JPS5886904A - Quick cooler for steel plate in hot rolling installation for thick plate - Google Patents

Abstract

PURPOSE:To permit uniform quick cooling of a steel plate by injecting water flow from slit-like water supply nozzles onto the top and bottom surfaces of the hot steel plate passing through a traveling route over the entire width thereof and flowing the water. CONSTITUTION:A hot steel plate 1 right after rolling in a hot rolling installation for thick plates is passed in the traveling route between conveying rolls 2a, 2b and 2'a, 2'b at a prescribed speed in an arrow A direction. In this time, cooling water is injected from water feed nozzles 5, 5' onto the top and bottom surfaces of the plate 1 into upper and lower cooling water chambers 4, 4' across the entire width thereof, whereby the steel plate is cooled quickly. Then, injected cooling water is guided by upper, lower covers 3, 3', and flows only in the conveying direction and the opposite direction thereof without flowing in the transverse direction; therefore the plate 1 is cooled quickly uniformly. The cooling water is allowed to overflow onto the top surface of covers 3 by means of the partition plates 7 provided in the arc-shaped end parts 8 of the covers 3 and upper rolls 2a, 2b, whereby the formation of the cooling water flow in the transverse direction of the plate 1 is obviated and the one-sided cooling of the plate 1 is prevented.

Description

[Detailed Description of the Invention] In recent years, there has been an increasing demand for high-strength, fracture-tough thick steel plates suitable for welding across a wide range of products such as large-diameter welded pipes, ships, bridges, and offshore platforms. There is. In order to meet this requirement, the thick plate Shosagi facility also uses tempering after controlled rolling to control the rolling process and:
Recently, off-line rapid cooling technology for steel sheets has been developed for the purpose of toughening without heat treatment through direct quenching.

Conventionally, forced cooling of hot steel plates in hot plate rolling equipment was
The hairpin type laminar flow type shown in Fig. 1(a) is widely used in IJ tube cooling equipment.
Examples include the one-sided spray cooling system used for normalizing as shown in Figure 1(c), and the one-sided slit-type laminar flow cooling system shown in Figure 1(b), which has recently been put into practical use. All of them have limited cooling capacity, and it is difficult to apply heat treatment technology to take advantage of rapid cooling or wide-range cooling capacity control to fully achieve the above objectives.Also,
Compared to thin steel plates, it is especially important for thick steel plates to cool uniformly on the sheet metal surface to obtain homogeneous properties.
Uniform cooling cannot be expected much with these methods.

The one shown in Figure 1(d) is a forced circulation type cooling device that enables rapid cooling of thick steel plates by forming a high-speed flow of cooling water over the hot steel plate to be cooled. There are many problems such as gender issues, huge equipment costs, and difficulty in temperature control.

Currently, there is a growing need for high strength and toughness of thick steel plates, and there is an urgent need in the industry to develop online rapid cooling equipment for hot plate rolling equipment that can meet these needs.

The present invention was proposed for the purpose of providing an online rapid cooling device for hot plate rolling equipment that can meet the needs of such industry, and includes a hot steel plate running on a conveyor line after rolling, A cooling water chamber is formed between the camera and the camera surrounding it, and a jet water stream is applied to the hot steel plate under water in the cooling water chamber.
By creating a high-speed water flow on the hot steel plate, it is possible to rapidly cool the hot steel plate, and the cooling water is designed to generate a slit-shaped water flow that is uniform in the width direction, and to prevent the generation of a discharge flow in the width direction on the hot steel plate. This relates to a steel sheet rapid cooling device characterized by having a uniform cooling ability due to the structure of recovering the steel sheet.

