JPH027866Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a water injection nozzle, and more specifically to a nozzle that injects cooling water used when cooling steel materials, etc. This invention relates to a simple water injection nozzle with high cooling capacity.

[Conventional technology]

In the steel industry, rapid cooling of steel plates from a high-temperature red-hot state is used to improve the mechanical properties of steel plates.
So-called quenching or accelerated cooling treatment is performed. As a cooling means for this process, a method is adopted in which water is injected onto the upper and lower surfaces of the steel plate.

When cooling the upper and lower surfaces of a steel plate by injecting water, special attention must be paid to how efficiently and uniformly the lower surface can be cooled.
On the upper surface of the steel plate, the water injected from the nozzle stays on the upper surface of the steel plate, is dispersed relatively uniformly over the entire surface of the steel plate, and efficiently performs secondary cooling.
On the other hand, water jetted from a nozzle on the lower surface of a steel plate has a cooling effect at the part where it collides with the steel plate, but after the collision, it immediately falls away from the lower surface of the steel plate and does not have any cooling effect, so it is uniform and Efficient cooling is difficult. Such problems are more or less common to all types of nozzles in the prior art, such as spray nozzles, drill hole nozzles, laminar flow nozzles, etc., and how to solve them is a problem that It was a big challenge.

On the other hand, the inventors of the present invention have constructed a plurality of holes 2C that eject water substantially horizontally from the side surface of the elongated header 2 whose axis is substantially horizontal, as shown in the cross-sectional view in FIG. A guide plate 3 is provided in both side walls of the header and has an elongated shape whose cross section is curved approximately in the shape of a quarter circumference, and is recessed upward in the both side walls of the header in order to direct the ejected water flow upward. A water injection nozzle 1 for cooling the lower surface of a cooled material has been developed and put into practical use. (Tokugansho
57-137968) This water injection nozzle 1 injects cooling water upward along the inner surface of the guide plate 3, and this injected water stream W ₁
When the water collides with the lower surface of the material to be cooled, it is divided into two directions: the direction of movement of the material to be cooled and the opposite direction, and a branched water flow W ₂ ,
Form W ₃ . One of these branched water streams W ₂
flows away from the header along the lower surface of the material to be cooled, and then falls downward; the other water flow _W3 temporarily flows along the lower surface of the material to be cooled 4 in the direction of the central axis of the header 2; Above the header, the water collides with the divided water flow coming from the opposite side, changes its direction downward, and falls to approximately the center of the upper surface of the header, where it is collected. Furthermore, the water that has fallen onto the header flows to both sides along the outer surface of the header, enters the guide plates attached to both side walls of the header, merges with the water flow spouted from the holes in the header, and is blown out by the water flow. The water becomes energized and rises again as part of the rising water flow. As a result, the amount of cooling water jetted from the water injection nozzle is 2 times the amount of water supplied to the header.
This has significantly increased cooling water usage efficiency compared to conventional nozzles, making it possible to significantly improve cooling capacity.

[Problem that the invention attempts to solve]

However, the water injection nozzle 1 can easily blow the above-mentioned recovered water upward again when the amount of water ejected from the header hole is large and the water velocity is high, but when the amount of water ejected from the hole is small, Since the guide plate 3 has a curved shape in the shape of a quarter circumference, there is a problem that a stable rising water flow _W1 cannot be formed due to the following reasons, and an immediate improvement has been desired. In other words, recovered water accumulates in the depression formed by the inner plate and the side of the header, and this accumulated water obstructs the progress of the water gushing out from the hole. It even blocks the blowing up of the gushing water itself.

The water ejected from the hole attenuates its kinetic energy as it flows along the inner surface of the guide plate. This is due to the long path length of the water flowing along the curved guide plate.

The present invention aims to provide an improved water injection nozzle that takes advantage of the advantages of the water injection nozzle and solves the above problems.

