JPH04279260A - Nozzle for cooling roll in continuous casting - Google Patents

Abstract

PURPOSE:To provide a nozzle for cooling a roll, by which the equipment scale is restrained to the min. limit and the maintenance man-hour is reduced and efficiently executed at a low cost, used to the outer cooling of roll as extending measure for service life of supporting for conveying a cast slab in continuous casting. CONSTITUTION:Three injecting holes for injecting atomized coolant are arranged in the nozzle 1 for cooling the roll, and one in these cools the cast slab 3 from gap between the two supporting rolls 2, 2 at front and rear parts for conveying the cast slab and the rest two in these cool the two supporting rolls 2, 2 at front and rear parts. Then, by cooling the cast slab 3 in the continuous casting and the supporting rolls 2 for conveying with one nozzle 1 for cooling the roll at the same time, the equipment scale is made to the min. limit. Further, the atomizing coolant from the injecting holes 4 executes efficient outer cooling of the roll by the uniform injection toward vertical and width direction to the cast slab 3 and the injection spreading toward axial direction of the supporting rolls 2.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is a roll that sprays coolant onto the slab and supporting roll in order to cool the conveying support roll which is used for conveying the slab in a continuous casting machine and is subjected to a large heat load. This relates to cooling nozzles.

0002

2. Description of the Related Art Molten metal injected into a mold in continuous casting is cooled by the mold and becomes a slab with a certain solidified shell. Thereafter, this cast slab is drawn out while being cooled by spraying within a group of support rolls, and after completely solidified, it is cut into a predetermined length.

[0003] The temperature of the slab during the cooling process is controlled at 600 to 800°C, taking into consideration the surface properties of the slab. Therefore, a large thermal load is applied to the support rolls that support the slab. For this reason, in direct rolling, it has become a common technique to cool the inside of the support roll with water and to perform mist cooling from the outside of the support roll.

As an example of applying this conventional technology to suit continuous casting, as shown in Japanese Patent Application Laid-Open No. 1-237063, this support roll is applied from the upstream side of the support roll that conveys the continuously cast slab. By spraying a mist-like coolant onto the surface of the slab just before it contacts the rolls, a low-temperature thin layer region is formed in which the cooling part of the slab can recuperate more than 90% of its heat after passing through the support rolls until it reaches the next cooling part. A method has been proposed.

[0005]

[Problems to be Solved by the Invention] However, in actual continuous casting machines, it is common to cool the supporting rolls using an internal cooling method, and the roll cooling using an external cooling method as in the previously proposed technology is still common. It has not changed.

[0006] Furthermore, when newly installing the roll cooling equipment of this conventionally proposed technology, cooling nozzles for cooling the front and rear support rolls and cooling nozzles for cooling the slab are required. etc., it requires a large amount of investment for equipment, and has the disadvantage that the increased number of maintenance steps due to the increased equipment increases.

[0007] This invention was devised in view of the above-mentioned circumstances, and its purpose is to minimize the scale of equipment for external cooling of rolls, which is carried out as a measure to extend the life of support rolls for conveying slabs in continuous casting. It is an object of the present invention to provide a roll cooling nozzle for continuous casting that can be performed efficiently at low cost with fewer maintenance steps.

[0008]

[Means for Solving the Problems] As shown in FIG. 1A, the roll cooling nozzle according to the present invention has three injection ports 4 for spraying a sprayed coolant. As shown in FIGS. 1B and 1C, one of them cools the slab 3 from between the two front and rear support rolls 2, 2 for conveying the slab. The remaining two rollers are used to cool the two supporting rollers 2, 2. In this way, one roll cooling nozzle 1 can simultaneously cool the slab 3 in continuous casting and the support roll 2 for conveying the slab.

The three injection ports 4 are configured to form parallel fan-shaped spray streams. Further, the sprayed coolant from each injection port 4 is made to have a uniform flow rate distribution in its spread angle direction. Note that flow characteristics in the width direction and longitudinal direction of the slab 3 in the roll cooling nozzle 1 of the present invention are shown in FIGS. 3 and 4.

The sprayed coolant from the central injection port 4 is sprayed perpendicularly to the slab 3 as shown in FIG. Apply uniform cooling in the width direction of 3. Furthermore, the sprayed coolant from the injection ports 4, 4 on both sides of the central injection port 4 spreads in the axial direction of the support roll 2, as shown in FIGS. 1(B) and (C). It has a spray angle that provides roll cooling.

