JPH10277626A - Device for cooling steel strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate ununiformity of cooling water relating to the width direction of a hot rolled steel strip which is coiled at low temp. and bad appearance in the edge part sides in the width direction of the steel strip due to the ununiformity of the cooling water by jetting or stopping the cooling water by slightly moving an interrupting plate having through holes for passing through the cooling water which is jetted like a column from nozzle. SOLUTION: This steel strip cooling device 50 is provided with the nozzles 21a-21f for jetting the flows 23a-23f of the cooling water on the surface of the steel strip 11, interrupting plate 31 which is arranged so as to be freely changed to the interrupting position B where the plate is collided against the flows 23a-23f of the cooling water and the un-interrupting position A where the plate is not collided and also has the through holes 32a-32f through which the flows 23a-23f for the cooling water are passes when the interrupting plate is in the un-interrupting position A, drain through 41 receiving the cooling water which is flowed down after colliding against the interrupting plate 31 and discharging it outside the system and gas jetting nozzles 51a, 51f, which are provided on the upper surface of the interrupting plate 31, for making the flows 23a, 23f of the cooling water flow down into the drain through 41 by jetting gas against the currents 23a, 23f of the cooling both end part sides of the steel strip when the interrupting plate 31 in the un-interrupting position A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a steel strip cooling apparatus, and more particularly to a steel strip cooling apparatus for cooling a steel strip after hot rolling.

[0002]

2. Description of the Related Art In recent years, in a process for producing a steel sheet such as a hot-rolled steel sheet, controlled cooling for obtaining a high-strength and high-toughness steel sheet by performing on-line accelerated cooling of a controlled-rolled steel strip has been widely performed.

FIG. 8 is a schematic explanatory view showing a controlled cooling process of a hot-rolled steel sheet. The steel strip 2 that has been finish-rolled by the finish rolling mill 1 of the hot rolling apparatus has an upper surface cooling device 3 that cools the upper surface of the steel strip 2 and a lower surface cooling device 4 that cools the lower surface, and the upper surface side and the lower surface side thereof are online. It is controlled and cooled from the lower surface side and wound up by the coiler 5.

The upper surface cooling device 3 for cooling the upper surface of the steel strip 2 generally employs a pipe laminar method. FIG.
9 (a) is a vertical cross-sectional view of the steel strip 2 at the center in the width direction, and FIG. 9 (b) is a sectional view taken along the line A-A in FIG. 9 (a). It is an arrow A view.

The upper surface cooling device 3 has three headers 6 arranged side by side at predetermined intervals in the transport direction above the steel strip 2 transported in the direction of the arrow in FIG. 9 (a).
As shown in FIG. 9 (b), a large number of nozzles 7 for discharging cooling water are attached at predetermined intervals in the longitudinal direction (the width direction of the steel strip 2) of these headers 6, 6, 6. Each nozzle
Numeral 7 is, for example, curved in a substantially arc shape from the uppermost portion of the header 6 and extends downward, and has an inverted U-shaped outer shape. Cooling water is supplied to the inside of the header 6 from one end thereof,
The supplied cooling water is injected from each nozzle 7 as a plurality of columnar laminar flows 8 onto the upper surface of the steel strip 2. Thus, the high-temperature steel strip 2 is uniformly accelerated and cooled to a desired winding temperature in the width direction.

[0006] Higher strength and higher toughness of the steel strip, which has been conventionally realized by optimizing the amount of added elements, can be realized by combining this controlled cooling and controlled rolling.
Not only energy savings and cost savings, but also significant improvements in the mechanical properties of steel strips.

By the way, in the top surface cooling device 3 of the pipe laminar type shown in FIG.
It is extremely important that the cooling water is simultaneously jetted from the nozzles 7 and that the jetting of the cooling water from each nozzle 7 ends at the same time when cooling is completed. If the cooling water jetting timing and the stop timing from the nozzles 7 arranged side by side in the width direction of the steel strip 2 do not match, the cooling becomes uneven in the width direction of the steel strip 2, and in the worst case, This is because appearance defects such as ear wave deformation occur at both end portions in the width direction.

