roll 70 (Fig. 1) pulls the tip end portion 83 of the fully-solidified cast slab 80. The non-solidified molten steel (82) is cooled by the spray (65) spraying the cooling water in the course of the above movement. This causes the thickness of the non-solidified molten steel (82) to gradually decrease in the cast steel (80). When the cast slab 80 reaches the solidification complete point 85, the cast slab 80 is filled with the solidified shell 81 as a whole. The solidification casting 80 having been solidified is cut to a predetermined size at the cutting point 91 and is divided into a slab P such as a slab or the like.

1, the apparatus including the support roll 60, the spray 65, and the pinch roll 70 is also referred to as a strand.

When the height of the stopper 21 is increased, the discharge amount D of the molten steel is determined according to the degree of the upward movement of the stopper 21. However, when the molten steel is Ca-untreated steel, fused materials such as alumina adhere to the inner wall of the immersion nozzle 25, and clogging occurs in the immersion nozzle 25 due to the adhesion. When the immersion nozzle 25 is clogged, the height of the stopper 21 must be increased in order to inject a certain amount of molten steel into the mold 30.

Using this principle, the reference height of the stopper 21, that is, the discharge amount D of the molten steel discharged from the immersion nozzle 25 in the steady state and the operation height Hw of the stopper 21 for discharging the molten steel in the reference amount It is possible to estimate the clogging degree of the immersion nozzle 25 and to estimate the soft play remaining time RT according to the degree of clogging of the immersion nozzle 25. [

3 is a flow chart for explaining an annual playing method which is an embodiment of the present invention.

According to the present flowchart, in order to calculate in advance the time at which the tune ending time ends, the tune playing remaining time RT is calculated first (S10)

Specifically, the reference value, the clogging index IDc of the immersion nozzle, and the nozzle clogging speed Vc are substituted into the following relational expression 1 to calculate the remaining running time (RT) during operation.

Relationship 1

Here, the reference value is a threshold constant value of the predetermined immersion nozzle clogging index IDc, and the clogging index IDc of the immersion nozzle is the clogging index IDc of the immersion nozzle calculated at a selected point in time during operation. At this time, the threshold constant value of the immersion nozzle clogging index IDc, which is a reference value, is usually calculated based on the immersion nozzle clogging index IDc calculated at the time when it is determined that the immersion nozzle 25 is excessively clogged, Lt; / RTI > The nozzle clogging velocity Vc is a change amount of the immersion nozzle clogging index IDc with respect to the time at the two selected time points.

4 is a flowchart illustrating a process of calculating the continuous play duration RT of the stopper 21 with respect to the discharge amount D of molten steel delivered through the immersion nozzle 25 in the steady state in the tundish 20, calculates the theoretical height (Hs). (S11) here, the initial height (H ₀₎ of the stopper initial discharge amount of the theoretical height (Hs) is previously measured molten steel 21 (D ₀₎ and the stopper (21) And substituting the discharge amount D of the molten steel conveyed through the immersion nozzle 25 at the current measurement time into the following equation (2). At this time, the discharge amount (D) of molten steel at the present measurement time is adjusted to a constant amount to keep the continuous casting speed constant. In addition, since the casting speed varies depending on the type of cast steel, the discharge amount D of molten steel is set differently depending on the type of cast steel.

Relation 2

Here, Hs is the theoretical height of the stopper 21, the flow rate (D) is a flow rate (D) of molten steel in the current measurement time point, the initial flow rate (D ₀₎ is a flow rate (D) of the molten steel at an initial time of continuous casting And H ₀ is the height of the stopper 21 at the initial stage of continuous casting.

The operation height Hw which is the height of the stopper 21 for discharging the same amount of molten steel as the discharge amount D in a state where clogging occurs in the immersion nozzle 25 during casting while actually performing the continuous casting process, (S12). At this time, the operation height Hw of the stopper is repeatedly measured to obtain a measurement value of the operation height Hw of the plurality of stoppers. The reason for measuring a plurality of operating heights (Hw) of the stopper is that the height of the stopper continuously changes over time during operation, so that the operating height of the appropriate stopper among the height Hw of the stopper Hw are selected to increase the reliability of the immersion nozzle clogging index IDc and the nozzle clogging speed Vc. On the other hand, the method of measuring the operating height Hw of the stopper is the same as the method of measuring the initial height of the stopper 21 described above.