According to the roll cooling nozzle 1 of the present invention having the above-mentioned characteristics, there is no need to increase the number of nozzles for cooling, so there is no need to change the conventional nozzle piping, and maintenance is required. It is now possible to externally cool the nozzle to extend the life of the roll while keeping the number of man-hours the same as before.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS A roll cooling nozzle for continuous casting according to the present invention will be explained below with reference to the drawings.

A roll cooling nozzle 1 (see FIG. 1) that sprays a spray coolant onto the slab 3 and the support roll 2 in order to cool the support roll 2 for conveying the slab in continuous casting,
The injection port 4 for spraying the atomized coolant is connected to the slab 3.
It is formed in the shape of a wide slit extending in the width direction of the slab 3, and three strips are arranged parallel to each other in the conveying direction of the slab 3.

[0014] The injection port 4 at the center in the direction of conveyance of the slab is arranged so that the sprayed coolant is perpendicular to the slab 3 and uniform in its width direction, as shown in FIGS. 1(B) and (C). It is designed to be sprayed in a spread that provides cooling.

Further, the sprayed coolant is emitted from the front and rear injection ports 4' in the slab conveyance direction with the central injection port 4 sandwiched between them.
As shown in FIGS. 1B and 1C, it is formed so that it can be sprayed onto the support roll 2 in such a manner as to uniformly cool it in the axial direction thereof.

As shown in FIG. 2, the roll cooling nozzle 1 in this embodiment includes a base 5 for mixing water and air;
It is attached to this base 5, and each injection port 4, 4'
, 4' are formed in the injection part 6.

In order to actually cool the supporting roll 2 with the roll cooling nozzle 1 having such a configuration, the roll cooling nozzle 1 of the present invention was adopted in a continuous casting machine of 8 to 10 seg. 4000～
The support roll, which was unusable at 5000ch due to bending and wear, can now be used at 7000 to 8000ch.

[0018]

[Effects of the Invention] As described above, according to the roll cooling nozzle of the present invention, there is no need to increase the number of nozzles for cooling, so there is no need to change the conventional nozzle piping, and the number of maintenance steps remains the same. Therefore, external cooling of the nozzle, which is a measure to extend the life of the support roll used for conveying slabs, can be carried out at low cost.

Each injection port of the roll cooling nozzle has a width that is perpendicular to the slab to provide uniform cooling in its width direction, and a width that provides uniform cooling to the support roll in its axial direction. It is designed to be sprayed with atomized coolant. Therefore, the slab and the support rolls for conveying the slab can be efficiently cooled with the sprayed coolant.

[Brief explanation of the drawing]

[Fig. 1] (A) is a bottom view of the nozzle showing the injection port in the roll cooling nozzle of the present invention, and (B) is a schematic diagram showing the spray state of coolant sprayed onto a slab by the roll cooling nozzle of the present invention. In the front view, (C) is a schematic plan view showing the state in which the sprayed coolant is sprayed onto the slab by the roll cooling nozzle of the present invention.

FIG. 2 is a side view of the roll cooling nozzle of the invention.

FIG. 3 is a distribution characteristic diagram showing the water amount distribution characteristic in the slab width direction of the roll cooling nozzle of the present invention.

FIG. 4 is a distribution characteristic diagram showing the water amount distribution characteristic in the longitudinal direction of the slab of the roll cooling nozzle of the present invention.

[Explanation of symbols]

1... Roll cooling nozzle, 2... Support roll, 3... Slab, 4
, 4'... Injection port, 5... Base, 6... Injection part.

Claims (1)

[Claims] 1. A roll cooling nozzle that sprays a coolant spray onto the slab and the support roll in order to cool the support roll for conveying the slab in continuous casting, the roll cooling nozzle having an injection port for spraying the coolant. is formed in the shape of a wide slit extending in the width direction of the slab, and is provided with three strips parallel to the conveyance direction of the slab,
The injection port at the center in the slab conveying direction is formed so that the spray coolant is sprayed perpendicularly to the slab in a spread that provides uniform cooling in the width direction of the slab. The front and rear injection ports in the conveying direction with the injection ports sandwiched therebetween are formed so that the atomized coolant is sprayed onto the support roll in such a manner as to uniformly cool the support roll in its axial direction. Features: Roll cooling nozzle for continuous casting.