JP4061286B2 - Metal plate cooling device and cooling method - Google Patents

Description

  The present invention relates to cooling of a metal plate (meaning a steel plate, a titanium plate, a copper plate, etc., hereinafter referred to as “metal plate”) having a temperature of several hundred degrees or more during conveyance in a hot rolling process or a heat treatment process. The present invention relates to a metal plate cooling device and a cooling method applied to obtain a metal plate having good shape characteristics and uniform material.

For example, hot-rolled high-temperature steel sheets are cooled when transported to a winding or pickling process, and it is important to ensure uniform material characteristics and shape characteristics (flatness). Therefore, it is necessary to perform the controlled cooling so that the temperature distribution in the plate width direction is particularly uniform.
As a cooling device for performing such cooling, for example, Patent Document 1 discloses a cooling device that has a number of nozzle injection holes for injecting a cooling medium and is installed in parallel with the conveying direction of the steel material. ,
(1) Arrange in a skewed manner with respect to the transport direction.
(2) Arrange so that the projections of adjacent nozzle injection holes overlap.
(3) A nozzle group in which slit nozzles or nozzle injection holes are densely arranged in the width direction at a predetermined interval is provided on a part or the entire surface of the surface having nozzle injection holes in the transport direction.
(4) The nozzle injection holes adjacent in the conveyance direction are overlapped and arranged so that the minimum number of passages per unit time passing through the region immediately below the nozzle injection holes of the steel sheet is changed depending on the conveyance speed.
The present invention is intended to improve the mechanical properties, workability, weldability, residual stress characteristics, etc. of steel materials by eliminating the uneven cooling of the steel materials and also capable of uniformly cooling the steel materials having a high conveyance speed. Proposed.
However, all of the inventions of (1) to (4) in Patent Document 1 are cooling devices in which a large number of small diameter nozzles of 3 to 4 mm are arranged at intervals of 15 to 30 mm, and are arranged in multiple rows in the transport direction. Therefore, there are problems such as an increase in equipment burden, frequent troubles such as nozzle clogging, and poor sustainability of stable refrigerant injection. In addition, since the refrigerant injection flow is a small-diameter rod-like flow and the cooling area is small, it is necessary to arrange a large number of refrigerant injection nozzles densely and to inject the refrigerant at high pressure, especially when rapidly cooling high-temperature steel materials. The above problem becomes more prominent.

Further, in Patent Document 2, by disposing refrigerant injection spray nozzles densely at least in the steel material conveyance direction, the injection areas of refrigerant injection spray nozzles adjacent in the steel material conveyance direction partially overlap to form an injection interference area. Thus, it has been proposed that the hot steel material is cooled by the refrigerant jet spray in which the substantially uniform and continuous jet interference area is formed in the direction perpendicular to the steel material conveyance.
In addition, when a long jet interference zone is formed in the transport direction, the cooling capacity increases between the spray nozzles adjacent to each other in the steel transport orthogonal direction, and a uniform cooling capacity cannot be obtained in the steel width direction. It has also been proposed to obtain a uniform cooling performance by providing baffle plates extending in the steel material conveyance direction between spray spray nozzles adjacent to each other in the conveyance orthogonal direction.
The spray nozzle used here is, for example, a conventional general nozzle (preferably having an injection angle of 90 degrees or less) for injecting refrigerant in a conical shape. Although it is attractive to arrange, since the refrigerant is injected in a full conical shape with a spread angle α from the structure, the cooling capacity distribution is normal injection at the collision surface between the refrigerant amount distribution and the thick steel plate of the refrigerant droplets It will be affected by the velocity distribution. For example, even when the refrigerant amount distribution is uniform, when the jet flow spread angle α is 90 degrees, for example, the normal direction injection speed of the peripheral portion of the refrigerant jet flow is 30% as compared with the central portion. descend.
Therefore, as long as the jet velocity distribution in the normal direction exists, the cooling capacity distribution is not uniform in the diameter direction of the refrigerant collision surface, that is, the width direction of the thick steel plate, and the temperature change width in the width direction of the thick steel plate is considerably large. Become a thing.
In Patent Document 2, it seems that the cooling ability can be ensured by reducing the influence of the normal direction injection speed by forming the injection interference area by densely arranging in at least the steel material conveying direction, but adjacent to each other. Refrigerant stagnation occurs between the injection interference areas between the spray spray nozzles, resulting in insufficient convection, and water that is not discharged disturbs the jet itself, resulting in poor uniformity, or cooling efficiency is not sufficient and cooling cost There is also a problem that increases.
JP 2001-232413 A JP-A-8-238518

