JPH0318408A - Cooling device for rolling roll - Google Patents

Abstract

PURPOSE:To efficiently cool rolling rolls and to cool without the change of cooling capacity even if the diameter is changed due to roll grinding, etc., by sealing cooling water by abuting a water-cooled jacket on water feeding and drain passages and the rolling rolls and injecting plural pressurized water on the opposed face of the rolling rolls. CONSTITUTION:When the rolling rolls 10 are cooled with a cooling devices 1, cooling water 11 is fed from the water feeding passages 5 for cooling water. Cooling water 1 is drained off from the drain passages 6 for cooling water after cooling the rolls 10 through the passage 4 for cooling water which is formed of the surface of rolling roll and inside surface of the water-cooled jacket. At that time, because boundary layer 12 where heat transfer is obstructed is produced on the surface of the rolling rolls, pressurized water 13 is injected from injection nozzles 7 there. Thereby, the boundary layer 12 which is produced on the surface of the rolls is broken with pressurized water 13. As that result, it is possible that the rolling rolls 10 and cooling water 11 are brought into direct contact with each other and cooling effect can be considerably improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a cooling device for rolling rolls, and more specifically, a cooling device for rolling rolls that can be efficiently cooled with the same equipment even when the diameter of the rolling rolls changes, and in which the cooling capacity remains unchanged. Regarding the equipment. (Prior Art) Rolling rolls used for hot rolling steel plates expand, wear out, and become rough due to the large amount of heat received from the material to be rolled. Therefore, in order to prevent these problems as much as possible, the rolling rolls are cooled with cooling water. Conventional methods and equipment for cooling rolling rolls include the following. a. A method in which a large amount of high-pressure cooling water is injected from a nozzle onto the roll surface. With this method, the cooling water scatters after hitting the rolls, so only a small area can be cooled. Moreover, only the part where the cooling water is injected is supercooled, so it is not cooled uniformly. Furthermore, there is a problem in that the scattered cooling water falls onto the rolled material, causing a local temperature drop and disrupting temperature control. b. As shown in FIG. 4(a), water cooling jackets 2 are disposed opposite to each other on the outer circumferential surface of the rolling roll 10 to form a cooling water passage 4, through which cooling water l1 is passed to increase the cooling area and to achieve uniform cooling. Equipment (Special Publication 55-12
Publication No. 322). This cooling device solves the problem that occurs with the cooling water injection method described in a above. However, in this device, (in Fig. 4)
As shown in the enlarged view of part A in FIG. 4(a), a boundary layer 12 exists on the surface of the rolling roll 10 that prevents direct contact between the cooling water 11 and the roll IO. This has the disadvantage that cooling efficiency cannot be improved. In addition, in FIG. 4(a),
5 is a cooling water supply channel, and 6 is a cooling water drainage channel. C. A cooling device (Japanese Unexamined Patent Publication No. 60-231
510 Publication). As shown in Fig. 5, this device has protrusions 9 on the inner surface of the water cooling jacket 2.The distance between the tip of the protrusions 9 and the surface of the roll 10 is narrowed, and the amount of cooling water is increased to increase the flow rate. The boundary layer l2 cannot be broken unless the temperature is increased and strong turbulence is generated. There is also the problem that when a roll is ground and its diameter becomes smaller due to wear or surface roughness, the distance between the roll surface and the tip of the protrusion changes, which changes the cooling capacity. (Problems to be Solved by the Invention) The object of the present invention is to develop a rolling roll that can efficiently cool a rolling roll without changing its cooling capacity even if its diameter changes due to roll grinding or the like. The purpose is to provide cooling equipment. (Means for solving the problem) Rolls used in hot rolling receive heat from the material being rolled, causing them to expand, wear out, and become rough. As a result, the diameter of the roll changes in the width direction, causing elongation in the rolled product, making it difficult to control the shape and thickness appropriately. Therefore, the inventors of the present invention have completed various studies on a roll cooling device that can cool the rolls during rolling with high efficiency and that does not change the cooling capacity even if the roll diameter changes, and as a result, they have completed this invention. That is, the gist of the present invention is ``a cooling device for a rolling roll that cools the roll by forming a cooling water passage between the outer peripheral surface of the rolling roll and the inner surface of a water-cooling jacket, wherein the water-cooling jacket has a cooling water supply passage and an inner surface of a water-cooling jacket. 1. A cooling device for a rolling roll, comprising sealing means for sealing cooling water by contacting the rolling roll, and a plurality of pressurized water injection nozzles on a surface facing the rolling roll.

(Function) Hereinafter, the rolling roll cooling device according to the present invention will be explained with reference to the drawings.