[0008] Therefore, conventionally, in the top surface cooling device of the pipe laminar type, it is required to match the timing of jetting and stopping the cooling water jetted from the nozzle, that is, to improve the responsiveness regarding the jetting of the cooling water. Various proposals have been made.

For example, Japanese Patent Publication No. 45-29891 discloses a shut-off plate capable of shutting off a cooling water flow between the tip of a nozzle and a steel strip, and receives a cooling water that collides with the shut-off plate and flows down. A cooling device is disclosed in which a water receiver connected to a header is arranged to improve responsiveness at the time of cooling water injection / stop.

Japanese Patent Application Laid-Open No. Sho 62-179807 discloses that the widthwise end of the steel strip from which the injected cooling water is finally discharged is more likely to be supercooled than the center in the widthwise direction. ,
As a countermeasure against the above-mentioned appearance defect, a cooling water cut-off device is installed between the tip of the nozzle and the steel strip to form a cooling water cut-off area and a non-cut-off area by exhibiting irregularities along the width direction of the steel strip. A cooling device is described.

[0011]

However, even with these proposals, the cooling in the width direction of the hot-rolled steel strip, particularly the hot-rolled steel strip of low-temperature winding, is not uniform, and the width direction of the steel strip caused by this is not uniform. It is not possible to eliminate poor appearance at the end.

That is, the cooling device described in Japanese Patent Publication No. 45-29891 shuts off the cooling water flow by rotating the cutoff plate by about 90 degrees, so that it exhibits the responsiveness currently required. It is not possible. Further, in the cooling device described in this publication, no countermeasures are taken against supercooling at the widthwise end of the steel strip, and the above-described appearance defect cannot be eliminated.

Although the cooling device described in Japanese Patent Application Laid-Open No. Sho 62-179807 certainly enables uniform cooling of the steel strip, extremely large cooling water shut-off devices are densely packed. It must be arranged between the arranged nozzles, and again, the feasibility is low.

As described above, it is difficult to apply the conventional steel strip cooling apparatus to existing equipment, and the steel strip is uniformly cooled in the width direction to a predetermined temperature, and the appearance of the steel strip at the end in the width direction is poor. Could not be eliminated. Here, an object of the present invention is to provide a steel strip cooling device that can solve such a conventional problem.

[0015]

Means for Solving the Problems The present inventors have eagerly studied means for improving the responsiveness and uniformity of cooling water jetting and stopping from a number of nozzles connected to a cooling water supply header. As a result of the examination, it was found that the cooling water was jetted and stopped by finely moving the shut-off plate having a through hole through which the cooling water jetted from the nozzle passes. In the cooling device that jets out in a columnar shape, a cooling water cutoff mechanism that changes a part of the cooling water flow is arranged, and the steel strip can be controlled more independently by controlling the amount of cooling water injected to the ear wave generator. The present invention was also found to be able to cool to a desired temperature with high accuracy and uniformity in the width direction, thereby solving the above-mentioned problem, and completed the present invention.

Here, the gist of the present invention is a cooling device for a steel strip to be conveyed, which is juxtaposed in the width direction of the steel strip and ejects a plurality of cooling water flows toward the surface of the steel strip. A plurality of nozzles, and a blocking member arbitrarily arranged to be able to be changed to a blocking position for blocking the cooling water flow to the surface of the steel strip by colliding with the plurality of cooling water flows and a non-blocking position not colliding with the plurality of cooling water flows, A drainage mechanism disposed below the blocking member located at the blocking position and receiving cooling water that collides with the blocking member and flows down and discharges the cooling water to the outside of the system, and cools when the blocking member is at the non-blocking position. It is characterized by having a plurality of through holes through which a water flow passes.