  In the present invention, a refrigerant (water, air, a mixture of water and air, a cooling medium represented by a molten salt, etc., hereinafter abbreviated as “refrigerant”) is jetted onto a metal plate being conveyed. In the metal plate cooling device in which the full cone spray nozzles are arranged vertically in a plurality of rows in the width direction and in the conveying direction, the arrangement of the refrigerant injection nozzles is reduced to reduce the equipment cost burden, and the metal plate surface A cooling apparatus and cooling method for a metal plate that can easily achieve low-cost uniform cooling in the width direction of the metal plate by improving the cooling efficiency by making the collision, convection and flow / discharge of the injected refrigerant in a favorable state It is.

The metal plate cooling device according to the present invention has the following configurations (1) to (4) in order to efficiently realize uniform cooling in the width direction of the metal plate.
(1) A cooling cone provided with a plurality of pairs of restraining rolls for restraining and passing a metal plate, and having a filling cone spray nozzle capable of controlling the amount of refrigerant injected between each pair of restraining rolls. The spray nozzles are vertically arranged in multiple rows in the width direction of the metal plate and in the transport direction, and the full cone spray nozzles are arranged apart so that the collision surface of the injected refrigerant does not interfere with the metal plate surface. In addition, when the refrigerant jet flow from each full cone spray nozzle is projected from the conveyance direction onto a vertical plane orthogonal to the conveyance direction of the metal plate, the refrigerant jet flow of the full cone spray nozzle adjacent in the conveyance direction of the metal plate Is arranged so as to be partially overlapped and projected on the vertical surface in the width direction, and as the full cone spray nozzle, a full cone spray having a refrigerant spray spread angle of 5 to 40 degrees. -A metal plate cooling device using a nozzle .
(2) In (1) , the width of the overlap of the refrigerant jet flow between the full cone spray nozzles adjacent in the conveying direction of the metal plate is the bottom diameter of the vertical plane of the refrigerant jet flow of both full cone spray nozzles The metal plate cooling device characterized by being 0.4 times or more.
(3) (1) or Oite, in units between each constraining roll pair (2), the collision surface of the coolant jet from KakuTakashi cone spray nozzles, partially overlap in the width direction of the projection vertical surface A plurality of nozzle rows are arranged so as to cover the entire width of the metal plate.
(4) The cooling device for the metal plate according to any one of (1) to (3) is arranged so that the metal plate in the restraining passage plate can be cooled by a plurality of pairs of restraining rolls, and from the full cone spray nozzle of the cooling device. A method for cooling a metal plate, wherein the metal plate is cooled by a jetting refrigerant of the above, and the uniformity of the temperature distribution in the width direction of the metal plate after cooling is improved.

  In the metal plate cooling apparatus according to the present invention, a full conical spray nozzle capable of injecting a refrigerant in a wide range is used. Therefore, the equipment cost burden can be reduced with a small nozzle arrangement, and the jet spread angle α is set to 5 to 40 degrees. A plurality of full-cone spray nozzles having a variation width of the jet velocity distribution in the normal direction of 5% or less are arranged apart from each other so that the refrigerant collision surface does not interfere in the width direction and the conveyance direction of the metal plate, and By arranging the conical spray nozzles adjacent in the transport direction so that the refrigerant collision surfaces partially overlap in the width direction, the number of nozzles is reduced and the cooling efficiency is improved. For example, when the metal plate is a steel plate, the surface temperature distribution width in the width direction is reduced to about 20 ° C. to stabilize the shape characteristics. , It is possible to obtain a steel sheet having a surface layer structure.

