JPH0238283B2 - KOHANREIKYAKUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steel plate cooling device that has good cooling efficiency and is uniform in cooling.

FIG. 1 is a diagram showing a conventional water jet cooling device for cooling a hot steel plate.

In FIG. 1, 1 is a hot steel plate, 2 is an upper slit-shaped nozzle, 2' is an upper header, 3 is a lower slit-shaped nozzle, 3' is a lower header, 4 is arranged in parallel in the same plane at a predetermined interval, This is a roll that forms a running track for hot steel plates.

The hot steel plate 1 is cooled by cooling water jetted from a group of slit-shaped nozzles via headers 2' and 3' while moving on a running path formed by the rolls 4.

The drawbacks of this conventional device will be described below.

Figure 2 is an enlarged view of the vicinity of the slit-shaped nozzle in Figure 1, Figure 2a is a longitudinal cross section in the direction of travel of the hot steel plate, and Figure 2b is a diagram showing the temperature change of the hot steel plate. , the vertical axis indicates the temperature of the heated steel plate, and the horizontal axis indicates the position of the heated steel plate in the advancing direction, and the position corresponds to FIG. 2a.

As shown in FIG. 2a, the slit-shaped nozzle 2
After the cooling water collides with the hot steel plate 1, it not only cools the vicinity of the collision part, but also flows over the top surface of the hot steel plate 1 and cools the hot steel plate 1 there as well. While the temperature drops as shown by the broken line, the cooling water from the slit nozzle 3 immediately falls away from the hot steel plate 1 after colliding with the hot steel plate 1, and locally cools only the area near the collision part. The lower layer of the hot steel plate 1 experiences a temperature drop as shown by the solid line in FIG. 2b, resulting in unbalanced cooling.

To deal with such a cooling imbalance, in the conventional apparatus, a method is adopted in which the ratio of the cooling water flow rates of the slit-shaped nozzles 2 and 3 is selected so that the average heat load is the same on the upper surface side and the lower surface side.

However, locally, non-uniform cooling as shown in FIG. 2b occurs repeatedly, resulting in non-uniform material quality and deformation.

In addition, in such conventional equipment, the amount of cooling water is adjusted so that the heat loads on the top and bottom surfaces, which have different cooling patterns as described above, are the same on average, so the cooling capacity of the top surface is effectively the same as that of the bottom surface. It is only used with the same local cooling capacity as the impinging jet alone. In other words, the upper flow rate is adjusted so that the amount of cooling by the lower impinging jet = cooling water by the upper impinging jet + the amount of cooling by water flowing on the upper surface after the collision, and in effect the upper surface of the heated steel plate is This means that the cooling capacity of the flowing water is not utilized. Furthermore, the flow of cooling water flowing over the hot steel plate varies depending on changes in conditions such as the speed of the hot steel plate, the width of the plate, the amount of cooling water, etc., and a complicated adjustment of the ratio of the upper and lower cooling water amounts is required.

Furthermore, as shown in Fig. 3, the cooling water from the slit-shaped nozzle 2 on the top surface of the hot steel plate flows on the top surface of the hot steel plate after colliding with the hot steel plate, but the cooling water interferes with the water flow from the adjacent slit-shaped nozzle, resulting in the width of the plate width. It flows in this direction and eventually falls off the edge of the board. Due to this water flow in the width direction of the plate, the cooling heat load due to water on the surface of the hot steel plate is not uniform, and the heat load near the edge of the plate becomes high.

This uneven cooling causes temperature distribution in the width direction of the hot steel plate, causing deformation of the plate and non-uniformity of the material.

The present invention is based on the knowledge that it is necessary to eliminate this uneven cooling in order to improve the quality of the steel sheet and increase the cooling capacity, and that it is sufficient to use the same cooling pattern on the top and bottom surfaces of the hot steel sheet. It has been done.

That is, in the present invention, a set of two slit-shaped nozzles are disposed facing each other on the upper and lower sides of a hot steel plate that is transferred on rolls arranged in the same plane at predetermined intervals, and the set of slit-shaped nozzles is The two slit-shaped nozzles forming the strip are inclined in directions facing each other, and a partition plate is provided between the tips of the two slit-shaped nozzles forming the one set, covering the entire length in the width direction of the strip. The present invention relates to a steel plate cooling device characterized by comprising:

In contrast to the conventional single slit nozzle, the device of the present invention consists of two slit nozzles forming a set of nozzles, and furthermore, the two slit nozzles are tilted in directions facing each other to cool the jet after ejection. Water is held between these two slit-shaped nozzles and discharged in the width direction of the plate.

The device of the present invention can be applied as a (thick plate) steel plate cooling device (water jet type).

FIGS. 4a and 4b are views showing an embodiment of the apparatus of the present invention, and FIG. 4b is a partially enlarged detailed view of FIG. 4a.

In FIGS. 4a and 4b, 1 is a hot steel plate, 2 is two slit-shaped nozzles inclined in directions facing each other with an angle α of 0° < α < 90° with respect to the upper surface of the hot steel plate 1; 2' is a header. Also, 3 is the hot steel plate 1
Two slit-shaped nozzles are similarly inclined with respect to the lower surface of the hot steel plate 1, 3' is a header, and 4 is a roll arranged in parallel on the same plane at a predetermined interval to form a running path for the hot steel plate 1. In addition, 5 and 6 are respectively heat steel plate 1
A strip is installed in the width direction of the hot steel plate 1 between the tips of two slit-shaped nozzles that are inclined in directions facing each other on the upper and lower sides (between the tips of 2 and 2 and between the tips of 3 and 3). This is a partition plate attached so as to close the space between the tip portions over the entire length. Note that 7 and 8 indicate cooling water jets ejected from the slit nozzles 2 and 3.