Further, from another viewpoint, the present invention relates to a cooling device for a steel strip to be conveyed, wherein the cooling device is arranged side by side in the width direction of the steel strip and ejects a plurality of cooling water flows toward the surface of the steel strip. A plurality of nozzles, and a blocking member arbitrarily arranged to be able to be changed to a blocking position for blocking the cooling water flow to the surface of the steel strip by colliding with the plurality of cooling water flows and a non-blocking position not colliding with the plurality of cooling water flows, A drainage mechanism disposed below the blocking member located at the blocking position and receiving the cooling water flowing down by colliding with the blocking member and discharging the cooling water to the outside of the system; and a cooling water flow when the blocking member is at the non-blocking position. A cooling water flow shut-off mechanism for flowing a cooling water flow directly affecting cooling of a portion of the steel strip where supercooling occurs to a drainage mechanism is provided.

In the above steel strip cooling apparatus according to the present invention,
It is desirable from the viewpoint of simplification of equipment that the cooling water flow cutoff mechanism is a gas injection device that injects gas into a cooling water flow that directly affects cooling of a portion where supercooling occurs.

In the steel strip cooling apparatus according to the present invention, the blocking member has a plurality of through holes through which the cooling water flows when the blocking member is at the non-blocking position, and guides the cooling water into which the gas is injected. It is desirable that the plate-shaped member be located at a position where the steel strip is caused to flow down to the drainage mechanism in order to uniformly cool the steel strip to a predetermined temperature in the width direction. In the steel strip cooling device according to the present invention, it is desirable that the cooling water flow blocking mechanism be provided on the collision surface of the blocking member with the cooling water flow in order to reduce the size.

According to the present invention, it is desirable for the downsizing of the equipment that the change of the blocking position and the non-blocking position of the blocking member is performed by a rotary motion about the vicinity of the end of the blocking member as the center of rotation. . Further, in these inventions,
It is desirable that the drainage mechanism is a drainage gutter installed over the steel strip in the width direction of the steel strip so as to reduce the size of the equipment.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of a main part of a steel strip cooling device 10 of the present embodiment, which is extracted and partially seen through.

The hot-rolled steel strip 11 which has been subjected to hot rolling to a predetermined thickness is conveyed on a hot run table in a direction indicated by a white arrow in the figure, and is provided with a coiler (not shown) installed in a downstream process. ) To take up the coil. The steel strip cooling device 10 of the present embodiment is installed above a hot-rolled steel strip 11 on a hot run table.

The steel strip cooling apparatus 10 of the present embodiment includes a combination of an inverted U-shaped nozzle group 20, a blocking member 30, and a drainage mechanism 40,
A plurality of sets are provided in the steel strip conveying direction, and two sets of these combinations and four sets of the inverted U-shaped nozzle group 20 are shown in the illustrated range. Since the elements of each combination are the same, the following description of the embodiment will be made by taking the example of the combination of the inverted U-shaped nozzle group 20, the blocking member 30, and the drainage mechanism 40, and the same for other combinations. Double letters (-1, -2, -3)
, Duplicate description will be omitted.

The inverted U-shaped nozzle group 20 is composed of six tubes which are curved upward in a substantially arc shape and are directed downward.
21a to 21f. Inverted U-shaped nozzles 21a to 21
f are arranged in a line in the width direction of the hot-rolled steel strip 11 at equal intervals, and each one end opening is directed to the surface of the hot-rolled steel strip 11 located below. The other end opening is connected to the pipe laminar header 22.

The pipe laminar header 22 is a cooling water supply for flowing cooling water therein. The pipe laminar header 22 is supported and supported by a stand (not shown) above the hot-rolled steel strip 11 and in the width direction. On the outer surface of the pipe laminar header 22, the other ends of the inverted U-shaped nozzles 21a to 21f are attached in a line at equal intervals in a communicating state. Accordingly, when cooling water is supplied to the inside of the pipe laminar header 22 with appropriate pressure, columnar laminar flows 23a to 23f, which are cooling water flows, are ejected downward from one end openings of the inverted U-shaped nozzles 21a to 21f. Is done.

In this embodiment, since the inverted U-shaped nozzle groups 21 and 21-1 are provided in the conveying direction of the hot-rolled steel strip 11 from one pipe laminar header 22, the number of pipe laminar headers to be installed is limited. Can be reduced. Therefore, even if a large number of inverted U-shaped nozzles are densely arranged, they can be easily installed.

