JPH0191903A - Device for cooling work roll of hot rolling mill - Google Patents

Abstract

PURPOSE:To effectively cool work rolls by installing mist spray nozzles on both roll end parts of a face of top members fixed to outlet side upper and lower guides oppositing to upper and lower rolls and installing fluid nozzles in the central part. CONSTITUTION:Mist spray nozzles 18, 27 cooling roll surfaces at an immediately behind the roll biting part are installed on both roll end parts in the roll width direction of respective faces of top members 13, 22 of upper and lower guides guiding a rolled stock oppositing to upper and lower rolls. Fluid nozzles 18', 27' are also installed in the central part. Mists and fluid are injected onto roll surfaces on the outlet side of the roll biting part from respective nozzles to cool the surfaces. Hence, a temp. drop of a rolled stock is minimized to effectively cool the work rolls and to reduce used air volume.

Description

DETAILED DESCRIPTION OF THE INVENTION <Object of the Invention> Industrial Application Field The present invention relates to a work roll cooling device for a hot rolling mill, and more specifically, a hot rolling mill that cools the upper and lower work roll surfaces immediately after hot rolling. This relates to the machine's workpiece cooling system.

BACKGROUND TECHNOLOGY As shown in FIG. 9, the roll cooling means currently in common use involves rolling a rolled material 3 by passing it between an upper roll 1 and a lower roll 2. Upper and lower guides 4.5 are each supported by rotating shafts 6.1 on the exit side of .2,
A cooling header 8.9 is installed on the roll exit side of the upper and lower guides 4.5 for cooling. When cooling, since the cooling effect is greater when the cooling start point is placed closer to the roll bite portion, the cooling start point is placed near the scraper 10 as in the case of upper roll cooling, and the cooling range is set as wide as possible.

However, since the section of angle α (approximately 40° culm degree) from the exit side of the roll bit part to the scraper is an air cooling region, there is a limit to the amount of roll temperature cooling.

Furthermore, in Japanese Patent Application Laid-Open No. 57-103718, a two-stage draining device is installed on the exit side of the roll bite, and cooling water is sprayed onto the roll surface from above the core and between the descending drain plates, thereby achieving the same starting point for cooling the roll. A method of approaching the roll bite exit point is disclosed.

However, by installing an auxiliary header near the roll bite,
In practice, providing a second drain plate or the like for cooling is a cumbersome technique.

In addition, as described above, installing a cooling nozzle on the exit guide of a rolling mill to cool the surface of the work roll immediately after rolling is very effective for cooling the work roll, but on the other hand, the cooling water is There is a problem in that the material is also cooled, which has a negative effect on ensuring the temperature of the rolled material (particularly in the case of thin material).

Problems to be Solved by the Invention The present invention aims to solve these problems. Specifically, by combining cooling by mist spray and cooling by water flow, it is possible to effectively and economically cool work rolls. It is an object of the present invention to provide a work roll cooling device for a hot rolling mill.

<Structure of the Invention> Means for Solving the Problems and Their Effects The present invention provides a means for solving the problem and its operation. A mist spray nozzle is installed in the
It is characterized by a single-fluid nozzle provided in the center.

Hereinafter, the effects of the structure of the present invention will be explained with reference to the drawings.

FIG. 1 (at) is a longitudinal sectional view of an example of the cooling device according to the present invention, FIG. 1(b) is an enlarged front view of the nozzle part, and FIG. FIG. 3 is a graph showing the relationship between cooling water and friend heat m. FIG. 4 is a graph showing the surface temperature distribution in the width direction of the rolled material. Fig. 5 is a graph showing the roll surface temperature distribution in the roll barrel direction, Figs. 6 and 7 are graphs showing the relationship between the roll rotation angle and the roll surface smoothness, and Fig. 8 is a graph showing the relationship between the roll rotation angle and the roll surface smoothness. FIG. 9 is an explanatory diagram showing an example, and FIG. 9 is a longitudinal sectional view of a conventional cooling device.

FIG. 1 is an example of a cooling device according to the present invention.

In the conventional technology, as shown in FIG. 9, the cooling header 8.9 is installed on the back side of the guide on the roll exit side (on the side opposite to the pass line), and the scraper 10 is in contact with the upper roll 1. There is no opening for cooling water to flow into the roll bite section. Even if a small gap is provided between the scraper 10 and the first roll 1 and the cooling water is allowed to flow through the gap, the flow will be against the direction of rotation of the upper roll, so a sufficient amount of water will be allowed to flow until the roll-by [・That is difficult. Therefore, the present invention provides upper and lower guide tip members 13.2 for guiding the rolled material 3.
Mist spray nozzles 18 and 27 for cooling the surface of the roll are installed directly in the roll bite section at both ends in the roll width direction on the surface facing the upper and lower rolls of No. 2, and fluid nozzles 18' and 27' are installed in the center. are installed, and cooling water is sprayed from each nozzle onto the roll surface on the exit side of the roll bite to cool it.

Figure 2 shows the temperature distribution in the width direction of the rolled material.

