JPS6268612A - Cooling method for rolling roll - Google Patents

Abstract

PURPOSE:To efficiently perform cooling rolls for rolling by specifying the speed of cooling water in a clearance of a cooling water jacket to which the roll cooling water is fed against a peripheral surface of the rolling roll and in the cooling water jacket. CONSTITUTION:The cooling water jacket 12 is constituted equipping feed water port and exhaust port 46, 48 communicating to a tooling water system 40 in the opposite part of the roll 13 opposing to the peripheral surface of the rolling roll 10. When the cooling of the roll 10 is performed by feeding the cooling water into the jacket 12, the clearance between the opposite part 13 for the roll and the peripheral surface of the roll 10 is regulated to 2-5mm and the speed of cooling water in the jacket 12 is 3-30m/s. In this way, the cooling of the rolling roll is efficiently performed.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for cooling a roll in a rolling mill, and in particular, a cooling water jacket is provided along the outer periphery of the rolling roll so that the cooling water comes into contact with the outer periphery of the rolling roll. , relates to an improvement in a method of cooling a mill roll during rolling by supplying roll cooling water into the cooling water jacket.

[Conventional technique #I]

In hot rolling, a large amount of heat flux is generated from the material to be rolled to the rolling rolls during rolling, resulting in rough skin due to thermal fatigue of the rolls and thermal expansion in the threaded portion of the rolls. In order to prevent surface flaws and poor flatness caused by these, it is necessary to cool the rolling rolls. Conventionally, mill rolls have been cooled by spraying cooling water onto the surface of the mill roll during rolling, and the sprayed cold water collides with the roll surface, where heat exchange occurs. This spray type cooling method is suitable for 10 to 30 kg
/ CD high pressure water is sprayed by a nozzle,
There is a problem in that the area where the cooling water contacts the rolls is limited, and even if the cooling main stream is increased, the cooling area remains unchanged, making it impossible to achieve a significant increase in the cooling effect. In addition, the cooling water that is sprayed and collides with the rolling roll ζ scatters and falls onto the material to be rolled, which lowers the rolling temperature, which wastes a lot of energy and makes it difficult to control the material quality of the material to be rolled. There was a problem with this. Furthermore, the cooling water after being sprayed onto the rolling rolls becomes hot water and falls into the sluice below the rolling mill, where it is collected together with descaling and other cooling water and oil after hydraulic rolling, and circulated through water treatment equipment. has been done. Therefore, it is impossible to control the temperature or improve the water quality of the roll cooling water alone, and for this reason, there are limits to improving the quality of rolled materials in terms of temperature control and water quality of the roll cooling water. . On the other hand, for example, as shown in Japanese Patent Publication No. 12322/1980, cooling efficiency is improved by installing a cooling water jacket along the surface of the rolling roll and supplying cooling water to this cooling water jacket. A so-called cooling water jacket type roll cooling power method has been proposed. In addition, as proposed in Japanese Utility Model Application No. 58-52752, a closed cycle is formed in which the cooling water supplied to the cooling water jacket is directly recovered, thereby reducing the amount of cooling water used and Some systems are designed to prevent cooling water from leaking onto the rolled material. (Problem to be solved by the invention 1) However, even in the case of the rolling roll cooling method using a closed cycle in which the cooling water supplied to the cooling water jacket is directly recovered as described above, it is difficult to obtain appropriate cooling water. There is a problem in that efficient cooling cannot be performed unless a gap is provided between the supply element, the cooling water jacket, and the rolling roll.The present invention was made in view of the above-mentioned conventional problems. It is an object of the present invention to provide a method for cooling a mill roll that can cool the mill roll with high efficiency using a cooling water jacket. This is based on the inventor's findings based on experiments, and a cooling water jacket is provided along the outer periphery of the rolling roll so that the cooling water comes into contact with the outer periphery of the rolling roll, and roll cooling water is poured into the cooling water jacket. In the method of cooling a rolling roll during rolling by supplying cooling water, the gap between the cooling water jacket and the outer circumferential surface of the rolling roll is set to 2.
5 u and the cooling water velocity within the cooling water jacket is 5 to 30 m/sec, thereby achieving the above object.