The blocking member 30 is provided between the inverted U-shaped nozzle group 20 and the hot-rolled steel strip 11. The blocking member 30 includes a blocking plate 31 and a rotating shaft 33. The shielding plate 31 is a hot-rolled steel strip 11
It has a rectangular planar shape that can cover the entire surface in the width direction of the steel strip 11 and is installed over the hot-rolled steel strip 11 in the width direction. The blocking plate 31 has through holes through which the laminar flows 23a to 23f pass at the same pitch as the laminar flows 23a to 23f.
32a to 32f are formed.

These through-holes 32a to 32f form laminar flows 23a to 32f when the blocking plate 31 is in the non-blocking position A (in the case shown in FIG. 1 or FIG. 3) as described later with reference to FIG.
It is provided so as to penetrate through 23f and jet to the surface of the hot-rolled steel strip 11. Therefore, it is formed to be inclined at a predetermined angle with respect to the blocking plate 31.

The blocking plate 31 is fixed to the outer peripheral surface of the rotating shaft 33 by an appropriate means such as fastening. It is desirable to form a flat portion for attaching the blocking plate 31 on a part of the outer peripheral surface of the rotating shaft 33 for secure attachment. The rotating shaft 33 is a cylindrical body rotatable in both directions with respect to the center axis, and is supported over the hot-rolled steel strip 11 in the width direction.

FIG. 2 is an explanatory view showing a drive unit of the rotating shaft 33. As shown in the figure, both ends 33a, 33a of the rotating shaft 33 are provided.
Are supported by bearings 35, 35 supported by the mounts 34, 34. Connecting members 36, 36 are fixed to both ends 33a, 33a, and the ends of the air cylinders 38, 38 supported by the mounts 37, 37 are connected to the ends of the connecting members 36, 36 so as to extend and contract. Is done. Therefore, by operating the air cylinders 38, 38, the rotating shaft 33 rotates in both directions about the central axis. As described above, in the present embodiment, since the rotation shaft 33 is used to drive the blocking plate 31, the drive unit can be made as small as possible.

Since the blocking plate 31 in this embodiment is fixed to a rotating shaft 33 rotatable in both directions, it rotates about the central axis of the rotating shaft 33 so that the laminar flows 23a to 23a are rotated.
The relative positional relationship with 23f can be changed.
That is, the blocking plate 31 collides with the laminar flows 23a to 23f to block the arrival of the laminar flows 23a to 23f to the steel strip 11 (see FIG. 4 described later), and the laminar flows 23a to 23f.
f or the non-blocking position A (FIG. 1 or FIG.
See also).

Below the blocking plate 31 at the non-blocking position B,
A drainage mechanism 40 is provided which receives the cooling water flowing down by colliding with the blocking plate 31 and discharging the cooling water out of the system. In the present embodiment, as the drainage mechanism 40, a drainage gutter 41 installed over the hot-rolled steel strip 11 in the width direction of the steel strip and used. Since the drain gutter 41 has a small and simple structure, the installation space is small, and the drain gutter 41 can be sufficiently applied to an existing cooling device.

The steel strip cooling device 10 of the present embodiment is configured as described above. Next, the operation of the steel strip cooling device 10 will be described. FIG. 3 is an explanatory view showing a state where the steel strip is cooled in the state shown in FIG. 1, and FIG. 4 is an explanatory view showing a state where the steel strip is not cooled.

In FIG. 3, the rotation position of the rotating shaft 33 is adjusted so that the blocking plate 31 is located at the non-blocking position A where the laminar flows 23a to 23f pass through the through holes 32a to 32f.
In this state, the cooling water supplied to the pipe laminar header 22 is jetted downward as laminar flows 23a to 23f from the tip openings of the inverted U-shaped nozzles 21a to 21f. The jetted laminar flows 23a to 23f are supplied to the through holes 32a to 32
f, and further passes near the drain gutter 41, and collides with the surface of the hot-rolled steel strip 11. Thereby, the hot-rolled steel strip 11 is cooled.

