JPH0649208B2 - Hot steel plate cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention, when cooling a hot steel plate traveling on a hot run table, removes water and interference flow floating on the steel plate to ensure a uniform cooling effect. The present invention relates to a cooling device for doing so.

<Prior art and its problems> When a hot steel plate traveling on a hot run table is cooled by a cooling device such as a slit laminar or a pipe laminar, “water floating on the steel plate” or “cooling water flowing down from a cooling water nozzle” It has been pointed out that "interfering flow caused by collision" has a problem in uniform cooling and sometimes impairs the cooling capacity. Therefore, in terms of cooling efficiency and the like, it is important to remove the cooling water quickly after it has dropped onto the hot steel plate and is in contact with it before it becomes floating water or an interference flow.

For this reason, there has been attempted a method of removing floating water and interference flow on the hot steel plate by injecting high-pressure water from a high-pressure water nozzle to drain water.

However, if the above measures were taken, the following new problems would occur. That is, when a single high-pressure water nozzle is used to implement the draining means, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Application Laid-Open No. 0-149731 and Japanese Patent Application Laid-Open No. 61-231125, the high-pressure water nozzle collides with the high-pressure water jetted so as to sufficiently drain water over the entire width direction of the plate. The area is designed and arranged so as to be a "long range in the plate width direction that extends to the vicinity of the edge portion of the maximum width steel plate to be applied". For this reason, when it becomes necessary to cool a narrow hot steel plate by changing the plate width, the high-pressure water flow directly collides with the steel plate edge, which results in promoting local supercooling of the steel plate edge portion. Become. In other words, in the draining using the single high-pressure water nozzle, there was a problem that it was extremely difficult to control the cooling of the steel plate edge portion.

Therefore, in order to solve the above problem, as shown in FIG. 2, high-pressure water nozzles 2 are arranged on both sides of the hot run table 1 so as to face each other. A means has been proposed in which high-pressure water is jetted from the widthwise central portion of the hot-rolled steel plate 4 "to the outer end to drain the hot water (Shokai 57-106752).

However, this "draining method in which high-pressure water is jetted oppositely from the central part of the hot steel plate to the outer edge from the high-pressure water nozzles that are arranged facing each other on both sides of the hot run table" is certainly an "interference flow" or "floating water". Although it was possible to obtain a comparatively good effect in draining water, it is shown in Fig. 3 (a) when the cooling conditions (steel plate running speed, amount of cooling water, etc.) are still changed. "Stagnation" of the flow near the collision of the pressure water from the water nozzles 2, 2 with the surface of the hot steel plate 4
However, there is still a problem that the cooling capacity is hindered by these as well, because the interference flow is partially generated. In addition, since the injected pressure water flows along with the cooling water in a large amount toward both edge portions, there is a problem that the edge portions of the steel sheet are likely to be overcooled. Even if the ejection angles of the high-pressure water nozzles 2, 2 are set as shown in, for example, FIG. 3 (b), the cooling conditions cannot always be the same in the actual work. It was also confirmed that was inevitable. In addition,
Reference numeral 5 in the drawing indicates a cooling water nozzle (slit laminar, pipe laminar, etc.), arrows indicate the direction of the cooling water flow and the direction of high-pressure water, and a meshed portion indicates a collision portion of high-pressure water.

Therefore, the object of the present invention is to quickly and effectively remove the cooling water and the interference flow of the cooling water floating on the steel sheet after contributing to the cooling of the hot steel sheet, thereby improving the cooling ability. ,
Moreover, the present invention is intended to provide a means for cooling a hot steel sheet, which not only achieves uniform cooling in the width direction of the steel sheet but also can appropriately respond to changes in cooling conditions.

