JPS6255922B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a metal material cooling device used in a cooling device for rolled material at the outlet of a rolling mill, a cooling device for heat treatment of metal, and the like. Traditionally, water cooling has been widely used to cool heated metal materials, including spray cooling equipment that sprays cooling water under pressure, laminar flow cooling equipment that flows water in a laminar flow over the top of the metal, and water cooling equipment that sprays cooling water under pressure. A spray cooling device using air was used. An example of this will be explained with reference to FIG. 1. A water stream b is flowed from a cooling water nozzle d to a metal material a to cool the metal material a. However, where the metal material a and the water flow b come into contact, the cooling water evaporates and a vapor film c is generated, and this vapor film c cannot be peeled off uniformly, so the heat transfer is reduced to 1/10 at the location where the vapor film c is present.
At the same time, the cooling rate decreased, uneven cooling occurred, and deformation of the metal material a also occurred. In order to improve such a decrease in the cooling rate and uneven cooling, attempts have been made to increase the pressure of the water stream b to, for example, about 10 Kgf/cm ² to peel off the steam film c. 50mm before and after the part that collides with a
It was only possible to remove the vapor film from a certain number of locations. Another improvement method was to increase the amount of water as much as possible and use a large amount of water flow b to peel off the steam film c, but this also required more than twice the theoretical amount of cooling water, and the water flow was also It was effective only up to about 50 to 100 mm from the part where b collides with metal material a. If the metal material a is deformed due to uneven cooling, the deformation of the metal material a will increase even more in equipment that does not have pressure rolls on the top and bottom or left and right sides of the metal material a, which may cause damage to the equipment. was. The present invention improves these conventional drawbacks and makes it possible to uniformly cool metal materials with a small amount of cooling water, and is suitable for use in a metal material cooling device that cools heated metal materials with water while continuously conveying them. , a cooling water nozzle equipped with an ultrasonic vibrator is provided in the initial cooling section where the surface temperature of the heated metal material is high, and an ultrasonic vibrator is provided in the cooling section on the exit side where the surface temperature of the heated metal material has decreased. The gist of the invention is a metal material cooling device characterized in that it is provided with a cooling water nozzle. Next, an embodiment of the present invention will be described with reference to FIG. 2. Reference numeral 1 is a metal material cooling device according to the present invention, in which a large number of upper rolls 2 and lower rolls 3 are each provided horizontally. 3 is adapted to be rotated by a roll drive device 4 as shown in FIG. For this reason, the metal material cooling device 1
The heated metal material 5 placed between the upper roll 2 and the lower roll 3 from the inlet side of the metal material cooling device 1 is continuously conveyed to the right in FIG. 2 toward the outlet side of the metal material cooling device 1. become. The upper roll 2 is supported by an elevating beam 6, and the elevating beam 6 is raised and lowered by the operation of an elevating cylinder 7 to match the thickness of the heated metal material 5.
The distance between the upper roll 2 and the lower roll 3 is set. An upper cooling water nozzle with a vibrator 8 is provided in the initial cooling section near the inlet side of the metal material cooling device 1, and an upper cooling water nozzle without a vibrator is provided in a location near the outlet side of the metal material cooling device 1. The upper cooling water nozzle 8 with a vibrator and the upper cooling water nozzle 9 without a vibrator are both supported by the lifting beam 6 so as to be located between the upper rolls 2, 2. There is. As shown in FIG.
2. Cooling water is supplied via the water flow control valve 13. Upper cooling water nozzle with vibrator 8
As shown in FIG. 5, there is a slit-shaped water outlet 14 below the slit-shaped water outlet 14.
extends in the width direction of the heating metal material 5. The above-mentioned cooling water supplied by the water supply pump 11 flows out from the water outlet 14 toward the surface of the heated metal material 5 as a cooling water flow 15. Water outlet 1 in upper cooling water nozzle 8 with vibrator
A plurality of ultrasonic transducers 16 are located directly above the fourth
The ultrasonic transducers 16 are installed as shown in FIGS. 5 and 5, and each ultrasonic transducer 16 is connected to a controller 18 via an ultrasonic oscillator 17, as shown in FIG. The upper cooling water nozzle 9 without a vibrator on the outlet side shown in FIG. There is only a slit-shaped water outlet that flows out towards the water. A lower cooling water nozzle with a vibrator 19 is provided in the initial cooling section near the inlet side below the heating metal material 5, and a vibrator or lower cooling water nozzle 20 is provided in a location near the outlet side. . The lower cooling water nozzle with a vibrator 19 is equipped with an ultrasonic vibrator 21 in the same way as the upper cooling water nozzle with a vibrator 8 described above, and these ultrasonic vibrators 21 are also connected to the controller 18. ing. No ultrasonic vibrator is attached to the lower cooling water nozzle 20 without a vibrator, and these lower cooling water nozzles 1 with a vibrator
9. Both of the vibrator-less lower cooling water nozzles 20 are configured to flow cooling water toward the back surface of the heated metal material 5 from a slit-shaped water outlet. The upper cooling water nozzle 8 with a vibrator and the lower cooling water nozzle 19 with a vibrator, which perform initial cooling of the heated metal material 5, are equipped with water seal covers 22 and 23 for putting the heated metal material 5 into the water flow. At the upper right end of the upper water seal cover 22 in FIG.
A discharge port 24 is formed to discharge the cooling water to the left and right (in the vertical direction in FIG. 2). In FIG. 2, the upper cooling water nozzle with a vibrator 8 and the lower cooling water nozzle with a vibrator 19, which are closest to the inlet side on the left side, are arranged with respect to the advancing direction of the heated metal material 5 in order to prevent backflow of water. The cooling water flow exits at an angle α of 10° to 40°. In the metal material cooling device described above, the cooling water supplied from the water supply pump 11 is supplied to the water flow control valve 13.
The amount of water is adjusted and enters the upper cooling water nozzle 8 with a vibrator and the lower cooling water nozzle 19 with a vibrator. Then, after being subjected to ultrasonic vibration by the ultrasonic vibrators 16 and 21, it flows out toward the heated metal material 5. The vapor film generated on the surface of the heated metal material 5 is continuously peeled off by the vibration energy of the cooling water. The ultrasonic vibration is applied to the heated metal material 5 by the controller 18.
The output is controlled in accordance with the shape and dimensions of the heated metal material 5, and the cooling of the heated metal material 5 is made uniform and the cooling rate is improved. The preferable range for ultrasonic waves is 15kHz to 500kHz from the viewpoint of noise prevention and output attenuation prevention, and the output of each ultrasonic vibrator 16, 21 is 10W to 500W.
Adjust to. The following table shows the cooling effect when an ultrasonic vibrator is attached to the cooling water nozzle.