Next, when cooling is completed, the rotating shaft 33 is rotated by a small angle in the direction shown by the arrow in FIG. 3 so that the laminar flows 23a to 23f cannot pass through the through holes 32a to 32f. . The state after this rotation is as shown in FIG. The laminar flows 23a to 23f collide with the edge 31a of the blocking plate 31 and flow down the surface of the blocking plate 31 from the end. The cooling water that flows down is drained by a drain gutter
Because it is received by 41, it does not reach the surface of the hot-rolled steel strip 11. To cool from this (uncooled) state,
The reverse of the current procedure may be performed, and further description will be omitted.

In the present embodiment, the laminar flows 23a to 23f are ejected and stopped in this manner. The laminar flows 23a to 23f are ejected to the hot-rolled steel strip 11 by the through holes formed in the blocking plate 31. Since the operation is performed via 32a to 32f, the laminar flows 23a to 23f can be ejected and stopped by a minute operation of the blocking plate 31. Therefore, as compared with the cooling device described in Japanese Patent Publication No. 45-29891, for example, the responsiveness of the laminar flows 23a to 23f with respect to jetting and stopping can be remarkably improved. Thereby, the reverse U
The uniformity and responsiveness of the timing of jetting and stopping the cooling water from the letter-shaped nozzles 21a to 21f can be improved, and the accuracy of cooling the hot-rolled steel strip 11 can be improved. In this manner, the hot-rolled steel strip 11 can be cooled to a desired temperature while minimizing nonuniformity in temperature in the width direction.

(Second Embodiment) Next, a steel strip cooling device 50 according to a second embodiment will be described in detail with reference to the accompanying drawings. The description of the steel strip cooling device 50 of the present embodiment will be described in the first section.
Only the portions different from the steel strip cooling device 10 of the embodiment will be performed, and the common portions will be denoted by the same reference numerals in the drawings, and the common description will be omitted. FIG.
FIG. 3 is an explanatory view showing a steel strip cooling device 50 of the present embodiment and a state of the steel strip cooling using the steel strip cooling device 50.

The difference between the steel strip cooling device 50 of the present embodiment and the steel strip cooling device 10 of the first embodiment is that both ends of the collision surface (upper surface) of the shut-off plate 31 with the laminar flows 23a to 23f are provided. Where the cooling plate 31 is in the non-blocking position and where the supercooling occurs in the hot-rolled steel strip 11 in the laminar flows 23a to 23f (in this embodiment, about 5% of the both ends in the width direction of the steel strip). The gas injection devices 51a and 51f that can inject gas into the laminar flows 23a and 23f are installed as a cooling water flow blocking mechanism that shuts off the laminar flows 23a and 23f that directly affect the cooling of It is.

In the present embodiment, air injection nozzles 51a and 51f are installed as gas injection devices, and the air injection nozzles 51a and 51f are provided.
By jetting an air jet stream from 51f, only the path of the columnar laminar streams 23a and 23f jetted toward both ends in the width direction of the hot-rolled steel strip 11 is changed.

In the present embodiment, since the blocking plate 31 used in the first embodiment is used, the position change of the blocking plate 31 when the laminar flows 23a to 23f are ejected and stopped is very small.
In both the blocking position B and the non-blocking position A, the distal end of the blocking plate 31 is positioned above the opening of the drain gutter 41, that is, the position where the cooling water flowing on the surface of the blocking plate 31 flows down to the drain gutter 41. Can always be present.

Therefore, even when the blocking plate 31 is in the non-blocking position A, the laminar flows 23a and 23f are dropped by ejecting the air jets from the air injection nozzles 51a and 51f toward the laminar flows 23a and 23f. The direction can be changed and through holes 32a, 32f
And can collide with the blocking plate 31. In this manner, the cooling water flows down along both side edges of the blocking plate 31 and is received by the drain gutter 41.

Therefore, in FIG. 5, the laminar flows 23b to 23e are ejected only from the through holes 32b to 32e formed on the inner side of the blocking plate 31, and the inside of the hot rolled steel strip 11 in the width direction is cooled. However, cooling of both ends in the width direction of the hot-rolled steel strip 11 is not performed. In this way, the widthwise both ends of the hot-rolled steel strip 11 are weakly cooled as compared with the inner side, so that the unevenness in the widthwise temperature distribution of the hot-rolled steel strip 11 is suppressed / eliminated.
Thereby, the overcooling of the hot rolled steel strip 11 at the time of cooling is suppressed or eliminated.

