JPH08215733A - Cooling equipment of steel plate - Google Patents

Abstract

PURPOSE: To prevent the defective shape or the variance in the material by providing two rows of nozzles to make injections from the middle of the steel plate in the direction of the end part of the plate width, and arranging the injecting direction so as to be alternately opposite to each other along the advancing direction of the steel plate to unify the cooling. CONSTITUTION: A plurality of headers 3a, 3b provided with cooling nozzles 4a, 4b are provided between rolls 2a, 2b rotated by a driving equipment in two rows along the longitudinal direction above the steel plate 1 to be advanced in the direction A. The cooling liquid 9 is injected from the cooling nozzle 4a, 4b from the center of the steel plate 1 to the direction of the end part of the plate width as indicated by the arrow B. The nozzle 4a, 4b are installed with the prescribed intervals so that the jet of the cooling liquid 9 may not to be interfered by each other, and the cooling liquid smoothly flows without generating the unstable interfering flow through the collision with the steel plate 1. The cooling control capable of obtaining the desired cooling characteristics in the cooling area is realized, the interfering flow generated on the steel plate 1 and the supercooling can be prevented, and the product of stable quality can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for controlled cooling of hot-rolled high temperature steel sheet.

[0002]

2. Description of the Related Art In general, when a hot rolled hot steel sheet is cooled by a nozzle such as a slit laminar or a pipe laminar, a nozzle adjacent to the steel sheet causes a cooling liquid to flow down and the steel sheet is sprayed from the nozzle. The generated cooling water collides with the high-temperature steel plate and then divides into four directions on the surface of the steel plate to form a flowing water region. When such cooling is performed, the collision area where the cooling water collides with the steel sheet has a larger cooling capacity than the flowing water area formed after the collision and locally supercools. It causes variation.

On the other hand, after the cooling water sprayed from the nozzle collides with the steel plate, the flowing water flows on the steel plate and collides with the flowing water formed from other nozzles to form an interference flow. The behavior of this interference flow is generally unstable, and a part of this interference flow reaches the collision area of another nozzle, which reduces the cooling capacity and causes variations in cooling of the steel sheet.

As a measure for solving such a problem, Japanese Patent Laid-Open Publication No. 54-57413 discloses a method in which a high temperature steel plate 1 during transportation as shown in FIG. And a cooling nozzle 7 installed to flow the cooling liquid 9 in the width direction of the high temperature steel plate 1 is disclosed.
Japanese Patent No. 165216 discloses a high temperature steel plate 1 as shown in FIG.
A device is proposed in which the cooling liquid 9 is made to flow down by the nozzle 8 in which the longitudinal center of the header substantially coincides with the central part of the steel plate in the steel plate traveling direction A from approximately the upper center of the plate, and the cooling liquid 9 is dropped from both ends in the plate width direction. Has been done.

[0005]

However, in the device disclosed in Japanese Patent Laid-Open No. 54-57413, since the cooling liquid flows only in one direction, it occurs when cooling is performed from above the steel plate with a cooling device such as a pipe laminar. Although the interference flow on the steel plate and the supercooling due to the collision of the cooling liquid do not occur, as shown in FIG. 7, the tip of the cooling nozzle 7 is made to coincide with one plate width end of the steel plate and the other plate is The cooling liquid 9 is caused to flow toward the width end portion, and the tip end of the nozzle 7 described above is made to coincide with the end portion of the steel plate 1 due to variations in the width of the steel sheet, variations in the passage position of the steel sheet in the width direction, and the like. difficult. Therefore, since a portion where the cooling liquid does not flow occurs at the plate width end, uniform cooling in the width direction is impossible unless a device for moving the nozzle position or a guide device for fixing the plate passing position is used. .

On the other hand, Japanese Unexamined Patent Publication No. 55-16521 shown in FIG.
In the device shown in Japanese Patent Publication No. 6, the cooling liquid 9 ejected from the cooling nozzle 8 installed substantially above the center of the steel plate collides with the steel plate 1 and then flows in the plate width direction while maintaining the collision speed substantially in a straightened state. Since it falls downward from both ends of the plate width, there is no portion where the cooling liquid does not flow in the plate width direction, which is a problem in the device proposed in Japanese Patent Laid-Open No. 54-57413.
However, since the cooling liquid 9 continuously collides with the central portion of the steel plate, it becomes supercooled as compared with the flowing water portion in the plate width direction, and uniform cooling cannot be achieved.

The present invention solves the above-mentioned conventional problems and reduces the cooling variation due to the interference flow formed on the steel plate when the cooling device is used to inject the cooling liquid from a plurality of nozzles from above the steel plate. It is an object of the present invention to provide a cooling device that prevents a collision portion immediately below a nozzle from being overcooled and uniformly and efficiently cools a steel sheet.