When used for cooling a steel sheet, the metal plate cooling device of the present invention is arranged at the subsequent stage of the hot rolling mill 2 as shown in FIG. 1, for example, and basically includes a plurality of restraining rolls. (For example, 4a, 4b, 4c) and nozzle row groups 1a, 1b, 1c arranged between the pair of restraining rolls (for example, between 4a and 4b, between 4b and 4c). The jet refrigerant from the above has a structure for cooling the steel sheet restrained and transported between each pair of restraining rolls. For example, a high temperature of 700 to 1000 ° C. obtained by hot rolling with the hot rolling mill 2 is used. This is particularly effective when applied to control and cool the steel plate 3 to room temperature to 700 ° C. during conveyance.
In the nozzle row groups 1a, 1b, and 1c of the cooling device 1 for the metal plate (steel plate), as shown in FIGS. 2 (a) and 2 (b), the refrigerant collision surface with the steel plate 3 is circular as shown in FIGS. As shown in FIGS. 3 and 4, a nozzle 5 (hereinafter referred to as a “full cone spray nozzle”) that forms a refrigerant injection flow 5 a that can disperse and collide with the refrigerant in a wide range as shown in FIGS. 3 and 4. The collision surfaces are separated so as not to interfere with each other on the steel plate 3, for example, a plurality (rows) are arranged at intervals a in the width direction of the steel plate 3 and at intervals b in the transport direction.

Here, for example, the nozzle row group 1a between constraining roll pair (e.g. between 4a and 4b) are adjacent in the conveying direction of the steel plate 3, for example, the first column of the charge cone spray nozzles 5 ₁ and the second column charging cone spray nozzles 5 ₂ eyes, between both refrigerant jet 5a when viewed from the conveying direction of the steel plate 3, is to arranged to partially overlap.
For example, as shown in FIG. 5, projecting a refrigerant jet 5a from charging cone spray nozzles 5 ₁ and 5 ₂ adjacent in the conveying direction of the steel sheet 3, a vertical plane F perpendicular from the transport direction to the transporting direction of the steel plate 3 in case of the shape of the charge-cone spray nozzle 5 ₁ and 5 ₂ of the coolant jet 5a, is to arranged to be partially overlapping with the projection on the steel plate 3 surface.
By adopting such a nozzle arrangement, it is possible to reduce the number of nozzle arrangements and improve the cooling efficiency, and in particular, in the width direction of the steel plate 3, the refrigerant collision surface that governs the cooling capacity is stably formed, and the refrigerant collision area distribution is reduced. The uniformity is increased to enhance the cooling uniformity, the change width of the temperature distribution in the width direction of the steel sheet 3 is set to 20 ° C. or less, and the shape characteristics and material characteristics of the steel sheet 3 can be homogenized .

Hereinafter, the present invention will be specifically described with reference to FIGS. Here, forming the nozzle row groups 1a of the cooling device 1 of the steel sheet, leading described in example charging cone spray nozzle ₂ of 5 of the first column of the charge cone spray nozzles 5 ₁ and the second column in the transport direction.
The full conical spray nozzles (5 ₁ , 5 ₂ ) are arranged on the upper surface side and the lower surface side of the steel plate 3 so as to cool the upper and lower surfaces of the steel plate 3, but here, the cooling on the upper surface side will be described. The description of the cooling on the lower surface side is omitted.
In terms of cooling on the lower surface side, conceptually, by arranging the full conical spray nozzles (5 ₁ , 5 ₂ ) in the same manner as on the upper surface side, uniform cooling in the width direction of the steel plate is possible on the lower surface side. However, since the behavior of the refrigerant injection flow is different from that on the upper surface side, regarding cooling on the lower surface side, consideration is given to the addition of conditions for ensuring cooling on the upper surface side and a preferable cooling balance.