Next, the clogging index IDc of the plurality of immersion nozzles is obtained using the calculated theoretical height Hs of the stopper 21 and the measured height Hw of the plurality of stoppers previously calculated (S13) The clogging index IDc of the immersion nozzle is set such that the ratio between the theoretical height of the steady-state stopper 21 and the operating height of the clogged-state stopper 21 is set to be the same as the theoretical height of the steady-state stopper 21, The clogging index IDc of the immersion nozzle is determined by the following equation (3): " (1) "

Relation 3

Here, IDc is the immersion nozzle clogging index IDc, Hs is the theoretical height (mm) of the stopper, and Hw is the operating height (mm) of the stopper.

When a plurality of immersion nozzle clogging indices IDc are obtained as described above, the nozzle clogging speed Vc is calculated using the clogging index IDc of the plurality of immersion nozzles thus obtained and a plurality of time points. (S14)

The nozzle clogging speed Vc is calculated as a change amount of the immersion nozzle clogging index IDc with time, and is determined in detail by the following relationship (4).

Relation 4

Here, the clogging index IDc of the immersion nozzle is a difference value at two selected points in the clogging index IDc of a plurality of immersion nozzles, and the point? Is a time between two points selected at the time of calculation.

Namely, the dumping nozzle ID of the immersion nozzle and the nozzle clogging speed Vc thus determined are substituted into the above-mentioned relational expression 1 together with the predetermined reference value 0.7 to determine the soft play remaining time (RT; Remaining (S10)

Next, the predicted casting time (ET) during the operation is calculated. (S20)

Specifically, the discharge amount D of molten steel, the remaining amount Q of the ladle and the tundish in operation, the number of ladles N waiting for operation, and the standard amount of molten steel R taken in the ladle waiting for operation are expressed by the following relational expression 5 To calculate an estimated annual casting casting time ET.

Relation 5

That is, the sum of the number of ladles (N) waiting for operation in the remaining amount (Q) of the ladle and the tundish in operation and the standard molten steel amount (R) The predicted casting time ET is calculated by dividing the amount of molten steel by the discharge amount per time D to be dispensed at that time and ending the casting period during the current operation.

Next, the preset reference value, the stamper index IDc of the immersion nozzle 25, the soft play remaining time RT calculated through the nozzle clogging speed Vc, the discharge amount D of molten steel, the running ladle and the tundish (N) of the ladle waiting for operation and the estimated casting time (ET) calculated through the standard amount of molten steel (R) taken in the ladle waiting for operation are compared with each other, (S30)

If the estimated casting time ET is less than or equal to the annual performance remaining time RT, the current discharge amount D is maintained (S40). If the estimated performance casting time ET is longer than the annual performance remaining time RT, It is determined that the completion of the performance is impossible (S50)

Subsequently, when it is determined that the completion of the continuous casting is impossible, the discharge amount D of molten steel is reset (S50)

The resetting of the discharge amount D of the molten steel is carried out in accordance with the flow chart of Fig. 5 by first determining the remainder playing time RT, the remaining amount Q of the running ladle and tundish, the number of ladles N waiting for operation, to a standard amount of molten steel (R) to take a waiting ladle substituted into equation 6 to calculate the optimum flow rate (D _f). (S51)

Relation 6

Specifically, the value obtained by multiplying the number of ladles (N) waiting for operation in the remaining amount (Q) of the ladle and tundish currently operating and the standard amount of molten steel (R) taken in the ladle waiting for operation is added, The total amount of molten steel is obtained and divided by the annual play remaining time (RT) calculated in the above-mentioned relational expression 1 to determine the appropriate discharge amount (D _f ).

