Cooling apparatus for metal strips, heat treatment equipment for metal strips, and method for cooling metal strips

Abstract

An apparatus for cooling a metal strip according to the present invention is used for the purpose of cooling a traveling metal strip; and this apparatus for cooling a metal strip comprises a plurality of nozzles which are each configured so as to spray a cooling medium onto the surface of the metal strip. The ratio La / Ln of the length La of a non-effective collision region in the traveling direction, the non-effective collision region being positioned between a pair of effective collision regions that are adjacent to each other in the traveling direction among the effective collision regions of the plurality of nozzles, to the center-to-center distance Ln of the pair of effective collision regions in the traveling direction is 0.2 to 0.6; and the effective collision regions are areas where the collision density of a liquid, which is contained in the cooling medium sprayed from the nozzles on the surface of the metal strip, on the surface is 50% or more of the maximum value thereof.

Claims

1. A cooling device for cooling a moving metal strip, The metal strip is provided with a plurality of nozzles, each configured to spray a cooling medium onto the surface of the metal strip. Among the effective collision areas of the plurality of nozzles, the ratio La / Ln of the length La of the non-effective collision area in the direction of travel of the metal strip between adjacent pairs of effective collision areas in the direction of travel and the distance Ln between the centers of the pair of effective collision areas in the direction of travel is 0.2 or more and 0.6 or less. The effective impact area is the region in which the impact density of the liquid contained in the cooling medium sprayed from the nozzle onto the surface of the metal strip is 50% or more of the maximum value on the surface. A cooling device for metal strips.

2. The ratio of the length La of the non-effective collision area in the direction of travel to the center-to-center distance Ln La / Ln is between 0.45 and 0.

5. Cooling device for a metal strip according to claim 1.

3. The length Le of each of the pair of effective collision areas in the aforementioned direction of travel is 80 mm or more and 140 mm or less. Cooling device for a metal strip according to claim 1 or 2.

4. The effective collision area has a shape having a first axis along the width direction of the metal strip and a second axis intersecting the first axis. The first axis is longer than the second axis. Cooling device for a metal strip according to claim 1 or 2.

5. The first axis is inclined with respect to the width direction. Cooling device for a metal strip according to claim 4.

6. The angle of the first axis with respect to the width direction is 18 degrees or less. Cooling device for a metal strip according to claim 5.

7. The angle of the first axis with respect to the width direction is 5 degrees or more and 15 degrees or less. Cooling device for a metal strip according to claim 6.

8. The contour of the effective collision area has a shape formed by connecting a pair of semicircular arcs with two straight lines. Cooling device for a metal strip according to claim 4.

9. A furnace for heat-treating metal strips, A cooling device according to claim 1 or 2, configured to cool the metal strip that has been heat-treated in the furnace, A heat treatment facility for metal strips equipped with the following features.

10. A cooling method for cooling a moving metal strip using a cooling device that includes multiple nozzles, The process includes a step of cooling the metal strip by spraying a cooling medium onto the surface of the metal strip from the plurality of nozzles, In the cooling step, the cooling medium is sprayed onto the surface of the metal strip such that the ratio La / Ln of the length La of the non-effective collision area in the direction of travel of the metal strip between a pair of adjacent effective collision areas in the direction of travel of the metal strip, and the distance Ln between the centers of the pair of effective collision areas in the direction of travel of the metal strip, is 0.2 or more and 0.6 or less. The effective impact area is the region in which the impact density of the liquid contained in the cooling medium sprayed from the nozzle onto the surface of the metal strip is 50% or more of the maximum value on the surface. A method for cooling a metal strip.

11. In the cooling step, the cooling medium is sprayed onto the surface of the metal strip from the plurality of nozzles such that the amount of cooling medium sprayed onto the surface of the metal strip per square meter is 500 liters per minute or more. The method for cooling a metal strip according to claim 10.

12. In the cooling step, the cooling medium is sprayed onto the surface of the metal strip at a temperature of 600°C or higher to cool the metal strip to a temperature range of 100°C to 400°C. A method for cooling a metal strip according to claim 10 or 11.

13. In the cooling step, the cooling medium is sprayed onto the surface of the metal strip such that the length Le of the effective collision area in the direction of travel is 80 mm or more and 140 mm or less. A method for cooling a metal strip according to claim 10 or 11.

14. In the cooling step, the cooling medium is sprayed onto the surface of the metal strip such that the effective impact area has a first axis along the width direction of the metal strip and a second axis intersecting the first axis, and the first axis is longer than the second axis. A method for cooling a metal strip according to claim 10 or 11.

15. In the cooling step, the cooling medium is sprayed onto the surface of the metal strip with the first axis inclined with respect to the width direction. The method for cooling a metal strip according to claim 14.

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