In the present invention, the full cone spray nozzles (5 ₁ , 5 ₂ ) forming the nozzle row groups 1a, 1b, 1c of the steel sheet cooling device 1 can inject a refrigerant in a wide range, and therefore can be arranged with a small number of nozzles. Although attractive, the refrigerant is jetted into a full conical shape with a spread angle α from the structure, so the cooling capacity distribution affects the normal velocity jet velocity distribution at the collision surface between the refrigerant amount distribution and the steel sheet of the refrigerant droplets. Will receive.
For example, even if the refrigerant amount distribution is uniform, as shown in FIGS. 6A and 6B, when the refrigerant jet spread angle α is, for example, 90 degrees, injection is performed at the periphery of the refrigerant jet flow 5a. The speed is reduced by 30% compared to the center. As long as such an injection velocity distribution in the normal direction exists, it is avoided that the cooling capacity distribution becomes non-uniform in the diameter direction of the refrigerant collision surface, that is, the width direction of the steel plate 3, and the temperature change width in the width direction of the steel plate 3 is generated. I can't.

Accordingly, in the present invention, the jet spread angle α of the refrigerant of the full cone spray nozzle (5 ₁ , 5 ₂ ) is reduced to reduce the change in the injection speed in the normal direction to 5% or less, thereby alleviating the non-uniformity of the cooling capacity distribution. Consider what to do.
The jet spread angle α for making the change in jet velocity in the normal direction 5% or less is 40 degrees or less from FIG. 6A, but if the jet spread angle α is less than 5 degrees, the refrigerant governing the cooling capacity. Since the area of the collision surface becomes small, it is necessary to increase the number of nozzles arranged, resulting in the problems described above. In addition, when the jet spread angle α is more than 40 degrees, the non-uniformity of the refrigerant jet velocity distribution in the normal direction cannot be sufficiently mitigated, so that it is necessary to increase the overlap width d. There is a concern that a refrigerant flow that can ensure stable cooling efficiency cannot be formed. Therefore, the jet spread angle α is preferably 5 to 40 degrees .

As described above, the full-cone spray nozzles 5 ₁ , 5 ₂ that have relaxed the uneven cooling capacity distribution in the normal direction are spaced apart in the width direction of the steel plate 3 as shown in FIGS. , also at a distance b in the conveying direction, but in which each of a plurality of arrangement, for example, when viewed in the first nozzle row including a plurality of charge cone spray nozzles 5 _1, in the width direction of the steel plate 3 There is a region injected refrigerant between the refrigerant collision surface between KakuTakashi cone spray nozzles 5 ₁ adjacent do not collide, since this region has no conflicts injection refrigerant governing the cooling effect, the first nozzle row KakuTakashi cone spray nozzle 5 ₁ only becomes noticeable uneven cooling capacity distribution in the width direction of the steel plate 3.
Therefore, the charge cone spray nozzle 5 of the _second nozzle row including a plurality of charge cone spray nozzles 5 ₂ adjacent in the conveying direction of the steel plate 3, the refrigerant impact surface that is in the first nozzle row at a position apart by a distance b which does not interfere with the charging cone spray nozzles 5 ₁ coolant impact surface, be arranged to be formed in the region there is no refrigerant collision charging cone spray nozzles 5 of the _first nozzle row This increases the uniformity of the refrigerant collision area distribution in the width direction of the steel plate 3 by the first and second nozzle rows, and alleviates the non-uniformity of the cooling capacity distribution in the width direction of the steel plate 3. .
The distance a in the width direction of the charging cone spray nozzles 5 _1, 5 ₂ of the steel plate 3, the degree obtained by subtracting the width d min of the overlap than the diameter D of the coolant impact surface of the steel plate 3 of both the refrigerant jet 5a distance b between the conveying direction between, and also charge cone spray nozzles 5 ₁ and 5 _2, the flow of discharging the injected refrigerant in order not to interfere with the refrigerant impinging flow, it is preferable to separate more than 60% of the distance a.