Subsequently, the maximum flow rate (VC), the slab width, the slab thickness, and the molten steel density are substituted into the following relational expression 7 to calculate the discharge amount upper limit value D _h (S52)

Relation 7

Here, the discharge amount upper limit value D _h is calculated by multiplying the maximum peripheral velocity VC, the slab width, the slab thickness, and the molten steel density. The upper limit of the discharge amount (D _h ) may vary depending on the type of steel.

Here, the maximum peripheral velocity (VC) is a unit of m / min. The maximum peripheral velocity (VC) can be calculated by substituting the solidification shell thickness and the mold heat quantity value into the following relational expression (8).

Relation 8

Here, α ₀ is 2.364 to 2.484, α ₁ is 0.67 to 0.80, S is the solidification shell thickness (mm), and HF is the mold heat quantity (W / m ² ).

In order to have α ₀ and α ₁ in the above range, the superheat degree of the tundish in the present invention is in the range of 10 to 40 ° C., and the values of α ₀ and α ₁ become smaller as the superheat degree of the tundish increases. In the above equation (5), α ₀ and α ₁ have 2.414 and 0.726, respectively, when the superheat degree of the tundish is 30 ° C.

At this time, the thickness of the solidified shell may be in the range of 10 to 14 (mm). This range is the stable range of the solidification shell that can be cast at the maximum peripheral speed without breakout. In an embodiment of the present invention, a more preferred solidification shell thickness may be 12 (mm). If the thickness of the solidified shell is less than 12 (mm), the possibility of breaking-out is increased according to the operating condition. If the thickness is more than 12 (mm)

At this time, the mold heat transfer amount (HF) is calculated by dividing the mold cooling water flow rate, the mold cooling water density, the cooling capacity of the cooling water, the mold cooling water temperature difference at the mold inlet side and the outlet side, The mold length and the mold width which are in contact with each other.

Therefore, the heat transfer amount (HF) in the mold is derived as the following equation (9) using the values of the measured or determined operating parameters.

Relation 9

는 냉각수 밀도이고,

는 냉각수 열용량이고,

는 몰드 입구측과 출구측의 냉각수 온도 차이이고,

은 용강과 접촉하는 몰드의 길이이고, W는 몰드의 폭이다.Here, F is the flow rate of the cooling water circulated and cooled by the mold,

Is the cooling water density,

Is the cooling water heat capacity,

Is the cooling water temperature difference between the mold inlet side and the outlet side,

Is the length of the mold in contact with molten steel, and W is the width of the mold.

That is, the discharge amount upper limit value D _h is calculated using the calculated maximum peripheral velocity VC, the slab width, the slab thickness, and the molten steel density.

Next, the appropriate discharge amount (D _f ) calculated in the previous step is compared with the discharge amount upper limit value (D _h ) (S53)

At this time, if the appropriate discharge amount D _f is compared with the discharge amount upper limit value D _h and the appropriate discharge amount D _f is not more than the discharge amount upper limit value D _h , the discharge amount D of molten steel is calculated as the calculated appropriate discharge amount D _f , and the adjusting (S54), if the proper flow rate (D _f) is more than the upper limit flow rate (D _h), adjust the flow rate (D) of the molten steel flow rate with the calculated upper limit value (D _h). (S55)

When adjusting the discharge amount (D) of molten steel to the discharge amount upper limit value (D _h ), the remaining amount is present after the end of the continuous performance, so that the number of ladles in the waiting queue is decreased and the performance process is adjusted so that no residue is generated.

As a result, the continuous casting process is stopped unexpectedly, so that the ladles that are waiting for the operation are prevented from being moved or the process of reprocessing the molten steel accommodated in the ladle is prevented from being performed, and productivity can be expected to be improved.

The above-described continuous playing method is not limited to the configuration and operation of the above-described embodiments. The embodiments may be configured so that all or some of the embodiments may be selectively combined so that various modifications may be made.