Hereinafter, one aspect of the present invention will be specifically explained with reference to the embodiments shown in FIGS. 2 and 3. In those figures, 2as 2'
s is a pair of upper and lower conveyance rollers 2bt' disposed perpendicularly to the conveyance direction on the conveyance line of the hot steel plate 1 after hot rolling with the rolling rolls of the hot thick plate rolling equipment;
;t'b is the conveyance roller 2as 2/a
On the downstream side, a pair of upper and lower conveying rollers are arranged in parallel with the rollers 2a and 2'B at an appropriate distance, and the hot steel plate 1 is conveyed by the conveying rollers 2as 2/a.
, 2b and 2'b, it is conveyed in the direction of arrow A at a predetermined speed. Note that the lower rollers 2'a + 2'b of these transport rollers 2al, 2', 2b, and 2'b are supported by a fixed bearing (not shown) K, and the upper roller 2a is supported by a fixed bearing (not shown). , 2b
is rotatably supported by a jack-up type bearing (not shown) so as to be able to cope with changes in the thickness of the hot steel plate 1 being passed through. 6 is the upper row 22. It is an upper cover disposed above the sheet passing path between a and 2b over almost the entire width thereof, and the upper cover 3 is formed so as to surround the top and both sides of the sheet passing path, and the inside The trap is such that an upper cooling water chamber 4 is formed between the upper surface of the heated steel plate 1 passing through the plate threading path and the upper surface of the heated steel plate 1. Further, the upper cover 6 is appropriately inclined so that the distance from the hot steel plate 1 passing through the plate passage becomes narrower as it approaches the rain upper roller 2ay2b side from the central part. 5 is a slit-shaped water supply nozzle that spans the entire width of the central portion of the upper cover 6 and is connected at one end;
The other end is connected to a cooling water supply source (not shown). During operation of the device, cooling water from the cooling water supply source is injected into the cooling water chamber 4 through the water supply nozzle 5, collides with the hot steel plate 1 passing through the sheet passing path, and rapidly cools it. It's becoming a trap. In this case, the cooling water W from the water supply nozzle 5
The hot steel plate 1 is guided by the upper cover 3 and flows in the passing direction and the opposite direction as shown by the arrows in Fig. 3 while cooling the hot steel plate 1, but the upper cover 3 is inclined as shown in the figure. Since the flow path of the cooling water gradually becomes narrower, the cooling water is accelerated here, forms a high-speed jet water flow, and has a large cooling effect on the hot steel plate 1. The water that has cooled the hot steel plate 1 in this way is transferred to the upper roller 2 of the upper camera 3.
a
As shown in FIG. 3, it is reversed, overflows onto the upper camera 3, forms a discharge flow path 9 as shown in FIG.

In addition, 7 is a partition plate attached to both sides of the arcuate end 8 at both ends of the upper cover 3, and the partition plate 7 is attached to the upper roller 2as.
Together with 2b, it serves to regulate the flow of the cooling water in the width direction.

6' is a lower cover disposed between the lower rollers 2'a s 2'b, facing the upper cover 3 similarly to the upper cover 3, and is connected to the lower cover 3' and the sheet passing path. A lower cooling water chamber 4 similar to the upper cooling water chamber 4 is provided between the hot steel plate 1 and the hot steel plate 1.
' is formed. Reference numeral 5' denotes a slit-shaped water supply nozzle for supplying cooling water to the lower cooling water chamber 4', and the water supply nozzle 5', like the water supply nozzle 5 described above, is connected to a cooling water supply source (not shown). During operation of the apparatus, cooling water is injected and supplied to the lower cooling water chamber 4'JP3.

In this case, as in the case of the upper cooling water chamber 4, a high-speed jet flow is generated also in the lower cooling water chamber 4', giving a large cooling effect to the hot steel plate 1.

One embodiment of the apparatus of the present invention is configured as described above, and when the operation of the apparatus is started, the hot steel plate 1 immediately after being rolled in the hot plate rolling equipment is transferred to the upper and lower conveyors installed on the conveyor line. When the sheet is passed continuously in the direction of arrow A at a predetermined speed along the sheet passing path between the rollers 2a+2b and 2'a and 2'b, the upper and lower surfaces of the heated steel sheet are exposed to the upper and lower water supply nozzles 5 and 5'. After being rapidly cooled by the cooling water injected into the cooling water chambers 4, 4' over the entire width thereof, the cooling water is sent to the outside. In this case, the cooling water injected from the upper and lower slit-shaped water supply nozzles 5, 5' into the upper and lower cooling water chambers 4, 4' over their entire width is guided and transported by the upper and lower covers 3, 3'.
Since it flows only in the feeding direction and the opposite direction, and not in the width direction, the hot steel plate 1 is uniformly and rapidly cooled.

In addition, a partition plate 7 is provided at the arc-shaped end 8 of the upper cover 3, and the flow of cooling water in the width direction is regulated by the partition plate 7 and the upper rollers 2m and 2bK. Since the cooling water is allowed to overflow on the upper surface of the upper cover 6 as a weir, no flow of cooling water in the width direction occurs on the upper surface of the hot steel plate 1, thus preventing one-sided cooling of the hot steel plate 1 and reducing the flow in the width direction. This enables uniform cooling. As shown in the illustrated example, if the upper and lower covers 6°6' are sloped and the cooling water flow paths of the upper and lower cooling water chambers 4, 4' are sequentially narrowed, high-speed jets of cooling water will be generated on both the upper and lower surfaces of the hot steel plate 1. A flow is formed, which has the advantage of providing a greater rapid cooling effect to the hot steel plate 1.