In the first row and between charging cone spray nozzles 5 ₁ and 5 ₂ of the second nozzle row adjacent to each other in the conveyance direction of the steel plate 3, as shown in FIG. 5, the charge cone spray nozzles 5 ₁ and 5 ₂ When the refrigerant jet shape is projected from the conveying direction onto the vertical plane perpendicular to the conveying direction of the steel plate 3, the full cone spray nozzle 5 is projected so as to partially overlap the lower side in the width direction. is intended to place the ₁ and 5 _2, due to the normal direction of the injection velocity distribution change of the refrigerant impact surface during charge cone spray nozzles 5 _1, 5 _2, unevenness in cooling capacity distribution for the width direction of the steel plate 3 It is preferable to further relax.
The degree of the overlap width d depends on the jet spread angle α of the full cone spray nozzle. For example, when the jet spread angle α is 5 to 40 degrees and the change in the refrigerant injection speed is less than 5%. , the flow of refrigerant jetted collide with the steel plate 3 surface, in order to flow discharged in the flow can be stably ensured cooling efficiency, the width d of the overlap, charge cone spray nozzles 5 ₁ and 5 ₂ of the coolant jets 5a Is preferably 0.4 times or more the bottom surface diameter D of the refrigerant jet 5a on the vertical plane F when projected from the transport direction onto the vertical plane F orthogonal to the transport direction of the steel plate 3. Here, the bottom diameter D of the refrigerant jet 5a corresponds to the diameter D of the collision surface of the refrigerant jet 5a with the surface of the steel plate 3 .

Figure 7 is for the meaning of the width d of the overlapping of the coolant impact surface between the charge cone spray nozzles adjacent the conveying direction of the steel sheet in the present invention (5 ₁ and 5 ₂₎ shown in a plan view, wherein Then, for convenience, the refrigerant collision surfaces of the refrigerant jet flow 5a and the steel plate 3 are shown side by side in the same position, and FIG. 7 (a) shows the overlap width d in FIG. 0.4 times the base diameter D of the coolant jet 5a in terms F, i.e., the overlap ratio between the refrigerant collision surfaces of adjacent charge cone spray nozzles 5 ₁ and 5 ₂ of the coolant jet 5a in the conveyance direction of the steel plate 3 FIG. 7B shows a case where (d / D) is 0.4, and FIG. 7B shows a case where the overlap width d is ½ or more of the bottom surface diameter D, for example 2/3.
The width d of the overlap is to influence the jet spread angle alpha, the magnitude of the cooling capacity of the injection refrigerant from the charge cone spray nozzle (5 ₁ and 5 _2). The cooling capacity of each part in the transport direction can be obtained using the bottom surface diameter D, the overlap width d (or the overlap angle θ), and the jet spread angle α.

8, the overlap width d and a bottom surface diameter D ratio (overlap ratio: d / D) of between refrigerant impact surface charge cone spray nozzles adjacent to each other in the conveying direction (5 ₁ and 5 ₂₎ and, the cooling capacity The relationship between the maximum and minimum ratios (-) is shown separately when the jet spread angle α of the full cone spray nozzle is 5, 40, 60, and 100 degrees.
Here, the maximum and minimum ratio of the cooling capacity (-) and, between the center of the refrigerant impact surface charge cone spray nozzles adjacent to each other in the conveying direction (5 ₁ and 5 _2), the overlapping of the coolant collision surface ratio: d / D The cooling capacity distribution width in the width direction of the steel plate 3 that changes depending on the ratio is shown as a ratio to the maximum cooling capacity (the cooling capacity at the center of the refrigerant collision surface).
From FIG. 8, when the jet spread angle α of the full cone spray nozzle is 5 degrees and 40 degrees, the overlap ratio (d / D) is 0.4 or more with respect to the maximum cooling capacity when the overlap ratio (d / D) is 0.4. It shows that the cooling capacity can be secured and the change width of the cooling capacity distribution in the width direction of the steel plate 3 can be relaxed to 10% or less. By arranging the adjacent full cone spray nozzles so that the change width of the cooling capacity distribution is 10% or less, the change width of the surface temperature distribution in the width direction of the steel sheet 3 after cooling can be 20 ° C. or less.
When the overlap ratio (d / D) is set to 0.35, even if the jet spread angle α of the full cone spray nozzle is 5 degrees, only about 0.8 cooling capacity can be secured with respect to the maximum cooling capacity. This indicates that the change width of the cooling capacity distribution in the width direction of the steel plate 3 cannot be 10% or less, and it is difficult to set the change width of the surface temperature distribution in the width direction of the steel plate 3 after cooling to 20 ° C. or less.