The heated steel plate 1 is cooled by cooling water jetted from slit-shaped nozzles 2 and 3 via headers 2' and 3' while being transferred by rolls 4 along a substantially horizontal running path.

Here, the cooling water becomes jets 7 and 8 and the hot steel plate 1
After the collision, the cooling water flows through the partition plate 5, two jets 7, and the upper side of the hot steel plate.
and the hot steel plate 1, and the lower side of the hot steel plate is held in the space consisting of the partition plate 6, two jets 8, and the hot steel plate 1. It flows towards the end and is discharged from the end.

Therefore, the two slit-shaped nozzles facing each other at an angle α form two jets facing each other, which cool the hot steel plate and remove the cooling water after colliding with the hot steel plate. The partition plate functions to prevent the cooling water from flowing out of the collision range, and the partition plate retains the cooling water after the collision near the hot steel plate, regulates the cooling water drainage passage, and fills the above space with the cooling water. effect.

According to the device of the present invention described in detail above, the following effects can be achieved.

(1) The cooling pattern on the top and bottom sides of the hot steel plate is the same.

If the amount of cooling water on the upper and lower sides is the same, the cooling due to the collision of the jets will be the same. In addition, the cooling water after collision on the top surface of the hot steel plate does not spread out of the jet range, and on the other hand, the cooling water on the bottom surface after the collision does not fall immediately. Since it is discharged in a space filled state, the cooling of the upper and lower surfaces is exactly the same.

(2) Cooling capacity is improved.

In conventional equipment, the average heat load on the top and bottom surfaces is the same, so the cooling capacity of the top surface is effectively
It is only used as much as the local cooling capacity of the lower impinging jet. In contrast, according to the device of the present invention, the cooling water after the collision fills the space on both the upper and lower surfaces, that is, the cooling water on both the upper and lower surfaces is discharged while contacting the hot steel plate, so this cooling capacity can also be utilized. .

(3) Operation becomes easier.

With conventional equipment, the cooling patterns for the top and bottom surfaces are different, making it necessary to change the cooling water ratio.
This is because the cooling water flows unregulated on the top surface of the steel plate after a collision, and the flow of cooling water on the top surface of the steel plate varies depending on conditions such as the speed of the hot steel plate, the width of the plate, the amount of cooling water, etc., and is complex. However, by providing the same cooling pattern on the upper and lower surfaces of the device of the present invention, this adjustment work is no longer necessary.

(4) Uneven cooling is eliminated.

In the device of the present invention, the partition plate regulates the cooling water channel after the collision, and the partition plate and the
Since the space formed by the book jet and the heated steel plate is filled with the cooling water, uneven cooling in the width direction of the heated steel plate, which was observed in conventional devices, is eliminated.

As described above, according to the device of the present invention, the drawbacks of the conventional device described above can be overcome.

In addition, a description will be added below of a preferable arrangement example of the partition plate that can more easily eliminate this drawback.

FIG. 5 is an enlarged cross-section of the upper slit-shaped nozzle portion of the apparatus of the present invention shown in FIG. In this slit-shaped nozzle, the partition plate 5 may be attached so that the distance X from the hot steel plate 1 is the minimum at the center in the width direction of the plate and the maximum at the ends as follows.

Ai=Ac+AoLi/Lo...(1) Here, Ao: Space area surrounded by the jet 7, partition plate 5, and hot steel plate 1 at the end of the slit-shaped nozzle in the plate width direction Ac: The above space area at the center in the plate width direction Lo: Plate Distance Ai from the center in the width direction to the end of the slit-shaped nozzle; Area of the space at any cross section i in the board width direction Li; Distance from the center in the board width direction to cross section i. In other words, this allows cooling water to flow filling the space. The flow velocity of the cooling water and the contact length between the cooling water and the heated steel plate are the same in the width direction of the plate, allowing for even more uniform cooling.

Note that it is also possible to keep the flow velocity the same by changing the slit-shaped nozzle distance l in the sheet width direction, but since the contact length between the cooling water and the hot steel sheet increases as it approaches the sheet edge, the cooling amount This causes an imbalance. However, the amount of cooling can be kept constant in the width direction by changing the combination of l and X.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a conventional water jet type hot steel plate cooling device, Fig. 2 is an enlarged view of the vicinity of the slit-shaped nozzle in Fig. 1, and Fig. 2a is a longitudinal cross-section in the direction of progress of the hot steel plate. Figure 2b is a diagram showing the temperature change of the hot steel plate, Figure 3 is a diagram for explaining the flow of cooling water on the hot steel plate in the case of the device shown in Figure 1, Figure 4a, b is a diagram showing an example of an embodiment of the device of the present invention, FIG. 4b is a partially enlarged detailed view of FIG. 4a, and FIG. It is a figure for explaining an aspect.

Claims (1)

[Claims] 1 Two pieces of hot steel plate are placed opposite each other on the top and bottom of the hot steel plate transferred on rolls arranged on the same plane at predetermined intervals.
A set of slit-like nozzles are arranged, and the two slit-like nozzles making up the set are inclined in directions facing each other, and a strip is arranged between the tips of the two slit-like nozzles making up the set. A steel plate cooling device comprising a partition plate that closes the space between the tips over the entire length in the width direction.