[Means for solving problems]

The present invention was devised to effectively solve the above-mentioned problems of the water injection nozzle, and its main points are: (A) A water injection nozzle for cooling the bottom surface of a material to be cooled such as rolled steel. (B) a pair of guide plates having substantially vertical wall surfaces on both sides of the header, extending over the entire length of the header and extending above the top surface of the header; (C) Partition plates are attached to both ends of the header in the longitudinal direction so as to protrude above the top surface of the header; (D) Partition plates are attached to the guide plate at positions close to the guide plate. It is equipped with a plurality of nozzle tips that spray pressurized water inside the header obliquely upward toward the inner surface from diagonally downward.

[Effect]

The present invention is based on the advantages of the conventional water injection nozzle, namely, high water usage efficiency and high cooling capacity due to the circulation of cooling water during water recovery, and the ability to blow up water flowing along the guide plate. The continuous water film in the longitudinal direction of the header maintains the excellent effects of uniformly cooling the material to be cooled, and further reduces the amount of collected water that accumulates, allowing for sufficient water to be blown up even when a small amount of water is ejected. In addition to giving the ability, the collected water is stored in the upper part of the header,
This effectively prevents thermal deformation of the header due to radiant heat from the hot steel plate passing above the water jet nozzle when water is not jetted, that is, when cooling is not performed.

〔Example〕

The details of the present invention will be explained below based on examples.

1 to 4 show an embodiment of the present invention, and FIG. 1 shows a state in which the device is installed under a material to be cooled 4 conveyed by a table roller 5 and water is being sprayed. A cross-sectional view of an embodiment of the present invention, FIG. 2 is a cross-sectional view of the embodiment (A-A arrow view in FIG. 3),
FIG. 3 is an overall plan view, and FIG. 4 is a side view.

The water injection nozzle 10 of the present invention has a header 11, a nozzle tip 12 and a guide plate 13, and partition plates 15 and 16 incorporated into the header 11 as main components.

The header 11 is arranged so that its axis is substantially horizontal, has a rectangular cross-section, and has the shape of an elongated hollow pipe, and has a size necessary to inject supply water almost uniformly from each part in the longitudinal direction of the header 11. It has a cross-sectional area of Partition plates 15 and 16 are provided at both ends of the header 11 in the longitudinal direction, and
A flange 14 connected to a pressurized water supply pipe (not shown) is provided on the partition plate 16 side. Furthermore, header 1
It goes without saying that pressurized water can be supplied to the header 1 not from the end of the header 11, but by closing both ends of the header 11 and connecting a water supply pipe perpendicular to the header 11 midway through the header from below.

The header 11 has vertical guide plates 13 attached to both side walls thereof along the longitudinal direction.
The guide plate 13 is provided to protrude upward from the top surface of the header 11, forms a water reservoir on the top surface of the header, and guides the flow direction of the water jetted from the nozzle tip 12 to be changed upward. .

On the wall surface of the upper corner of the header 11, as shown in FIG.
The guide plates 13 are embedded in the guide plate 13 so that the ejected flow collides with the guide plate 13. If the angle α with the horizontal plane exceeds 80°, the effect of the guide plate 13 cannot be expected. Incidentally, the angle α between the central axis of the nozzle tip 12 and the horizontal plane is 10 to 10, according to experiments by the inventors.
A range of 70° is preferable, and the best cooling water injection condition was obtained at approximately 45°.

The nozzle tip 12 has a predetermined diameter, e.g.
It is a pipe-shaped cylinder with a hole diameter of about 10 mmφ, one end of which communicates with the inside of the header 11, and the other end of which is open to the atmosphere, so that the pressurized water in the header 11 flows from one end of the nozzle tip 12 to the outside. gush.

The water ejected from the nozzle tip 12 collides with a guide plate 13 located in front of the nozzle tip 12 and attached and fixed to the side surface of the header 11.
After flowing temporarily along the guide plate 13, the water is blown upward and reaches the lower surface of the material to be cooled ₄ as an ascending water flow W1 shown in FIG.