When the jet spread angle α of the full cone spray nozzle is 60 degrees or 100 degrees, even if the overlap ratio (d / D) is 0.4, the cooling capacity is only about 0.8 with respect to the maximum cooling capacity. Since it cannot ensure, it has shown that the change width of the cooling capacity distribution in the width direction of the steel plate 3 cannot be made 10% or less. If the angle α is 60 degrees or 100 degrees and the overlap ratio (d / D) is increased to about 0.7, a cooling capacity of about 0.95 with respect to the maximum cooling capacity can be secured. As a result, a large number of full-cone spray nozzles are arranged, increasing the cost burden.
From these things, it can be said that it is more preferable that the jet spread angle α is 5 to 40 degrees and the overlap ratio (d / D) is about 0.4 to 0.7.

In the above example, the first column of the charge cone spray nozzles 5 ₁ and the second column of the charge cone spray nozzles 5 ₂ in the transport direction of the steel plate 3, the overlapping width arranged in parallel in the direction perpendicular to the conveying direction d is formed, but the first nozzle row and the second nozzle row are alternately arranged according to the steel plate conditions (material, size, temperature) to be cooled, cooling conditions, etc. Further, it is possible to consider an increase in the arrangement of nozzle rows such as the third row and the fourth row in the conveying direction of the steel plate 3.
In particular, when cooling the high-temperature steel plate 3, from the viewpoint of preventing warpage and homogenizing the surface layer structure, the first nozzle row for cooling the steel plate 3 first is the second nozzle row. It is often advantageous to form a larger number of full-cone spray nozzles and uniformly cool a wide area in the width direction, but the first row of nozzles is less than the second row of nozzles. It is also possible to consider forming with a full cone spray nozzle.
Thus, the collision surface of the plurality of nozzle arrays of charge cone spray nozzles 5 _1, 5 ₂ refrigerant jets 5a, as the plurality of nozzle rows arranged in the case of collision in the entire width direction of the steel plate 3, for example, in FIG. 1 As described above, when a plurality of pairs of restraining rolls 4a, 4b, and 4c are provided, the nozzle array group 1a is disposed between the restraining rolls 4a and 4b, and the nozzle array group 1b is disposed between the restraining rolls 4a and 4b. Although it can be considered that the total number of constraint roller pairs, that is, the total of the nozzle row group 1a and the nozzle row group 1b, it is desirable to consider each constraint roller pair unit, that is, each nozzle row group unit.
This is because when the steel plate 3 is cooled, the cooling capacity changes with the change in the surface temperature of the steel plate 3, for example, between the nozzle row group 1a arranged between the restraining rolls 4a and 4b and the restraining rolls 4b and 4c. Even if the collision surface of the refrigerant jet 5a of the nozzle row group 1b arranged at the same position is collided with the entire width direction of the steel plate 3, the surface temperature of the steel plate 3 is greatly different in the traveling direction of the steel plate 3. This is because there is a difference in cooling capacity between the restraining rolls 4b and 4c, and the uniformity of cooling in the width direction is deteriorated .

The cooling device 1 of the metal plate of the present invention configured as described above is disposed in the cooling zone of the hot rolling line for steel plates shown in FIG. In addition, the full cone spray nozzles 5 ₁ , 5 ₂ having a refrigerant jet spread angle α of, for example, 5 to 40 degrees are arranged so that the refrigerant collision surface (overlap ratio d) in the conveying direction of the steel plate 3 as shown in FIG. / D: 0.4) When the steel plate 3 is cooled by the jet refrigerant from the full conical spray nozzles 5 ₁ , 5 ₂ , the steel plate 3 is arranged in the width direction. The variation width of the cooling capacity distribution is 10% or less. For example, when the cooling capacity distribution is cooled to a temperature of 800 to 400 ° C., as shown in FIG. It is possible to ensure stability, and the change width of this temperature distribution is set to 20 ° C or less. It can, warp without shape characteristics are good, it is possible to stably ensure the uniformity of the surface layer structure obtaining the steel sheet with no reduction factor of the mechanical properties. (Corresponding to the embodiment of claim 5).

