JPH0143397Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a gas injection nozzle that can appropriately control the amount of molten metal plating deposited according to changes in the width of the steel strip.

In galvanizing and other continuous molten metal plating lines, after plating is applied in the plating tank, in order to control the amount of plating deposited, superheated steam,
It is well known that gas such as heated air, heated _N2 gas, or combustion gas is continuously injected to blow off excess plating.

Conventionally, this type of gas injection nozzle for controlling the amount of plating has been used to match the maximum width of the steel strip, and for this reason, in the case of narrow steel strips, wasted gas is discharged from both sides of the nozzle in the width direction. There is a problem in that the combustion intensity increases due to the injection. Furthermore, in the method of changing the nozzle according to the change in the steel strip width, it is necessary to suspend the line operation during that time, and it is inevitable that workability and productivity will be significantly reduced.

For this reason, various studies have been made in the past, and for example, Japanese Patent Publication No. 52-31291 has been proposed. Specifically proposed in the publication is a method in which a groove is formed in the horizontal slit portion (injection port) of the upper and lower nozzles in the width direction of the nozzle, and a rod-shaped blocking body is slidably inserted into this groove.

However, in such a configuration, there is a groove in the horizontal slit of the nozzle that faces the part of the steel strip where the amount of plating adhesion is to be controlled, so the injected gas causes pressure loss and turbulence in this groove part, and the injection energy is reduced. This causes loss of gas and a decrease in pressure. Another disadvantage is that it is extremely difficult to clean the nozzle to remove clogged nozzles during line operation, and moreover, the turbulent airflow tends to cause splashes of zinc or the like to adhere to the nozzle orifices.

Furthermore, in Japanese Patent Application Laid-Open No. 52-141430, a groove is not formed in the horizontal slit portion, and an elastic layer is provided on the inlet side of the horizontal slit portion 3a in the hollow portion 4 communicating with the injection port 3, as shown in FIG. 3a. A configuration is described in which a rod-shaped blocking body 10 is slidably inserted in the nozzle width direction, and the blocking body 10 is bent due to the pressure difference between the inside of the hollow part 4 and the outlet side of the slit part 3a, and the horizontal slit part 3 is
The inlet side a is closed, and the injection width of the injection gas is adjusted by the insertion length of the blocking body 10.

However, in the above configuration, the injected gas whose path is blocked by the blocker 10 swirls inside the hollow part 4, gradually increases in size, and travels straight to the outside of the slit part 3a, as shown in FIG. This also affects the injected gas trying to exit the horizontal slit section 3.
This causes turbulence on the outlet side, and also causes loss of injection energy, decrease in pressure, and generation of splash as described above.

The present invention was devised to solve the above-mentioned disadvantages of the conventional technology, and its basic feature is that a gas flow passage partitioned by a partition plate is communicated with a hollow part to allow rectified gas to flow into the air. In addition to being able to feed the gas into the hollow part, an injected gas blocking body having a cross-sectional shape substantially the same as that of the hollow part can be slid in the nozzle width direction from both ends of the nozzle widthwise into the hollow part communicating with the injection port. The hollow part can be completely closed from both ends in the width direction of the nozzle by inserting the nozzle so that the nozzle is inserted in such a manner that

An embodiment of the present invention will be described below with reference to the accompanying drawings. First, FIG. 1 is a plan view of a nozzle according to the present invention, and FIG. 2 is a sectional view taken along line A-A in FIG. 1. In the figure, A is the nozzle body, and this nozzle body A is the second
As shown in the figure, it is composed of an upper nozzle 1 and a lower nozzle 2, and these upper and lower nozzles 1, 2
By combining these, an injection port 3, a hollow portion 4 communicating with the injection port 3, and a gas flow path 5 are formed.

Further, a plurality of partition plates 7 are arranged in parallel in the nozzle width direction in the gas flow passage 5, and the upper and lower nozzles 1 and 2 are connected to each other through spacers 9 by bolts and nuts 8 at appropriate positions on the partition plates 7. It has been concluded.

On the other hand, in the present invention, a jet gas barrier 11 having a cross-sectional shape substantially the same as that of the hollow part 4 is slidably inserted into the hollow part 4. This blocking body 11 is inserted from both ends of the nozzle in the width direction,
The tip portion 11a is formed to widen toward the injection port 3. Further, as a means for moving these blocking bodies 11, although a hydraulic cylinder 12 is used in this embodiment, other mechanical or electrical means such as a rack and pinion mechanism may be used as necessary. Moreover, here, the blocking body 11
After the shield member 11 moves and is inserted and fixed at a predetermined location in the hollow portion 4, it is preferable to simply seal a slight gap at the insertion opening of the blocking body 11 into the hollow portion 4 with a cover or the like.

The flange portion 13 of the nozzle body A described above is connected to a gas introduction pipe (not shown) with bolts or the like.

According to the present invention as explained above, by moving the blocking body 11 in the nozzle width direction according to the width of the steel strip, the jetting width of the gas can be freely adjusted. This results in energy savings. Furthermore, since there is no need to replace the nozzle depending on the width of the steel strip, workability and productivity are improved.

Furthermore, compared to the conventional method of forming a groove in the horizontal slit and inserting a blocking body into this groove, there is no need to modify the existing nozzle (there is no need to form a groove, etc.), so it is less expensive. It is also inexpensive, and since there are no grooves, no pressure loss or turbulence occurs, and it is possible to prevent the loss of injection energy and decrease in pressure. Furthermore, the nozzle injection port can be cleaned easily and molten metal splash caused by turbulence is reduced, and various other excellent effects can be obtained, making this a highly practical idea. In addition, the inserted blocking body completely blocks the hollow part by the amount of insertion, which caused problems with conventional means of inserting an elastic rod-shaped blocking body into the entrance side of the horizontal slit. This eliminates the occurrence of turbulence of the injected gas within the hollow portion and the occurrence of defects such as splash adhesion.

[Brief explanation of the drawing]

Figure 1 is a plan view showing one embodiment of the present invention;
The figure is a sectional view taken along the line AA in FIG. 1, and FIGS. 3a and 3b are sectional views showing a conventional injection nozzle structure.

Claims (1)

[Scope of utility model registration request] In a nozzle that controls the amount of molten metal plating adhered to a steel strip by continuously spraying and blowing off gas, a gas flow passage partitioned by a partition plate is connected to a hollow part and the rectified gas is blown away. In addition to making it possible to supply gas to the hollow part, an injection gas shield having a cross-sectional shape substantially the same as that of the hollow part is inserted into the hollow part communicating with the injection port so as to be slidable from both ends in the width direction of the nozzle. A gas injection nozzle for controlling the amount of molten metal plating deposited, characterized in that the hollow portion can be completely closed from both ends in the width direction of the nozzle.