[0043]

EXAMPLES The effects of the steel strip cooling apparatus according to the present invention will be described more specifically based on experimental data. FIG.
Is a hot-rolled steel strip at the exit of the finishing mill (sheet thickness 5.7 mm, sheet width
(1600 mm) is a graph showing an example of a change with time of the surface temperature.

As shown in the graph of FIG. 6, the hot-rolled steel strip in a high-temperature state is placed in a high-temperature range of 10 m on the inlet side of a steel strip cooling device provided on a hot run table having a total length of 80 m.
Control cooling was performed by applying the steel strip cooling device 50 according to the present invention shown in FIG. 5, and the time-dependent change in the winding temperature and the temperature distribution in the sheet width direction were measured.

On the other hand, the above-described hot rolled steel strip was cooled using a conventional steel strip cooling apparatus not provided with the blocking plate 31, the drain gutter 41 and the air injection nozzles 51a and 51f, and the same measurement was performed.
The response time of the header was measured for each of the steel strip cooling device according to the present invention and the conventional steel strip cooling device. The results are summarized in Table 1.

[0046]

[Table 1]

From Table 1, it can be seen that the steel strip cooling apparatus according to the present invention was able to significantly reduce the response time of the header, and was able to significantly improve the responsiveness of cooling water jetting and stopping. Fig. 7 shows the measurement results of the change over time in the winding temperature.
FIG. 7 (a) shows a graph, and FIG.
(b) shows a graph.

From the graph shown in FIG. 7 (a), it can be understood that the steel strip cooling device according to the present invention has made the winding temperature of the hot-rolled steel strip uniform and improved the cooling accuracy. This is because the response of the header is improved by the present invention.

From the graph shown in FIG. 7 (b), the cooling capacity at both ends in the width direction of the hot-rolled steel strip is compared with that at the inner side by 50-70.
It can be seen that the percentage was reduced by about%. Therefore, the temperature difference in the width direction during cooling of the hot-rolled steel strip could be suppressed within 10 ° C. Thereby, the ear wave deformation was eliminated.

[0050]

[Modification] In the steel strip cooling device of each embodiment, the case where six inverted U-shaped nozzles are installed in the width direction of the steel strip is shown, but the steel strip cooling device according to the present invention is limited to such an embodiment. Instead, it may be set as appropriate in accordance with the capacity required for the cooling device.

Further, in the steel strip cooling device of each embodiment, a case is shown in which four inverted U-shaped nozzle groups are arranged side by side in the steel strip transport direction (see FIG. 1). The zone cooling device is not limited to such an embodiment, and may be appropriately set in accordance with the capacity required of the cooling device. Usually, about 200 units are installed.

Further, in each of the embodiments, the rotary shaft and the air cylinder are used for operating the blocking plate. However, the present invention is not limited to such an embodiment. For example, by installing an air cylinder or a robot arm directly on the blocking plate, the blocking plate may be operated linearly, curvedly, or a combination thereof.

Further, in each of the embodiments, the case where the columnar cooling water flow is jetted toward the steel strip has been described. However, the present invention is not limited to such an embodiment. Also includes the case of spouting.

Further, in the second embodiment, as the cooling water flow blocking mechanism, the gas injection device installed on the blocking plate is used. However, the steel strip cooling device according to the present invention is not limited to such a mode. Instead, for example, any material may be used as long as it can close a part of the through-hole, such as a slidable through-hole closing plate disposed on the blocking plate.

[0055]

According to the steel strip cooling device of the present invention,
The responsiveness of the cooling water ejection start timing and the stop timing and the uniformity of the temperature distribution in the width direction can all be remarkably improved. Further, the steel strip cooling device according to the present invention can be easily applied to existing equipment at low cost,
By cooling the steel strip uniformly in the width direction to a predetermined temperature, it is possible to eliminate the appearance defect at the end in the width direction of the steel strip. Therefore, according to the steel strip cooling device according to the present invention, the quality of the steel sheet and the yield can be significantly improved. The significance of the present invention having such an effect is extremely remarkable.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a main part of a steel strip cooling device according to a first embodiment and partially showing the main part in a see-through state.

