JPH0437875Y2 - - Google Patents

Description

[Detailed explanation of the idea]

"Industrial Application Field" This invention relates to the improvement of a nozzle for controlled cooling in wire rod and steel bar rolling. "Prior Art" In hot rolling of wire rods, steel bars, etc., inter-mill cooling and post-finishing mill cooling are performed for the purpose of improving mechanical properties, controlling scale, etc. For this cooling, initially, as shown in Fig. 3, a cylindrical guide 3 was attached to an annular nozzle 2 with a slit 1 around the circumference for cooling water injection.
A shower system was adopted in which a water cooling zone was formed by combining several of these. Note that 4 is a water supply port. However, this nozzle has a high cooling ability in the part that directly contacts the rolled material, but a low cooling ability in other parts, and the overall cooling efficiency (for example, temperature drop/water supply amount) is low. For this reason, cooling nozzles with various improvements have been proposed in the past, and water-sealing type nozzles in which the inside of a cylindrical guide is filled with cooling water have been provided.
According to this, the high-temperature wire material running along the shaft center of the cylindrical guide is immersed in the cooling water that fills the cylinder, which increases the contact time with the cooling water and prevents it from being uniformly cooled. Therefore, an extremely high cooling capacity can be obtained. For example, in the one disclosed in Japanese Patent Application Laid-open No. 59-226123, as shown in FIG. In a nozzle for immersing and cooling a wire rod or rod that runs through the axial center of the cylinder, the cooling water is jetted inward from the cylinder to fill the inside of the cylinder. One or more drainage ports 6,..., 7 are provided along the longitudinal direction on the upper and lower surfaces, and cooling water is supplied from both ends of the cylindrical guide 3, and from the middle part of the cylindrical guide 3 in the longitudinal direction. Drain and drain outlet 6,
By optimizing the cross-sectional area of 7, the effective replacement rate of cooling water (the ratio of the amount of water discharged from the drain port to the amount of cooling water supplied) is increased, thereby increasing the cooling capacity. ``Problem to be solved by the invention'' However, in the nozzle with the above configuration, the drain port 7 is provided large at the bottom, so there is a minimum flow rate to fill the cylindrical guide 3 with cooling water, but this is not an issue due to equipment considerations. If the difference between the maximum flow rate (water supply capacity) and this minimum flow rate is large, the cooling control range can be widened, which is desirable. (The minimum flow rate is also smaller). On the other hand, if the area of the drain port 7 is made smaller, the pressure inside the cylindrical guide 3 will increase, the amount of discharge from the inlet and outlet sides of the cooling nozzle will also increase, and the amount of flowing water that does not contribute to cooling will increase (decreased cooling capacity). In addition, the water discharged from the inlet and outlet sides of the cooling nozzle is
If the amount of water is increased, it will scatter and cause disturbance to the cooling of the material, which is not desirable. ``Means for solving problems'' and ``effects'' The present invention was developed in view of the above circumstances, and its gist is that an annular nozzle with a pass line axis as its central axis is inserted into a cylindrical guide. In a water-sealed type cooling nozzle installed in the direction of spraying inside the cylindrical guide on the side and outlet side, by opening the upper part of the cylindrical guide, it is possible to eliminate splashing water due to discharge from the nozzle inlet and outlet side, and to reduce the The point is that it is possible to achieve a high cooling capacity and to minimize the minimum flow rate of cooling water. "Example" This will be described in detail below based on the drawings. 1 and 2 are a pass-line vertical sectional view of the nozzle of the present invention, and a right-angled sectional view taken along arrow A in FIG. Reference numeral 8 in the figure indicates an upper open guide attached between the annular nozzle 2 on the inlet and outlet sides of the cooling nozzle 9, which has a structure in which the upper part of a conventional cylindrical guide is open. A side wall 10 is provided to prevent non-cooling due to the drop, and its top height H is set higher than the inner diameter Di of the cooling nozzle. This top height H is 1.5× due to the generation of waves in flowing water, etc.
Although it is desirable to take it to about Di, this is not a particular problem from the gist of the present invention. Further, L indicates the typical length of the nozzle 9, and t indicates the slit width. By opening the upper part of the guide between the annular nozzles 2 and 2 on the inlet and outlet sides of the water seal type cooling nozzle, the seal water pressure (based on nozzle bottom B) can rise above the top height H. Therefore, the water discharged from the inlet and outlet sides of the cooling nozzle 9 can be reduced to zero (disturbance due to splashed water cooling is zero), and 100% of the water is injected from the slit 1 of the annular nozzle 2, and the water is 100% injected from the slit 1 of the annular nozzle 2.
As it passes through the inside and cools the material, high cooling capacity can be achieved. Note that drainage is performed by overflowing from the top end of the side wall 10 of the open portion. In this configuration of the present invention, since a lower drain port is not provided, the minimum flow rate can be minimized,
It can be seen that this allows a wide range of cooling capacity control. Hereinafter, specific effects will be described using examples of the present invention. As shown in the table below, for a cooling nozzle with Di=80 mm and length L=1 m, the minimum flow rate of the present invention is about 1/4 smaller.

[Table] Additionally, the amount of water discharged from the nozzle inlet and outlet sides is almost zero, as shown in the table below.

[Table] Furthermore, as shown in the table below, the cooling capacity of the present invention is higher.

[Table] "Effects of the Invention" As is clear from the above, the effects of the present invention are very large, and stable cooling control can be performed without splashing water due to discharge from the inlet and outlet sides of the nozzle.

[Brief explanation of the drawing]

Figures 1 and 2 are pass line vertical cross-sectional views of the nozzle of the present invention, right-angle cross-sectional views taken in the direction of arrow A in Figure 1, and Figure 3.
FIG. 4 is a vertical cross-sectional view of a conventional cooling nozzle. 1... Slit, 2... Annular nozzle, 3... Cylindrical guide, 4... Water supply port, 6... Drain port, 7...
Drain port, 8...Top opening guide, 9...Cooling nozzle, 10...Side wall.

Claims (1)

[Scope of utility model registration request] A water-sealing type cooling nozzle in which annular nozzles centered around the pass line axis are attached to the inlet and outlet sides of a cylindrical guide in a direction that injects water into the cylindrical guide, and the upper part of the cylindrical guide is open. Cooling nozzle for wire rods and steel bars.