In addition, as shown in FIG. 10, the range which the refrigerant | coolant collision surface with the steel plate 3 of the refrigerant | coolant injection flow 5a does not interfere (overlap) through the full cone spray nozzles 5 ₁ and 5 ₂ similar to the case of FIG. 9A. When the steel plate 3 is cooled by spraying the same amount of refrigerant (water), the change width of the cooling capacity distribution in the width direction of the steel plate 3 is 100%, for example, cooled to a temperature of 400 ° C. The change width of the surface temperature distribution in the width direction of the subsequent steel plate 3 is 60 ° C. or more, and it is not possible to obtain a steel plate that can sufficiently satisfy the shape characteristics and the uniformity of the surface layer structure.

Further, as shown in FIG. 11, the full conical spray nozzles 5 ₁ , 5 ₂ similar to the case of FIG. 9A have a refrigerant collision surface of 1/4 (overlap ratio d / D: in the conveying direction of the steel plate 3). 0.25) When the steel plate 3 is cooled by the jet refrigerant from the full conical spray nozzles 5 ₁ , 5 _{2 when} arranged in a positional relationship that causes interference (overlap), the cooling capacity distribution in the width direction of the steel plate 3 The width of change in the surface temperature distribution in the width direction of the steel sheet 3 after cooling to a temperature of 400 ° C., for example, is 35 ° C. or more, and the shape characteristics and the uniformity of the surface layer structure are sufficiently satisfied. A steel plate cannot be obtained.

As shown in FIG. 1, a jet spreading angle α during the conveyance of a steel plate 3 having a surface temperature of 750 to 770 ° C. and a thickness of 30 mm and a width of 3200 mm hot-rolled by a hot finish rolling mill 2 as shown in FIG. Is sprayed with water at a jetting pressure of 0.2 MPa from the cooling device 1 of the present invention in which the conical spray nozzles 5 ₁ , 5 ₂ of 30 degrees are arranged as shown in FIGS. Then, immediately after passing through the cooling zone, the target temperature was 390 to 410 ° C.
The full cone spray nozzles 5 ₁ and 5 ₂ used here have the same characteristics, the arrangement interval a in the width direction of the steel plate is 60 mm, the arrangement interval b in the conveyance direction is 80 mm, and the tip of the nozzle is the surface of the thick steel plate 3. The diameter D of the collision surface with the thick steel plate 3 of the jet water is 40 mm, and the overlap width d is 16 mm (d / D: 0.4). The amount of water sprayed from each full cone spray nozzle was 20 liters / minute per nozzle.
As a result, the change width of the surface temperature distribution in the width direction of the steel sheet 3 cooled to 400 ° C. was about 20 ° C., and the shape characteristics were satisfactory without warping. Further, when a sample was collected and analyzed for texture, the uniformity of the surface structure was sufficiently satisfactory, and no reduction factor of mechanical properties was observed.

In addition, this invention is not limited to said content. For example, although the above has mainly described the case where the object to be cooled is a steel plate, the application of the present invention can be considered even if another metal plate, for example, a titanium plate, a copper plate, or the like is the object to be cooled.
In addition, the structure condition, arrangement condition, refrigerant injection condition, etc. of the full cone spray nozzle include the metal plate conditions (material, size, temperature) to be cooled, the surface quality, shape, mechanical properties, etc. required for the metal plate. Depending on the cooling conditions set in consideration, there is a change within a range satisfying the above claims.