FIG. 2 is an explanatory view showing a drive unit of a rotating shaft of the steel strip cooling device in the first embodiment.

FIG. 3 is an explanatory view showing the steel strip cooling device in the first embodiment when the steel strip is cooled.

FIG. 4 is an explanatory view showing the steel strip cooling device in the first embodiment when the steel strip is not cooled.

FIG. 5 is an explanatory diagram showing a steel strip cooling device according to a second embodiment and a state of the steel strip cooling using the steel strip cooling device.

FIG. 6 is a graph showing an example of a change with time of a surface temperature of a hot-rolled steel strip used in an example at an outlet of a finishing mill.

FIGS. 7 (a) and 7 (b) are graphs respectively showing a change over time in a winding temperature and a temperature distribution in a sheet width direction in Examples.

FIG. 8 is a schematic explanatory view showing a controlled cooling process of a hot-rolled steel sheet.

9A and 9B are explanatory views showing a top surface cooling device using a pipe laminar method, wherein FIG. 9A is a vertical sectional view at the center position in the width direction of the steel strip, and FIG. FIG.

[Explanation of symbols]

 11 Steel strip 21a to 21f Nozzle 23a to 23f Cooling water flow 31 Shut-off plate 32a to 32f Through hole 41 Drain gutter 50 Steel strip cooling device 51a, 51f Gas injection nozzle

Claims (7)

[Claims] 1. A cooling device for a steel strip to be conveyed, comprising: a plurality of nozzles arranged in parallel in a width direction of the steel strip and for jetting a plurality of cooling water flows toward a surface of the steel strip; A blocking member variably disposed between a blocking position where the cooling water flow collides with the cooling water flow to block the cooling water flow and a plurality of non-blocking positions not colliding with the cooling water flow, and the blocking member positioned at the blocking position And a drain mechanism for receiving cooling water flowing down by colliding with the blocking member and discharging the cooling water to the outside of the system, wherein the blocking member allows the cooling water flow to pass when in the non-blocking position. A steel strip cooling device characterized by having a plurality of through holes. 2. A cooling device for a conveyed steel strip, comprising: a plurality of nozzles arranged side by side in a width direction of the steel strip and for jetting a plurality of cooling water flows toward a surface of the steel strip; A blocking member variably disposed between a blocking position where the cooling water flow collides with the cooling water flow to block the cooling water flow and a plurality of non-blocking positions not colliding with the cooling water flow, and the blocking member positioned at the blocking position A drainage mechanism that is disposed below and receives cooling water that collides with the blocking member and flows down and discharges the cooling water to the outside, and when the blocking member is in the non-blocking position, A cooling device for cooling a steel strip, comprising: a cooling water flow cutoff mechanism that causes the cooling water flow that directly affects the cooling of a portion of the steel strip where supercooling occurs to flow to the drainage mechanism. 3. The cooling water flow shut-off mechanism is a gas injection device that injects gas into the cooling water flow that directly affects the cooling of a portion where the supercooling occurs. The steel strip cooling device as described in the above. 4. The blocking member has a plurality of through holes through which the cooling water flow passes when in the non-blocking position, and at a position where the gas guides the cooling water injected and flows down to the drainage mechanism. The steel strip cooling device according to claim 3, wherein the steel strip cooling device is a plate-shaped member that is located. 5. The steel strip cooling according to claim 2, wherein the cooling water flow blocking mechanism is provided on a surface of the blocking member that collides with the cooling water flow. apparatus. 6. The apparatus according to claim 1, wherein the change of the blocking position and the non-blocking position of the blocking member is performed by a rotational movement about the vicinity of an end of the blocking member as a rotation center. The steel strip cooling device according to any one of the preceding items. 7. The drainage gutter according to claim 1, wherein the drainage mechanism is a drainage gutter installed over the steel strip in a width direction of the steel strip. 2. The steel strip cooling device according to claim 1.