[Operation 1] In this invention, the gap between the rolling roll outer periphery and the cooling water jacket and the flow rate of the cooling water supplied to the cooling water jacket are set to optimum values based on experimental findings. Cooling is performed with high efficiency. [Example] The present invention will be explained in detail below with reference to the drawings showing an apparatus for carrying out the method according to the present invention. As shown in FIGS. 1 and 2, this device includes a cooling water jacket 12 provided along the outer periphery of the rolling roll 10 so that the cooling water comes into contact with the outer periphery of the rolling roll 10,
In the method of cooling the roll roll 10 during rolling by supplying roll cooling water into the cooling water jacket 12, a rectangular frame-shaped roll facing part 13 of the cooling water jacket 12 facing the outer peripheral surface of the roll roll 10 is provided. bottom surface 13
The gap t between A and the outer periphery of the rolling roll is 2 to 5 mm, and the cooling water velocity in the cooling water jacket 12 is v=
5 to 30 m/sea. At both ends of the roll facing portion 13 in the rolling roll axial direction,
A touch roll 14 that rolls into contact with the outer peripheral surface of the rolling roll 10,
Three labyrinth seals 16 are arranged at equal intervals in the circumferential direction so as to protrude from the bottom surface of the roll facing part 13, and labyrinth seals 16 are provided on the entire periphery of the roll facing part 13 of the cooling water jacket 12.
is formed. The cooling water jacket 12 including the touch roll 14 is urged toward the outer circumferential surface of the rolling mill 10 by a pushing rock structure 18 (whole not shown). Reference numeral 40 in the figure indicates a cooling water system for circulating and supplying cooling water into the cooling water jacket 12, and this cooling water system 40
is equipped with a pump 42 and a heat exchanger 44, and is connected to a water supply 046 and a drain port 48 formed within the cooling water jacket 12. Reference numeral 50 indicates a backup roll that rotates in contact with the rolling roll 1o from above and below to regulate the position of the rolling roll 10, and 52 indicates a guide for smoothly inserting and extracting the rolled material A into the rolling roll 10. In this embodiment, when cooling water is circulated and supplied from the cooling water system 40 into the cooling water jacket 12 during rotation of the rolling roll 10, the labyrinth seal 16 close to the outer peripheral surface of the rolling roll 10 connects the cooling water jacket 12 to the rolling surface. The rolls 10 are sealed and a cooling water passage is formed along the outer peripheral surface of the roll 10, and the roll 10 is cooled by the cooling water circulating inside the cooling water jacket 12 at a speed of v=5 to 3 Qm/sea. will be cooled. Here, the gap t between the outer peripheral surface of the rolling roll 10 and the bottom surface 13A of the roll facing portion 13 of the cooling water jacket 12 is always kept constant at 2 to 5 degrees by the touch roll 14. Said V=5~30m/sea and t=2~5mm
The numerical value was obtained as a result of the inventor's experiment. That is, as shown in FIG. 3, the gap between the surface of the rolling roll 10 and the bottom surface 13A of the roll facing portion 13 = 2
3 nm, 5. The relationship between the flow fiQ of the cooling water supplied to the gap and the heat transfer coefficient α on the surface of the rolling roll 10 when the gap t is smaller and the flow ff1Q is larger is the heat transfer. It turns out that the rate α is large. Here, compared to the case of the conventional one-spray cooling method shown by the broken line in FIG. It can be seen that the cooling efficiency of the jacket type cooling method is higher than that of the one-spray type cooling method shown by the broken line in FIG. This Q=100m'/h-m is V when t=5mm(7)
= 5m/sec. Also, when t=2u, as can be seen from Figure 3,
The cooling capacity is saturated at Q=200+n3/h -m. At this time, the flow rate of the cooling water corresponding to Q=200 m'/hm is V=30 m/sec. Furthermore, if the gap t is smaller than 2m, an improvement in the cooling capacity per m of cooling water can be expected, but if the gap i<2m
It becomes difficult to implement mechanical optimization to maintain m, and the pressure loss becomes large, and the pressure of the cooling water to be supplied must be increased, making it impossible to reduce the power source unit. Can not. Therefore, the appropriate gap t is 21111 or more. Therefore, the proper values for the gap t are 2 to 5 meters, and the flow rate v of the cooling water supplied to the gap is 5 to 3 Qm/sec. In the above embodiment, three touch rolls 14 are arranged at equal intervals in the circumferential direction on both ends of the roll facing portion 13 of the cooling water jacket 12 in the direction of the rolling roll 1111. However, the number δ1 of the touch rolls 14 may be decreased or increased depending on the diameter of the rolling roll 10. Furthermore, a gap t between the bottom surface 13A of the roll facing portion 13 in the cooling water jacket 12 and the outer peripheral surface of the rolling roll 10
The structure for maintaining the gap t of 2 to 5n is not limited to the touch roll 14 as in the above embodiment, and is not limited to the above embodiment as long as it can maintain the gap t appropriately. Further, as a means for bringing the cooling water jacket 12 into contact with the outer circumferential surface of the rolling roll 10 to form a closed cycle, a frame-shaped labyrinth seal 16 is provided on the roll facing portion 13.
However, if other sealing means are provided, the structure is not limited to the above embodiment. [Effects of the Invention] Since the present invention is configured as described above, it has an excellent effect in that the rolling roll can be cooled with high efficiency using the cooling water jacket.

[Brief explanation of drawings]

Fig. 1 is an overall side view, not showing the equipment for carrying out the cooling fij method for rolling rolls according to the present invention, Fig. 2 is an enlarged sectional view showing the main parts of the equipment, and Fig. 3 is a cooling water A diagram showing the flow rate and cooling capacity in relation to the gap between the cooling water jacket and the rolling roll, Figure 4 shows the cooling efficiency and cooling water flow rate,
FIG. 3 is a diagram showing the relationship between a cooling water jacket and a gap between a rolling roll. DESCRIPTION OF SYMBOLS 10... Rolling roll, 12... Cooling water jacket, 1.3... Roll opposing part, t... Gap, ■... Flow rate.

Claims (1)

[Claims] (1) A cooling water jacket is provided along the outer periphery of the rolling roll so that the cooling water comes into contact with the outer periphery of the rolling roll, and by supplying roll cooling water into the cooling water jacket, the rolling roll is cooled during rolling. In the cooling method, the gap between the cooling water jacket and the outer peripheral surface of the rolling roll is set to 2.
5 mm and a cooling water velocity within the cooling water jacket of 5 to 30 m/sec.