The temperature of the edges of the rolled material is lower than that of the center, and when this is cooled with cooling water of the same flow density, the heat transfer coefficient α changes depending on the temperature between the center and edges, as shown in Figure 3. changes significantly, and as a result, the amount of heat removed from the end portion increases. Therefore, the temperature at the ends is lower than that at the center.

However, as shown in Fig. 1, by using a mist spray nozzle on the side of the roller pane, it is possible to effectively cool the roll surface on the end side with a small amount of water, and at the same time, the roll surface on the end side can be effectively cooled with a small amount of water. Since the temperature drop at the end of the rolled material can be reduced, it is possible to keep the temperature drop at the end of the rolled material small.

The configuration of the cooling device will be explained based on FIG.
゛A scraper is fixed to the upper roll side surface of the upper guide tip member 13, and a plurality of air supply holes 1G are provided inside in the width direction. Mist spray nozzles 18 communicating with the air supply water hole 1G are attached to both ends in the width direction of the roll, and a -fluid nozzle 18' is attached to the center. Similarly to the lower guide, mist spray nozzles 27 are installed at both ends in the width direction of the roll, and a fluid nozzle 27' is installed at the center. Figure 1 (b) shows the condition of the mouth.
Shown below.

Example This will be further explained below with reference to Examples.

FIG. 4 shows the measurement results of the temperature distribution in the width direction of the rolled material using the cooling device of the present invention.

FIG. 4 is a graph comparing the temperature distribution in the width direction of the material to be rolled when the roll surface immediately adjacent to the roll bite is cooled by a fluid nozzle and the temperature distribution in the width direction of the material to be rolled according to the present invention. It can be seen that with the cooling method, there is almost no decrease in temperature at the plate end compared to the case of a single-fluid nozzle.

Furthermore, the temperature distribution in the direction of the roll barrel when cooling with a fluid nozzle and the temperature distribution in the direction of the roll barrel when the end is cooled with a mist spray nozzle are shown in Figure 5. There is no difference in the cooling effect from a spray nozzle, and furthermore, the temperature drop of the rolled material is small, so it can be said that this method is far superior to the conventional cooling method using a single fluid nozzle.

Furthermore, when cooling is performed by this method, the O-lu filling degree after one rotation is reduced to 80° C., as shown in FIG.

On the other hand, in the case of no cooling shown in FIG. 7, the roll temperature after one rotation is 94°C, which is 14°C higher than the temperature of the present invention.

Also, compared to the air when mist spray nozzles are installed across the entire width, the air skewer according to the present invention is approximately 11'
2, and the running cost is about 1 that of full-width mist cooling.
・'2, which is extremely economical.

In addition, if the plate width changes significantly, as shown in Fig. 8, pressure regulating valves 31 are installed in the air piping 32 and water piping 33, respectively, and the plate width is measured and adjusted to correspond to the plate width. Suitable roll cooling W can be achieved by setting the air pressure at the center to OkQ,'-, setting the water pressure to a predetermined pressure, and setting both the air pressure and water pressure to the predetermined pressures at the plate ends.

<<Effects of the Invention>> As explained above, one aspect of the present invention is to spray mist on both ends of the rolls on the surfaces facing the upper and lower rolls of the upper and lower guide tip members respectively attached to the exit side upper and lower guide devices that guide the rolled material. It is characterized by having a nozzle and a fluid nozzle in the central part, and with this configuration, it is possible to effectively cool the work roll by minimizing the temperature drop of the material to be rolled, and Since the amount of air used can be reduced, economical cooling can be achieved.

[Brief explanation of the drawing]

FIG. 1(a) is a longitudinal cross-sectional view of an example of the cooling device according to the present invention, FIG. 1(b) is an enlarged front view of the nozzle part, and FIG. 2 shows the temperature distribution in the width direction of the rolled material. Figure 3 is a graph showing the relationship between the cooling water base and heat removal, Figure 4 is a graph showing the surface temperature distribution in the width direction of the rolled material, and Figure 5 is the graph showing the roll surface temperature distribution in the roll barrel direction. 6 and 7 are graphs showing the relationship between roll rotation angle and roll surface temperature, respectively. FIG. 8 is an explanatory diagram showing an application example of the present invention. FIG. 9 is a vertical cross section of a conventional cooling device. It is a diagram. Code 1... Upper work roll 2... Lower work roll 3... Rolled material 4... Upper mountain side guide 5... Not appearing Side guide G, 7...Bin 8.9...Cooling water header 10...Scraper 13...F guide tip member 22... Lower guide tip member 18.27...Mist spray nozzle 18'
, 27'...-Fluid nozzle 30...
・Adjuster 31...Pressure regulating valve 32...Air piping 33...Water piping

Claims (1)

[Claims] Mist spray nozzles are provided at both ends of the rolls on the surfaces facing the upper and lower rolls of the upper and lower guide tip members respectively attached to the exit upper and lower guide devices that guide the rolled material, and a fluid nozzle is provided at the center. Features of a work roll cooling device for hot rolling mills.