In addition, the width of the upper and lower covers 6 and 6' of this cooling device is determined according to the maximum width of the rolled hot steel plate 1, but when cooling hot steel with a narrow width, it is necessary to In order to prevent one-sided cooling of the edges, it is necessary to install guides 10 that restrict the width direction of the upper and lower cooling water chambers. The cooling width can be controlled by making the emotional water supply sources to the upper and lower cooling water chambers 4, 4' divided by the guide 10 independent of each other.

By extending the guide J10 to the arcuate ends 8 of the upper and lower covers 6.3', it is possible to prevent the cooling water from flowing out in the width direction as described above. Furthermore, by finely adjusting the amount of cooling water supplied to the upper and lower cooling water chambers 4, 4', it is also possible to control the cooling efficiency in the width direction.

As described above, the upper and lower cooling water is surrounded by the upper and lower covers 3.3' and is formed between the upper and lower conveyance rollers 2a+2'a and 2b, 2'b arranged on the conveyance line. The chambers 4 and 4' constitute a cooling zone on the conveyance line, and serve to directly rapidly cool the hot steel plate 1 immediately after rolling. These cooling zones are provided by transport rollers 2a, 2'a.
2b and 2'b are used for draining, and a completely independent small cooling area is also formed. The length of the zone can be adjusted as appropriate. In addition, by appropriately controlling the pressure and flow rate of cooling water supplied to the cooling zone and the distance between the hot steel plate 1 and the inner surface of the upper and lower covers 3°3', the heat from the slit-shaped water supply nozzle 5.5' can be reduced. steel plate 1
It is also possible to provide cooling capacity pressure controllability by changing the cooling water jet pressure on the hot steel surface and the water flow velocity on the hot steel surface.

Since the apparatus of the present invention has the above-described configuration and operation, according to the present invention, the hot steel plate 1 passing through the plate threading path
Jet water streams from slit-shaped water supply nozzles 5 and 5' are sprayed across the entire width of the top and bottom surfaces of the cooling system, which provides uniform high cooling capacity in the width direction, making it possible to meet the needs of the industry. The practical effect of this method is that it is possible to realize an on-line rapid cooling device in a hot rolling facility.

Next, another embodiment of the present invention shown in FIG.
Two sets of upper and lower covers 6, 6' and cooling water chambers 4, 4/ are arranged above and below the sheet passage path between 2'b, and between the ends of the two adjacent sets of upper and lower covers. The difference is that a partition plate 13 is provided above the contact point 11, and a lower conveyance roller 14 is provided below. In the case of this example, the hot steel plate 1 is rapidly cooled while passing through two sets of cooling water chambers and sent out to the outside, and the same functions and effects as in the above-mentioned example are achieved.

Next, in still another embodiment of the present invention shown in FIG. The rollers 2a* 2'a, 2b, and 2'b are configured to flow toward only one side to form a high-speed water flow along both sides of the hot steel plate 1 for rapid cooling, similar to the above embodiment. It is something that has action and effect. In this example, a cooling water chamber 16.16' is located at a position opposite to the cooling water discharge direction.
In this example, conveyor rollers 2a, 2'a and 2b, 2'b are provided, and are filled with cooling water.
If the distance between the
This is effective when there is an obstacle such as a frame on the conveyor line structure between 2'b.

[Brief explanation of drawings]

Figures 1 (a), (b), (c), and (d) are schematic explanatory diagrams of a strong cooling system for hot steel plates in conventional hot plate rolling equipment, Figures 2 and 3, respectively. The figures are schematic explanatory diagrams of one embodiment of the present invention, in which Fig. 2 is a perspective view, Fig. 3 is a longitudinal sectional view,
FIG. 4 and FIG. 5 respectively show the third embodiment of the present invention.
It is a longitudinal cross-sectional view corresponding to the figure. In Figures 2 to 5, 1: Heat steel plate, 2a, 2b: Upper conveyance roller, 2
/a, 2'b: Lower conveyance roller, 3, 3/* Upper and lower covers, 4, 47 @ Upper and lower cooling water chambers, 5: Water supply nozzle, 7: Partition plate, 8: Arc-shaped end of upper and lower covers Part, 10
Nigaite 9゜

Claims (1)

[Claims] Two pairs of upper and lower conveyance rollers are arranged at appropriate intervals along the conveyance direction on the conveyance line of the hot steel plate, and one roller is placed between each upper roller and each lower roller of the two sets. Upper and lower cooling zones are formed by a hot steel plate passing over the conveyance line and upper and lower covers, and slit-shaped water supply nozzles are attached to the upper and lower covers of the cooling zones, respectively, over the entire width of the cooling zones. A rapid cooling device for a steel plate in a hot plate rolling facility, characterized in that the device is configured to inject cooling water into upper and lower cooling zones from a water supply nozzle.