[0008]

That is, in the cooling device of the present invention, jetting is performed from above the hot steel plate being conveyed to the central part in the plate width direction of the steel plate, and from the central part in the plate width direction of the steel plate to the end part of the plate width. A plurality of nozzles having different directions are provided in two rows, and the nozzle ejection directions of the two rows are arranged so as to alternately face each other along the traveling direction of the steel sheet.

[0009]

An embodiment of the present invention will be described in detail below with reference to the drawings. 1 is a plan view schematically showing a main part of a first example of a cooling device according to the present invention, and FIG. 2 is a transverse sectional view taken along the line YY schematically showing the cooling liquid jetting part of FIG. Is. In the cooling device shown in FIG. 1, the high-temperature steel plate 1 is rolled into a predetermined size by, for example, a rolling mill (not shown), and then conveyed to the cooling device by a conveying device (not shown). In the cooling device of FIG. 1, rotating rolls 2 a and 2 b for sandwiching the steel plate 1 are arranged on the upper surface and the lower surface of the steel plate 1 at predetermined intervals in the longitudinal direction of the steel plate 1 and are in contact with the steel plate 1. These rolls 2a and 2b are rotated by a driving device (not shown), and the steel plate 1 moves in the direction of arrow A. Between the rolls 2a and 2b, headers 3a and 3b having one or a plurality of cooling nozzles 4a and 4b are arranged above the high-temperature steel plate 1 in two rows in the longitudinal direction of the steel sheet 1, and in each row. Said headers 3a and 3b are 1
One or more are installed.

As shown in FIG. 2, the nozzles 4a and 4b installed on the headers 3a and 3b are arranged in the central portion of the high-temperature steel plate 1 in the width direction, and in two rows at predetermined intervals from the central portion of the steel plate in the width direction. The cooling nozzles 4a, 4
As shown by the arrow B from b, the cooling liquid 9 is sprayed from the central portion of the steel plate 1 toward the plate width end portion. The nozzles 4a and 4b are alternately installed at predetermined intervals so that the cooling liquids 9 that flow in opposite directions do not interfere with each other in the central portion of the nozzles.

The incident angle C of the cooling liquid 9 is less than 60 °, preferably 0 ° to 45 ° with respect to the horizontal direction of the steel plate 1 so as not to form a collision area on the steel plate 1 as shown in FIG. Thus, the distance between the nozzle and the steel plate is set so that the cooling liquid does not form a collision part and flows along the steel plate 1 without splashing from the surface of the steel plate.

In this way, the plurality of nozzles 4a and 4b are installed in two rows at the central portion of the steel plate 1 in the plate width direction, and the cooling liquid 9 is supplied to the steel plate 1.
By flowing from the center of the steel plate to the end of the plate width along
The unstable interfering flow formed on the steel plate that causes the cooling unevenness of the steel plate, which is generated in the cooling device that injects the cooling liquid toward the steel plate from above the steel plate to cool, is eliminated. Further, since the cooling liquid 9 is not jetted from above the steel plate perpendicularly to the horizontal direction of the steel plate, but the incident angle of the cooling liquid 9 is set along the steel plate, it is possible to prevent overcooling due to collision of the cooling liquid.

On the other hand, since the cooling liquid 9 is made to flow from the central portion in the width direction of the steel plate to the end portion of the plate width, even if the width of the steel plate changes or the position of the steel sheet passing in the width direction changes, a guide device for the steel plate, etc. It is possible to flow the cooling liquid in the entire width direction of the plate without the position control device, and there is no portion where the cooling liquid does not flow.

If a plurality of cooling portions shown in FIG. 1 are provided in the traveling direction of the steel sheet and the type, injection speed, amount, pressure, temperature, etc. of the cooling liquid in each zone are changed, desired cooling characteristics can be obtained in each cooling zone. It is possible to obtain controlled cooling. Since the cooling capacity changes depending on the cooling water temperature, cooling water flow rate, and flow rate, it is determined in advance by preliminary experiments, calculations, and the like.

FIG. 3 is a plan view schematically showing the main part of the second example of the present invention. This embodiment is an example in which the rolls 2a and 2b are not installed in the embodiment shown in FIG. In this embodiment, a water draining facility 6 such as a spray is installed to partition the cooling portion. Therefore, this embodiment is suitable for uniformly cooling the steel sheet when the steel sheet conveying speed is high. If a plurality of cooling parts shown in FIG. 3 are provided in the traveling direction, desired cooling characteristics can be obtained in each cooling zone as in the apparatus example shown in FIG. 1, and control cooling becomes possible. In this case, the cooling part may be continuously installed in the steel sheet traveling direction or may be installed at a predetermined interval. A plurality of drainers 6 may be installed at predetermined intervals in the cooling section so that the injected cooling liquid does not interfere with each other, or may be installed at the end of the cooling section.