FIG. 1 is a cross-sectional view of the roll cooling device 1 of the present invention in the roll axis direction. As shown in the figure, this cooling device 1 includes a rolling roll l.
It is placed so that it touches O. This cooling device 1 includes a water-cooling jacket 2 that forms a cooling water passage 4 between the cooling water jacket 2 and the roll outer peripheral surface when the cooling device 1 is placed in contact with the rolling roll IO, and a seal attached to the tip of the jacket 2 on the roll side. It is constructed from means 3. The water-cooled medium jacket 2 has a cooling water supply channel 5 in its lower part and a cooling water drainage channel 6 in its upper part, and has a plurality of pressurized water injection nozzles 7 on its surface facing the rolling rolls to which pressure water is supplied. A pressure water supply channel 8 is provided. For example, a small-diameter seal roll is used as the sealing means 3, thereby preventing leakage of cooling water. When cooling the rolling roll lO with such a cooling device t1, the cooling water 1 is supplied from the cooling water supply channel 5.
1 (low-pressure water with a pressure of about 2 to 3 kg 7 cm) is supplied. Cooling water 11 passes through a cooling water passage 4 formed by the rolling roll surface and the inner surface of the water cooling jacket, cools the roll 10, and then drains the cooling water. Water is discharged from the channel 6. At this time, a boundary layer 12 (see FIG. 4(b)) that inhibits heat transfer is formed on the surface of the rolling roll 10, so the injection nozzle 7 is
Pressure water 13 (high pressure water with a pressure of about 5 to 10 kg/cm") is injected from the roll. Then, as shown in FIG. 2, the boundary layer 12 generated on the roll surface is broken down by the pressure water 13. As a result, It becomes possible to bring the rolling roll 10 into direct contact with the cooling water 1 liter, and the cooling efficiency can be significantly improved.Furthermore, by adjusting the flow rate of the pressure water 13 according to the temperature of the rolling roll 10, the cooling capacity can be adjusted freely. For example, the roll temperature is low immediately after the rolls are reassembled, so cooling is performed only with cooling water without injecting pressure water, and as the roll temperature rises, the amount of pressure water is increased. Effective cooling can be achieved by reducing the amount of pressurized water when there is no material to be rolled, and increasing the amount of pressure water only when there is material to be rolled.In addition, this cooling device uses pressure water jet from the nozzle to cool the boundary layer. Since it can be easily destroyed, it has the advantage that the amount of cooling water required is less than that of conventional cooling systems.Furthermore, with this cooling system, even if the roll diameter changes, the cooling capacity can be cooled without changing.For example, in the case of a new roll. In this case, the cooling water passage 4 formed by the outer peripheral surface of the roll 10 and the inner surface of the water cooling jacket 2 becomes wider as shown in FIG. 3(a), but in such a case, the amount of pressure water is increased. In the case of a small diameter roll just before, the cooling water passage 4 becomes narrow as shown in Fig. 2(b), but in that case, the amount of pressure water is reduced.Even if the rolling roll diameter changes in this way, By increasing or decreasing the amount of pressurized water, cooling can be performed with the same cooling device without changing the cooling capacity. (Example) The cooling device of the present invention will be explained below with reference to Examples.First
The cooling water system of the present invention as shown in the figure was attached to a new work roll of a hot rolling mill, and the roll was used until it was scrapped, and the cooling status during that time was investigated. The diameter of the roll when new was 770mm, and the diameter of the roll just before disposal was 674mm.
-, cooling water passage (first
The gap 4) shown in the figure was 24m- and 5lIIIl. And the pressure in this cooling device is 2.4 kg/c++"
3.6 ml of cooling water was supplied per minute. The cooling water velocity in the cooling water passage was 0.60 m/sec when the roll was new and 3 m/sec before it was disposed of. Then, as the roll temperature rises, pressure water with a pressure of 7 kg/am" is applied from 0.6 to
Cooling water was injected from the nozzle into the cooling water passage at a rate of 1 m3/sin to cool the roll while destroying the boundary layer that formed on the roll surface. As a result, the following was revealed. In other words, ■ The same cooling device can efficiently cool everything from new rolls to rolls that are about to be disposed of, and the cooling capacity remains the same. ■ The cooling capacity is as good as the injection method, but the amount of cooling water is only about half that of the injection method.

■ Since the cooling water does not scatter as in the injection method, the temperature of the rolled material does not drop and temperature unevenness is eliminated, making it easier to control the temperature during rolling. ■ Although it is necessary to install an additional pressure water pump, the pressure and volume of cooling water can be reduced, reducing pump power consumption. (Effects of the Invention) As explained above, according to the rolling roll cooling water device of the present invention, it is possible to cool everything from new rolls to rolls that are about to be disposed of without replacing them, and in addition, the cooling efficiency is high and the cooling capacity is high. does not change. As a result, roll consumption and productivity are significantly improved, and high-quality steel sheets can be manufactured.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the rolling roll cooling device of the present invention in the roll axis direction, Fig. 2 is a diagram showing a state in which the boundary layer is destroyed by pressure water injected from a nozzle, and Fig. 3 (a) is , Figure 3 (b) is a diagram showing the cooling device of the present invention placed on a new roll, Figure 3 (b) is a diagram showing the cooling device of the present invention rearranged on a roll just before being disposed of, and Figure 4 (a) is a diagram showing a conventional water cooling jacket. A sectional view of the mold cooling device in the roll axis direction, Fig. 4 (6) is an enlarged view of part A in Fig. 4 (a), and Fig. 5 is
This is a diagram showing how the boundary layer is destroyed by turbulent flow generated by protrusions on the inner surface of the water cooling jacket. 1 is a cooling device, 2 is a water cooling jacket, 3 is a sealing means,
4 is a cooling water passage, 5 is a cooling water supply channel, 6 is a cooling water drainage channel, 7 is a pressure water injection nozzle, 8 is a pressure water supply channel, 9 is a protrusion, 10 is a rolling roll, 11 is a cooling water, 12 is a boundary layer, 1
3 is pressure water.

Claims (1)

[Claims] A cooling device for a rolling roll that cools the roll by forming a cooling water passage between the outer circumferential surface of the rolling roll and the inner surface of the water-cooling jacket, wherein the water-cooling jacket contacts a cooling water supply channel and the rolling roll to supply cooling water. 1. A cooling device for a rolling roll, comprising sealing means for sealing, and a plurality of pressurized water injection nozzles on a surface facing the rolling roll.