JPS627400Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a two-fluid spray nozzle that ejects a mixed flow of water and compressed gas from an outlet slit, and more specifically, the present invention relates to a two-fluid spray nozzle that ejects a mixed flow of water and compressed gas from an exit slit. This invention relates to the structure of a slit-type two-fluid spray nozzle that makes uniform fluid jetting, stabilizes the amount of jetted water, and enables accurate control over a wide range.

[Conventional technology]

In continuous cooling, in which a cooling medium is injected onto the front and back surfaces of a steel plate during heat treatment such as quenching, in order to ensure the homogeneity of the heat-treated material and prevent deformation, it is necessary to It is desirable to perform cooling uniformly in the width direction. A slit-type spray nozzle is used as a device for uniform cooling across the width.

As a slit-type spray nozzle, only high-pressure water is used, and the high-pressure water is distributed at predetermined intervals (outlet slit).
Single-phase fluid spray nozzles that cool steel materials and the like by spraying a film from a single-phase fluid are conventionally known. but,
Those that use only high-pressure water have a large amount of water jetted and a very large cooling capacity, so they are suitable for strong cooling of thick steel plates, etc., but they are suitable for materials that cool quickly such as thin steel plates. could not be used. Furthermore, it could not be used for heat treatment of steel materials, etc., which is performed while adjusting the cooling capacity by varying the amount of cooling medium.

Therefore, a two-fluid spray nozzle that uses both water and compressed gas has been proposed as a nozzle that can control the cooling capacity over a wide range and perform relatively uniform cooling. This two-fluid spray nozzle is a perforated type that spouts a mixed fluid of water and compressed gas (compressed air, etc.) from multiple injection ports (perforations) with circular cross sections provided at regular intervals in the width direction. It has been known. However, with this drill hole type, when the cooling medium is injected onto the surface of the treated material 12 such as a steel plate that is moving in the direction of arrow A as shown in FIG. Therefore, it was not possible to align the cooling pattern in a straight line at the cooling start position B, and it was difficult to make the quality of the heat-treated material uniform.

In order to solve this problem and achieve uniform cooling in the width direction, we have proposed a slit-type two-fluid spray nozzle in which the spout has a slit of a constant width and ejects a mixed flow of water and compressed gas. has been done. Figure 2 shows the structure of a conventional slit type two-fluid spray nozzle.
6 is provided, and the cooling water supply header 20 and the mixing chamber are connected by a slit-shaped gap 22, and the mixed fluid of compressed air and water that is combined in the mixing chamber is transferred to the tip. It is configured to be injected from an exit slit 24 onto a surface 26 of a processing material such as a steel plate in progress.

[Problem that the invention attempts to solve]

However, in such a conventional slit-type two-fluid spray nozzle, water is not sufficiently mixed and atomized into the air before being guided through the outlet slit 24, so the flow of air and water are reduced by the throttling action of the outlet slit. This had the drawback that it was interrupted intermittently, causing a hunting phenomenon due to pressure fluctuations with relatively short cycles, and that stable spraying could not be obtained.

The purpose of this invention is to solve the drawbacks of the conventional slit-type two-fluid spray nozzle, and it is possible to easily adjust the amount of water sprayed and to provide a stable spray nozzle regardless of the amount of water. The object of the present invention is to provide a slit type two-fluid spray nozzle that can maintain a mixed spray and perform proper and uniform cooling in the nozzle longitudinal direction (width direction of a moving steel plate).

[Means for solving problems]

That is, according to the present invention, in a slit-type two-fluid spray nozzle that ejects a mixed flow of water and compressed gas through an exit slit, two parallel fluid spray nozzles are arranged at a predetermined distance in the direction of movement of a steel plate. At least two or more throttle portions each having a surface are provided in the jetting direction, a chamber having a cross-sectional area larger than the cross-sectional area of the throttle portion is provided between the throttle portions, and the mixed flow of the water and compressed gas is directed to the throttle portions. Provided is a slit-type two-fluid spray nozzle for cooling a steel plate, characterized in that the spray is ejected from the outlet slit after passing through a chamber.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

A mixing chamber 32 communicating with a compressed gas supply header 30 such as compressed air or pressurized steam is formed, and a water supply header 34 such as pressurized cooling water is formed in the mixing chamber with a cut hole or a slit with a constant gap. They are communicated via a throttle passage 36. The mixing chamber, which has a relatively wide space, further includes a first constriction section 3 having two parallel surfaces spaced apart from each other with a predetermined gap.
8 to a chamber 40 having a larger cross-sectional area than the constriction. The chamber 40 communicates with an outlet slit 44 formed at the end of the constriction through a second constriction 42 having two parallel faces spaced apart from each other.