FIG. 4 is a cross-sectional view schematically showing the cooling liquid jetting portion of the third example of the present invention. In this embodiment, one header 3 installed above the central portion of the steel plate in the plate width direction is provided with a plurality of nozzles 4 having two rows and a jet direction in the end direction of the plate width.
a and 4b are provided, and the nozzle ejection directions of the two rows are alternately arranged along the traveling direction of the steel sheet.
Note that the device example is not limited to this as long as the device has the above structure.

When the position of the cooling liquid 9 ejected from the nozzles 4a and 4b on the steel plate is largely displaced from the central portion of the steel plate 1, the positions of the headers 3a and 3b can be moved in the plate width direction of the steel plate. It may be a structure. The nozzles and headers may be arranged in the central portion of the steel plate in the plate width direction alternately facing each other in the plate width direction, and the nozzles and headers having the above-described structure may have different shapes. Or the number of nozzles provided in the header,
Any shape may be used. In addition, a device for changing the elevating device for the headers 3, 3a, 3b, the spray angle of the cooling nozzles 4a, 4b facing each other, the distance from the center of the steel plate in the width direction of the steel plate, and the distance in the traveling direction of the steel plate may be provided. good.

[0018]

EXAMPLE FIG. 5 shows a thickness of 10 mm, a width of 1000 mm and a length of 20.
When a steel plate of 00 mm is cooled by the apparatus of the present invention shown in FIG. 1, the average cooling rate until the steel plate falls from 800 ° C. to 500 ° C. is shown in the plate width direction, and FIG. 6 shows a comparative example. Until the steel plate drops from 800 ° C. to 500 ° C. when the steel plate is cooled by supplying cooling water from above the center part of the plate width by a slit nozzle installed so as to be parallel to the steel plate longitudinal direction from above the center part of the steel plate. The average cooling rate is shown in the plate width direction.

The results of FIG. 5 are obtained when the cooling nozzle is set to 0 ° for cooling the steel sheet, but no cooling liquid flows on the steel sheet and no interference flow on the steel sheet occurs. Since there is no overcooling due to the collision of the cooling liquid, the cooling rate variation is within 2 ° C / s in the plate width direction. On the other hand, FIG.
In the case, the central portion of the steel sheet width direction, which is directly under the nozzle, is overcooled due to the collision of cooling, resulting in a cooling variation of 5 ° C./s or more compared to other portions.

[0020]

According to the apparatus of the present invention, the interference flow of the cooling liquid generated on the upper surface of the steel sheet, which causes the uneven cooling,
It is possible to prevent overcooling due to collision of cooling liquid and significantly improve cooling uniformity, which can prevent shape defects due to uneven cooling and variation in product materials, and can provide products with stable quality, which is an industrially beneficial effect. Is brought about.

[Brief description of drawings]

FIG. 1 is a plan view showing a main part of a first device example of the present invention.

FIG. 2 is a view showing a cooling liquid jetting portion of a first device example of the present invention.
YY line sectional drawing.

FIG. 3 is a plan view showing a main part of a second device example of the present invention.

FIG. 4 is a cross-sectional view showing a cooling liquid jetting portion of a third device example of the present invention.

FIG. 5 is a graph showing a cooling rate of a steel sheet according to the present invention.

FIG. 6 is a graph showing a cooling rate of a steel sheet according to a comparative example.

FIG. 7 is an explanatory diagram of a cooling device in which a single cooling nozzle is installed parallel to the traveling direction of the steel sheet and a cooling liquid is caused to flow in the plate width direction.

FIG. 8 is an explanatory view of a cooling device using a nozzle in which a longitudinal direction of a header is substantially aligned with a steel plate traveling direction from a substantially upper center of the steel plate.

[Explanation of symbols]

 1 Steel Plate 2a Roll 2b Roll 2c Pressing Roll 3 Header 3a Header 3b Header 4a Cooling Nozzle 4b Cooling Nozzle 5 Cooling Liquid Supply Pipe 6 Drainer 7 Cooling Nozzle 8 Cooling Nozzle 9 Cooling Liquid A Steel Plate Traveling Direction B Cooling Liquid Jetting Direction C Cooling Liquid Incident angle of

Claims (1)

[Claims] 1. A plurality of nozzles having a jetting direction from the center of the steel plate in the plate width direction to the end of the plate width in the plate width direction are provided in two rows from above the high temperature steel plate being conveyed. Two
A cooling apparatus for a steel sheet, characterized in that the nozzle ejection directions of the rows are arranged so as to alternately face each other along the traveling direction of the steel sheet.