【table】

[Table] The surface temperature of the heated metal material 5, which was initially cooled by the cooling water flow having ultrasonic vibration energy flowing out from the upper cooling water nozzle 8 with a vibrator and the lower cooling water nozzle 19 with a vibrator, was approximately 300°C. ℃ or below, the evaporation of the cooling water turns into nucleate boiling and no longer forms a vapor film, and this nucleate boiling action also has the effect of stirring the cooling water flow, so the cooling on the outlet side of the metal material cooling device 1 is as follows: This is uniformly and efficiently performed by the vibrator-less upper cooling water nozzle 9 and the vibrator-less lower cooling water nozzle 20, which are not provided with an ultrasonic vibrator. In the present invention, the vapor film generated on the surface of the heated metal material is continuously peeled off in the initial cooling section where the temperature is high, so the cooling rate is improved and uniform cooling can be performed, and the deformation of the heated metal material is small. This has the effect of improving the cooling rate. In addition, high water pressure is not required to remove the steam film, and the amount of water required is small, so the amount of cooling water and pump power costs are also reduced, and even on the exit side of the heated metal material, cooling water without ultrasonic vibration can be used. Furthermore, cooling can be performed more uniformly and effectively. Furthermore, when the heated metal material is a hardened material, improved cooling improves hardenability, which has the effect of significantly improving the quality of the coolant.

[Brief explanation of the drawing]

FIG. 1 is a vertical side view of a conventional cooling water nozzle, FIG. 2 is a side view of an embodiment of the present invention, and FIG. 3 is a side view of a conventional cooling water nozzle.
4 is a system diagram of piping and wiring for the cooling water nozzle with a vibrator, and FIG. 5 is a longitudinal sectional side view of the cooling water nozzle with a vibrator. 1... Metal material cooling device, 5... Heating metal material, 8
... Upper cooling water nozzle with vibrator, 9 ... Upper cooling water nozzle without vibrator, 16 ... Ultrasonic vibrator, 1
9...Lower cooling water nozzle with vibrator, 20...Lower cooling water nozzle without vibrator.

Claims (1)

[Claims] 1. In a metal material cooling device that cools a heated metal material with water while continuously conveying the heated metal material, a cooling water nozzle equipped with an ultrasonic vibrator is provided in an initial cooling section where the surface temperature of the heated metal material is high, and the heating metal material is cooled with water. A metal material cooling device characterized in that a cooling water nozzle without an ultrasonic vibrator is provided in a cooling part on the exit side where the surface temperature of the metal material has decreased.