Side surface explanatory drawing which shows the example of arrangement | positioning of the cooling device of the steel plate to which this invention is applied. (A) The figure is a three-dimensional conceptual explanatory diagram showing an example of the shape of a full-cone spray nozzle and a refrigerant jet forming the steel plate cooling device of the present invention, and (b) is an injection from the full-cone spray nozzle of FIG. Explanatory drawing which shows the collision surface shape example with the steel plate surface of the made refrigerant jet. Plane | planar explanatory drawing which shows the example of arrangement | positioning of the full cone spray nozzle in the cooling device of the steel plate by this invention. Side surface explanatory drawing of FIG. In the arrangement example of the full cone spray nozzle of FIG. 3, the refrigerant injection on the vertical plane F when the refrigerant jet shape from the adjacent full cone spray nozzle is projected from the conveyance direction onto the vertical plane F orthogonal to the conveyance direction. The conceptual explanatory drawing which shows the example of a shape. (A) The figure is explanatory drawing which shows the relationship between the spreading angle (alpha) of the refrigerant jet of a full cone spray nozzle, and the speed ratio of the steel plate normal direction of a refrigerant jet, (b) A figure is the refrigerant jet in a full cone spray nozzle. Explanatory drawing which shows the velocity distribution of the steel plate normal direction of the spreading angle (alpha) and a refrigerant | coolant jet. FIG. 9 is an explanatory plan view showing an example of interference (overlap) of a collision surface of a refrigerant jet between adjacent conical spray nozzles in the conveying direction, wherein (a) the overlap is half the diameter of the refrigerant collision surface; FIG. 4B shows a case where the overlap is 2/3 of the diameter of the refrigerant collision surface. Explanatory drawing which divided and showed the relationship between the maximum minimum ratio (-) of the cooling capability by a full cone spray nozzle, and the overlapping ratio of a refrigerant | coolant collision surface according to the jet spread angle of a full cone spray nozzle. (A) A figure is a plane explanatory view showing an example of arrangement of a full cone spray nozzle of a cooling device of a steel plate of the present invention, and (b) drawing is an explanatory view showing surface temperature distribution in the width direction of a steel plate after cooling. Plane explanatory drawing which shows the example of arrangement | positioning of the full cone spray nozzle as a comparative example with respect to this invention. Plane explanatory drawing which shows the other example of arrangement | positioning of the full cone spray nozzle as a comparative example with respect to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel plate cooling device 1a, 1b, 1c Nozzle row group 2 Hot finishing rolling mill 3 Steel plate 4a, 4b, 4c Restraining roll 5, 5 ₁ , 5 ₂ Conical spray nozzle placement 5a Refrigerant jet flow 6 Header pipe 7 On plate Refrigerant

Claims (4)

A cooling device having a plurality of constraining rolls for restraining and passing a metal plate, and a conical spray nozzle capable of controlling the amount of refrigerant injected between each pair of constraining rolls. In a vertical state, the metal plate is arranged in a plurality of rows in the width direction and the conveyance direction, and each full cone spray nozzle is arranged apart so that the collision surface of the injected refrigerant does not interfere with the metal plate surface, and When the refrigerant jet flow from each full cone spray nozzle is projected from the conveyance direction onto a vertical plane perpendicular to the conveyance direction of the metal plate, the refrigerant jet flow of the full cone spray nozzle adjacent in the conveyance direction of the metal plate is partially overlap the widthwise direction in a vertical plane and arranged so as to be projected, as the charge cone spray nozzle, of 5 to 40 degrees injector spread angle of the refrigerant charge cone Supurenozu Cooling system of the metal plate, characterized in that with. The overlap width of the refrigerant jet flow between adjacent conical spray nozzles in the conveying direction of the metal plate is not less than 0.4 times the bottom diameter of the refrigerant jet flow of both full cone spray nozzles on the vertical plane. The metal plate cooling device according to claim 1 . A plurality of nozzles so that the collision surface of the refrigerant jet flow from each full cone spray nozzle partially overlaps in the width direction of the projection vertical plane and covers the entire width of the metal plate in the unit between each constraining roll pair. The metal plate cooling device according to claim 1 , wherein a row is arranged. The cooling device for a metal plate according to any one of claims 1 to 3 , wherein the metal plate being transported is arranged to be cooled, the metal plate is cooled by a jet refrigerant from a full cone spray nozzle of the cooling device, and cooled. A method for cooling a metal plate, characterized by enhancing uniformity of the temperature distribution in the width direction of the subsequent metal plate.

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