<Means for Solving the Problems> The inventors of the present invention conducted research from various viewpoints while repeating numerous experiments in order to achieve the above-mentioned object, and as a result, “on a traveling steel plate with a single high-pressure water nozzle”. The efficiency of removing floating water and interference flow and the uniform cooling property of the steel plate, which is also affected by these, are superior or inferior depending on the injection angle of the high-pressure water with respect to the direction of travel of the steel plate and the high-pressure water collision site on the steel plate surface. Therefore, it is important to adjust the collision area of the high-pressure water so that it does not hit the edge of the steel sheet. It is necessary to be able to adjust the angle of the high-pressure water nozzle according to changes in the cooling conditions in order to improve the above. "

The present invention has been made on the basis of the above findings and the like. “As shown in FIG. 1, a cooling water nozzle 5 for dropping cooling water onto the hot steel plate 4 surface running on a hot run table is provided. In a cooling device for a hot steel plate, which comprises cooling water floating on a steel plate surface and high-pressure water nozzles 2 for discharging and removing an interference flow of the cooling water, arranged on both sides of the hot run table. The angle of the high-pressure water nozzles 2, 2 for removing the water interference flow can be adjusted within a range from the direction perpendicular to the steel plate traveling direction to the direction of ± 45 °, and the jetted high-pressure water flow does not hit the edge of the hot steel plate directly. The feature is that it is installed at an angle.

Hereinafter, the present invention will be described in more detail with its operation based on the drawings.

<Operation> FIG. 4 is a schematic view schematically showing an example of the cooling device according to the present invention, in which FIG. 4 (a) is a front view thereof, and FIG. 4 (b) and FIG. FIG. (C) shows a plan view when the angles of the high-pressure water nozzles 2, 2 with respect to the traveling direction of the steel plate are adjusted to be different from each other.

In the cooling device shown in FIG. 4, a hot steel plate 4 rolled into a predetermined size by, for example, a rolling mill (not shown)
When is transported onto the hot run table (roll) 1, cooling is started in accordance with a predetermined cooling pattern by a large number of cooling nozzles (slit laminar or pipe laminar) 5, 5 arranged in the traveling direction as in the conventional case. It

However, the cooling water dropped from the cooling nozzles 5, 5 is
Immediately below the nozzle contributes to the cooling of the hot steel plate 4,
After that, the cooling water floating on the steel plate acts as an interference flow between the cooling nozzles 5, 5 or forms a vapor film to hinder uniform cooling.

However, in the cooling device shown in FIG. 4, “high-pressure water nozzles 2, 2 set at an angle at which the jetted high-pressure water stream does not hit the edge of the hot steel plate directly” are installed on both sides of the hot run table 1. Since the interference flow and the vapor film are quickly removed (drained) by the jet water flow from the water nozzle, nonuniform cooling due to these is prevented. The high-pressure water jets injected from the high-pressure water nozzles 2, 2 do not directly hit the edge of the steel plate as shown in FIGS. 4 (b) and 4 (c), so the steel plate edge portion Does not lead to overcooling. Moreover, since the direct hit portion of the high-pressure water flow does not hit the steel plate edge, the colliding pressure water diffuses to a certain extent on the steel plate and flows out together with the cooling water of a relatively wide part. Therefore, the pressure water accompanied by the cooling water does not deviate from the edge portion in a short-circuited manner. Therefore,
The supercooling of the edge portion due to the mixed flow of the cooling water and the pressure water flowing out in a large amount in a biased manner is also prevented.

Moreover, since the high-pressure water nozzles 2, 2 are of a swinging type in which the angle can be adjusted in the range from the direction perpendicular to the steel plate traveling direction to the ± 45 ° direction, cooling conditions are, for example, "low line". Fig. 4 (b) for "speed / small cooling water"
As shown in, if the jet direction of the high-pressure water nozzles 2, 2 is set at a right angle to the steel plate traveling direction or an angle direction close thereto, smooth removal of the cooling water that has finished the role of cooling can be performed. On the other hand, when the cooling condition changes to "high line speed / multi-cooling water amount", the injection direction of the high-pressure water nozzles 2,2 is "± 30 ° from the direction perpendicular to the steel plate traveling direction as shown in Fig. 4 (c). Furthermore ± 4
By changing / adjusting to an angle of about 5 °, the cooling water that has finished its cooling function can be removed more quickly. Thus, the angle of the high-pressure water nozzle can be adjusted according to the cooling conditions. When performed, no matter how the cooling conditions change, "elimination of" stagnation "that tends to occur in the central part of the steel plate due to floating water or interference flow" and "pressure water flow accompanied by cooling water is biased and both edges of the steel plate `` Controlling / suppressing the phenomenon that a large amount of water flows out from the pipe is effectively performed. It is possible to equalize the amount of passing water at any position in the hot plate, and it is possible to efficiently cool the hot steel plate while suppressing uneven cooling in the plate width direction.