10: Ladle 15: Shroud nozzle
20: Tundish 21: Stopper
25: immersion nozzle 30: mold
40: Mold oscillator 50: Powder feeder
60: Support roll 65: Spray
70: pinch roll 80: performance cast
81: Solidification shell 82: Non-solidified molten steel
83: tip portion 85: solidified point
90: Cutter 91: Cutting point

Claims (9)

Calculating the soft play remaining time (RT) by the immersion nozzle during operation using the preset reference value, the clogging index (IDc) of the immersion nozzle, and the nozzle clogging speed (Vc);
Using the discharge amount (D) of molten steel, the amount of remaining tundish (Q) of the running ladle and the tundish, the amount of standard molten steel (R) taken in the ladle waiting for operation, Calculating a time (ET);
Comparing the soft play remaining time (RT) with the soft play expected casting time (ET) to judge the completion probability of the soft play; And
And resetting the discharge amount (D) of molten steel by determining an appropriate discharge amount (D _f ) and a discharge amount upper limit value (D _h ) of the molten steel after determining the possibility of completion of the continuous casting,
The soft play remaining time (RT) is calculated by the following relational expression,
Relation

Wherein the predicted casting time ET is calculated by the following equation.
Relation

Where Q is the remaining amount of ladle and tundish in operation, R is the standard amount of molten steel taken in the ladle waiting for operation, N is the number of ladle in waiting for operation, and the discharge amount (TON / min) Discharge amount)
delete The method according to claim 1,
Wherein the predetermined reference value is 0.70, the clogging index (IDc) is obtained by the following relational expression (1), and the clogging speed (Vc) is obtained by the following relational expression (2).
Relationship 1

(Where Hs is the theoretical height (mm) of the stopper and Hw is the operating height (mm) of the stopper)
Relation 2

(Where the clogging index IDc of the immersion nozzle is the difference value at two selected points in the clogging index IDc of the plurality of immersion nozzles and the point A is the difference value of the two points)
The method of claim 3,
Theoretical height (Hs) of the stopper is a discharge rate (D), the initial flow rate (D ₀₎ and opened to Play calculated to the initial height (H ₀₎ of the stopper by substituting the equation.
Relation

Here, the discharge amount (D: TON / min) is the discharge amount of molten steel at the present point in time, and the initial discharge amount (D0: TON / min)
delete The method according to claim 1,
Wherein the step of determining the probability of completion of the annual performance includes:
When the estimated casting time ET of the continuous casting is equal to or shorter than the continuous casting remaining time RT, the casting amount D of the molten steel is maintained. If the estimated casting casting time ET exceeds the open casting remaining time RT, Is determined to be impossible.
The method according to claim 1,
The step of resetting the discharge amount (D)
The optimum discharge amount (D) is calculated by using the remaining playing time RT, the remaining amount Q of the running ladle and tundish, the standard amount of molten steel R taken in the ladle waiting for operation, _f );
Obtaining a maximum discharge amount (D _h ) by multiplying the maximum peripheral velocity (VC), the slab width, the slab thickness, and the molten steel density;
The appropriate flow rate (D _f) and the discharge rate of the upper limit value (D _h) as compared to, appropriate flow rate (D _f) a discharge amount upper limit value (D _h) has calculated the proper flow rate (D _f) to adjust the flow rate of the molten steel not more than a; and, when the proper flow rate (D _f) is greater than the discharge amount upper limit value (D _h), the method comprising: resetting the discharge amount (D) of adjusting the flow rate (D) of molten steel in the calculation the discharge rate of the upper limit value (D _h) the molten steel Included playing method.
The method of claim 7,
Wherein the optimum discharge amount (D _f ) is obtained by the following relational expression (1), and the discharge amount upper limit value (D _h ) is obtained by the following relational expression (2).
Relationship 1

(Where Q is the remaining amount of the ladle and tundish in operation, R is the standard amount of molten steel taken in the ladle waiting for operation, and N is the number of ladle in operation waiting)
Relation 2

(Where the maximum peripheral speed VC is a unit of m / min)
The method of claim 7,
Wherein the maximum peripheral velocity (VC; m / min) is calculated by the following relational expression.
Relation

(Wherein? ₀ is 2.364 to 2.484 and? ₁ is 0.67 to 0.80, S is the solidification shell thickness (mm), and HF is the mold heat transfer amount (W / m ² )

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