Since the slit type two-fluid spray nozzle shown in FIG.
The water supplied from the water supply header 34 through 6 mixes in the mixing chamber 32, and the water becomes fine droplets in the mixing chamber. The mixed fluid of water and compressed gas thus generated passes through the first constriction section 38 at high speed and advances into the chamber 40, and after its static pressure increases and the pressure is averaged, it passes through the second constriction section 42 again. passes at high speed and is ejected to the outside through the exit slit 44,
A film-like mixed spray stream 48 is formed. The mixed spray stream is injected as a cooling medium or the like onto the surface of the steel plate 12 in progress, for example.

In the embodiment shown in FIG.
and one chamber 40 between these, but it is also possible to have three or more throttle parts and two or more chambers between them, and the present invention has such a structure. It also includes.

According to the embodiments of the present invention described above, the following effects can be obtained.

As mentioned above, in the conventional slit-type two-fluid spray nozzle, the mixing chamber is directly connected to the outlet slit, so the flow of water and air is intermittently interrupted by the throttling effect of the outlet slit, so that the flow of water and air is intermittently interrupted. A hunting phenomenon occurred in the mixed spray flow ejected from the slit, and the spray state was unstable. However, in the present invention, two or more constricted parts are provided inside the nozzle, and a chamber with a large cross-sectional area is provided between these constricted parts, so that the first constricted part can interrupt the flow of water and air intermittently. Even if a hunting phenomenon occurs, the static pressure of the mixed fluid increases in the chamber provided on the downstream side and the pressure is averaged, so that the pressure fluctuation can be eliminated. After the pressure fluctuations are eliminated in one or more chambers, the mixed spray is passed through the constriction section again and ejected from the outlet slit, so that the mixed spray flow ejected to the outside can be maintained in a stable state. In this way, a mixed spray stream that always has a uniform water droplet density distribution in the width direction can be generated.

[Effect of idea]

As explained above, according to the thread type two-fluid spray nozzle for cooling steel plates of the present invention, it is possible to prevent the hunting phenomenon during jetting that occurs with conventional nozzles, and to obtain a stable mixed spray flow regardless of the amount of water. Furthermore, since it is possible to maintain a uniform spray state in the width direction, by using it for continuous cooling of steel plates, uniform cooling can be performed and steel plates of uniform quality can be manufactured.

In addition, in this invention, the constriction part for accelerating and rectifying the mixed fluid is formed with two parallel surfaces, so there is no need for a tapered shape like in the conventional exit slit part, and therefore it is easy to process. It is also possible to obtain a slit type two-fluid spray nozzle with excellent productivity.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the spray pattern when using a slit-type two-fluid spray nozzle, Figure 2 is a vertical cross-sectional view showing the structure of a conventional slit-type two-fluid spray nozzle, and Figure 3 is a diagram showing the structure of a conventional slit-type two-fluid spray nozzle. FIG. 2 is a sectional view showing the structure of a slit-type two-fluid spray nozzle for cooling a steel plate according to an embodiment. The symbols in the drawings indicate the following. 30...
...Compressed gas supply header, 32...Mixing chamber, 34...
...Water supply header, 38, 42... Throttle part, 40...
. . chamber, 44 . . . outlet slit, 48 . . . mixed spray stream, respectively.

Claims (1)

[Scope of utility model registration request] A slit-type two-fluid spray nozzle is provided in a direction perpendicular to the running direction of the steel plate in accordance with the running steel plate and spouts a mixed flow of water and compressed gas from an outlet slit, the spray nozzle being arranged at a predetermined interval in the running direction of the steel plate. At least two or more throttle parts each having two parallel surfaces arranged in the jet direction are provided, and a chamber having a cross-sectional area larger than the cross-sectional area of the throttle part is provided between the throttle parts, and the water and the compressed gas are A slit-type two-fluid spray nozzle for cooling a steel plate, characterized in that a mixed flow of a steel sheet is ejected from the outlet slit after passing through these constricted portions and spaces.