Here, the reason why the angle adjustment range of the high-pressure water nozzle is limited to “from the direction perpendicular to the steel plate traveling direction to the ± 45 ° direction” is as follows.

That is, the preferable ejection angle of the high-pressure water nozzle with respect to the steel plate traveling direction also depends on the interval between the cooling water nozzles (slit laminar, pipe laminar, etc.). That is, when the arrangement interval of the cooling water nozzles becomes long, the preferable ejection angle (absolute value) when the direction perpendicular to the steel plate traveling direction is 0 ° becomes large, but when this angle goes out of the range of 0 to ± 45 °. A dead zone (a region that is not cooled by the cooling water) generated between the high-pressure water streams injected oppositely becomes wide, and uniform cooling is hindered. For this reason, the angle adjustment range of the high-pressure water nozzle is ± 45 ° from the direction perpendicular to the steel plate traveling direction.
However, it is preferably 0 to ± 30 ° with respect to the traveling direction of the steel sheet.

It is suitable that the water jet pressure from the high-pressure water nozzle is about 5 to 12 kg / cm ² .

Then, the cooled steel plate is usually wound as it is by a down coiler.

By the way, FIG. 5 shows a case where the hot steel plate is cooled while the angle of the high-pressure water nozzle is adjusted by the cooling device according to the present invention, and a conventional cooling device having a fixed high-pressure water nozzle whose angle cannot be adjusted (see FIG. It is the graph which compared the temperature distribution of the board width direction at the time of cooling a hot steel plate by the apparatus shown in FIG.

The result of this investigation is 850 ℃ after hot rolling ordinary steel.
It was obtained under the condition that it was finished with, and immediately after that, it was continuously cooled by the above cooling device and then wound at 480 ° C. Fig. 5 (a) shows the result by the conventional device, and Fig. 5
(b) shows the results obtained by the device of the present invention.

From the results shown in FIG. 5 above, it can be confirmed that the cooling uniformity in the plate width direction is remarkably improved by the apparatus of the present invention.

<Summary of Effects> As described above, according to the present invention, it is possible to perform good draining of the steel plate surface according to the cooling conditions of the hot steel plate, and the increase of the draining efficiency results in the cooling ability and the plate width. Industrially useful effects such as significantly improved cooling uniformity in the direction are provided.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a “cooling device for hot steel sheet” according to the present invention. FIG. 2 is an explanatory view of a conventional "cooling apparatus for hot steel plate". FIG. 3 is an explanatory view of the water draining condition in the conventional “cooling device for hot steel plate”, and FIGS. 3 (a) and 3 (b) show examples in which the angles of the high pressure water nozzles are different. Shows. FIG. 4 is a schematic view schematically showing an example of the cooling device according to the present invention, FIG. 4 (a) is a front view thereof, and FIG. 4 (b) and FIG. 4 ( c) is a plan view when the angles of the high-pressure water nozzles 2, 2 with respect to the traveling direction of the steel plate are adjusted to different states. FIG. 5 shows a case where the hot steel plate is cooled by the conventional cooling device [FIG. 5 (a)] and a case where the hot steel plate is cooled while the angle of the high-pressure water nozzle is adjusted by the cooling device according to the present invention [ FIG. 5 (b)] is a graph comparing the temperature distribution in the plate width direction. In the drawings, 1 ... Hot run table, 2 ... High-pressure water nozzle, 3 ... Cooling water, 4 ... Hot steel plate, 5 ... Cooling water nozzle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Haraguchi 4-53-3 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries Co., Ltd. (56) Reference JP-A-59-202113 (JP, A) Kai-sho 61-133209 (JP, A)

Claims (1)

[Claims] 1. A cooling water nozzle for dropping cooling water on a hot steel plate surface traveling on a hot run table,
In a cooling device for a hot steel plate comprising cooling water floating on a steel plate surface and high-pressure water nozzles for discharging and removing the interference flow of the cooling water, the floating cooling water and the cooling water interference flow are The high-pressure water nozzle for removal can be angle-adjusted within a range from the direction perpendicular to the steel plate traveling direction to its ± 45 ° direction, and the jetted high-pressure water flow is installed at an angle that does not hit the edge of the hot steel plate directly. Characteristic,
Cooling system for hot steel sheets.