Apparatus and method for predicting slab quality

1. An apparatus for predicting slab quality comprising:

a plurality of temperature sensors located in a plurality of regions around a top side of a mold receiving molten steel at a height corresponding to a height of a meniscus of the molten steel in the mold, and detecting a meniscus temperature of the molten steel;

a meniscus flow detecting unit creating a meniscus flow pattern using the meniscus temperatures at the plurality of regions, which are detected by the plurality of temperature sensors;

a data storage unit storing the meniscus flow pattern and quality data of a plurality of slabs produced accordingly;

a slab quality predicting unit predicting the slab quality of an individual slab by comparing the meniscus flow pattern created by the meniscus flow detecting unit for the individual slab to the stored meniscus flow pattern and quality data;

wherein the meniscus flow detecting unit creates a 3-dimensional (3D) meniscus flow image according to the meniscus temperatures and a 2-dimensional (2D) meniscus flow pattern from the 3D image; and

the 3D meniscus flow image is created based on a vertical distance between each temperature sensor and the meniscus, which is calculated by applying the temperatures measured by each temperature sensor to the following Equation (1),

α

×

2.5

×

Q

=

(

K

slag

d

slag

+

K

cu

d

cu

)

×

(

T

steel

-

T

1

)

⁢

⁢

d

cu

=

d

1

2

+

d

2

2

(

1

)

where α denotes a correction coefficient using an eddy current sensor, Q denotes a real time heat flux using a temperature difference at an input/output side of the mold, K slag denotes a heat transfer coefficient of a slag, K cu denotes a heat transfer coefficient of the mold, d slag denotes the thickness of a slag layer, d cu denotes a diagonal distance between the molten steel contacting a short side of the mold and the temperature sensor, T steel denotes a real time temperature of the molten steel, T 1 denotes a real time temperature of the temperature sensor, d 1 denotes a vertical distance between the temperature sensor and the meniscus, and d 2 denotes a distance between a side surface of the mold and a tip of the temperature sensor.

2. The apparatus of claim 1 , further comprising a display unit displaying the meniscus flow pattern and the consequent slab quality to a user.

3. The apparatus of claim 1 , wherein the temperature sensors are installed at an identical height on the top side of the mold.

4. The apparatus of claim 3 , wherein the temperature sensors are installed at a height in a range of 4.5 mm to 9.5 mm from the meniscus.

5. The apparatus of claim 1 , wherein the 3D meniscus flow image is created using temperature differences between the plurality of regions measured through the temperature detecting means.

6. The apparatus of claim 1 , wherein after provision of the molten steel to the mold is completed, the meniscus flow pattern is created at least once.

7. The apparatus of claim 1 , wherein the data storage unit performs matching of the meniscus flow pattern with at least one selected from presence or not of defects, defect positions, and defect shapes of the consequent slab and stores the matched results.

8. The apparatus of claim 1 , wherein the display unit displays at least any one piece of information provided from the temperature sensors, the meniscus flow detecting unit, the data storage unit, and the slab quality predicting unit.

9. A method of predicting slab quality comprising:

installing a plurality of temperature sensors in a plurality of regions around a top side of a mold receiving molten steel at a height corresponding to a height of a meniscus of the molten steel in the mold, and detecting a meniscus temperature of the molten steel;

creating a meniscus flow pattern using the meniscus temperatures at the plurality of regions, which are detected by the plurality of temperature sensors;

comparing pre-stored meniscus flow pattern data with a current meniscus flow pattern in the mold; and

predicting the slab quality of the slab associated with the current meniscus flow pattern based on the comparison,

wherein creating the meniscus flow pattern includes creating a 3-dimensional (3D) meniscus flow image according to the meniscus temperatures and a 2-dimensional (2D) meniscus flow pattern from the 3D image, and

the 3D meniscus flow image is created based on a vertical distance between each temperature sensor and the meniscus, which is calculated by applying the temperatures measured by each temperature sensor to the following Equation (1),

α

×

2.5

×

Q

=

(

K

slag

d

slag

+

K

cu

d

cu

)

×

(

T

steel

-

T

1

)

⁢

⁢

d

cu

=

d

1

2

+

d

2

2

(

1

)

where α denotes a correction coefficient using an eddy current sensor, Q denotes a real time heat flux using a temperature difference at an input/output side of the mold, K slag denotes a heat transfer coefficient of a slag, K cu denotes a heat transfer coefficient of the mold, d slag denotes the thickness of a slag layer, d cu denotes a diagonal distance between the molten steel contacting a short side of the mold and the temperature sensor, T steel denotes a real time temperature of the molten steel, T 1 denotes a real time temperature of the temperature sensor, d 1 denotes a vertical distance between the temperature sensor and the meniscus, and d 2 denotes a distance between a side surface of the mold and a tip of the temperature sensor.

10. The method of claim 9 , further comprising storing a plurality of meniscus flow pattern data and a plurality of slab quality data accordingly produced.

11. The method of claim 10 , further comprising displaying the meniscus flow pattern and the consequent slab quality to a user.

12. The method of claim 10 , further comprising, when the current meniscus flow pattern is not matched with the meniscus flow pattern data, making the current meniscus flow pattern and the consequent slab quality as data and storing the data.