When the water ejected from the nozzle tip 12 collides with the wall surface of the guide plate 13 and flows along the wall surface, it combines with the water flow from other adjacent nozzle tips,
Above the guide plate 13, a continuous water film is formed in the longitudinal direction of the header 11, and the lower surface of the material to be cooled 4 can be uniformly cooled.

The distance S between the upper end of the guide plate 13 and the upper end of the upper wall surface of the header 11 is determined by the distance S between the upper end of the guide plate 13 and the upper wall surface of the header 11. It is determined by the minimum wall surface height required to meet the nozzle tips and change the flow direction upward, and in this embodiment, the embedding angle of the nozzle tip 12 is 45 degrees and S=10 mm.

As shown in FIG. 1, part of the cooling water injected onto the lower surface of the cooled material ₄ falls onto the upper surface of the header 11, and is energized by the water jetted from the nozzle tip 12 and blown upward again.

The water that falls onto the top surface of the header 11 and is collected is
It stays on the header 11 by the wall surface of the upper part of the header 11, the inner wall of the guide plate 13 provided on both sides of the header 11, and the partition plates 15 and 16 provided at both ends of the header in the longitudinal direction.

This is because the depth of the cooling water collected and retained in the upper part of the header is determined by the height of the guide plate 13 protruding above the header, that is, the distance S between the upper end of the guide plate 13 and the upper wall surface of the header 11. This means that the distance between the upper surface of the retained water and the outlet of the nozzle tip 12 can be reduced. This means that the water injection nozzle 10 according to the present invention can flow along the inner wall surface of the guide plate 13 without the speed of the ejected water being attenuated by the accumulated water even when ejecting a small amount of water, and can send a stable water flow to the cooled material. This is one of the reasons why it can be sprayed onto the bottom surface.

As mentioned earlier, the water injection nozzle 10 of the present invention has a structure in which the height of the guide plate 13 is made as low as possible, and the resistance to the water flowing along the wall surface of this guide plate is minimized. In addition to the small amount of water, it is possible to always blow up a stable water flow toward the lower surface of the material to be cooled.

Furthermore, a feature of the water injection nozzle 10 of the present invention is that cooling water can be stored in the upper part of the header 11 when cooling is not being performed, and it can be protected against radiant heat from a red-hot steel plate passing above. It is now possible to effectively eliminate the reduction in equipment life due to corrosion, etc.

[Effect of idea]

As is clear from the above explanation, according to the water injection nozzle of the present invention, a part of the cooling water can be recovered and reused for circulation, so it has a high cooling capacity and uniformly sprays the material to be cooled. In addition to realizing cooling, the cooling water that remains on the top surface of the header prevents deterioration of the device due to heat, making it possible to extend the life of the device.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the water injection state of the embodiment of the present invention, Fig. 2 is a transverse sectional view of the embodiment of the present invention (viewed from arrow A-A in Fig. 3), and Fig. 3 is the cross-sectional view of the embodiment of the present invention. FIG. 4 is a plan view, FIG. 4 is a side view thereof, and FIG. 5 is a cross-sectional view of a conventional water injection nozzle. 10... Water injection nozzle, 11... Header, 1
2... Nozzle tip, 13... Guide plate, 15,1
6... Partition board.

Claims (1)

[Scope of utility model registration request] A pair of guide plates having substantially vertical wall surfaces are attached to both side walls of an elongated header whose axis is substantially horizontal, projecting upward from the upper surface of the header over the entire length of the header, and extending in the longitudinal direction of the header. Partition plates are attached to both ends of the header so as to protrude upward from the upper surface of the header, and a plurality of nozzle tips are attached to the inner surface of the guide plate for ejecting pressurized water in the header obliquely upward. Water injection nozzle for cooling the underside of the coolant.