JPH10158796A - Device for preventing adhesion of foreign matter on bath surface within snout to strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhesion of the foreign matter on the plating bath surface in a snout to a strip by providing the inside of the snout with gas ejection nozzles and blowing inert gases to the front and rear of the traveling strip right after hot dip coating. SOLUTION: This device 10 for preventing the adhesion has a pair of the slit nozzles 14, 15 facing the inside surface of the snout 13 disposed along the pass line of the strip 12 in a hot dip metal coating bath vessel 11. The slit nozzles 14, 15 are made of stainless steel sheets and have gas feed ports 17, 18 on the rear surface side. The front surface side is formed to a rectangular shape of approximately the same width as the width of the strip 12 and has opening slits of a narrow width (1mm) formed along their four sides. The slit nozzles 14, 15 are so arranged that their bottom ends exist at a height of about 100mm from the plating bath surface. The nozzles are arranged to face each other apart about 5mm spacing from the traveling strip. At the time of operation, gaseous N2 of 200 to 500 deg.C is blown from a gas feed port 18 and is ejected at a wind velocity of 25 to 30m/sec from the slit nozzles 14, 15 and is made to flow out in an arrow direction on the plating bath surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to aluminum,
Stripping of foreign materials floating on the bath surface such as bath surface oxides (scum) in the snout and alloy compounds generated in the bath in hot-dip metal plating such as tin and zinc (mainly steel plate)
Device that does not adhere to

[0002]

2. Description of the Related Art There is a problem in that oxides and other compounds float in a snout in hot-dip metal plating of aluminum, tin, zinc or the like, and if these adhere to steel sheets, the quality of plated products is impaired. Therefore, Japanese Patent Application Laid-Open
As disclosed in Japanese Patent Publication No. 276052, a non-oxidizing gas is blown from one of the strips passing through the snout to bias the levitating foreign matter to one side of the snout to prevent the foreign matter from adhering to the strip. Was. Further, Japanese Utility Model Laid-Open No. 7-6260 discloses that a non-oxidizing gas is blown out while being directed to a wide surface of a strip passing through a snout and further inclined toward a bath surface to remove foreign substances in the snout from the vicinity of the strip. A device has been proposed.

[0003]

However, the strip passing through the snout is transported at a high speed while being supported by the upper turn roll and the lower bath roll, and the distance between the turn roll and the bath roll. Is large, so that the strip vibrates into the bath while vibrating, which causes the bath surface to undulate,
It has not been solved by any of the techniques disclosed in the above publications. The present invention has been made in view of the above circumstances, and provides a device for preventing foreign substances from adhering to a strip in a snout, which transports the strip at high speed without vibrating the strip and eliminates the adhesion of foreign substances due to the waving of the bath surface. The purpose is to do.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
The device for preventing the adhesion of foreign substances on the bath surface in the snout to the strip is a device for preventing foreign substances floating on the plating bath surface from attaching to the strip passing through the snout installed in the hot-dip plating bath, A slit nozzle for blowing an inert gas from a direction facing the strip is provided on both sides of the strip. Further, in the apparatus for preventing foreign matter from adhering to the strip on the bath surface of the snout according to claim 2, in the apparatus according to claim 1, the slit nozzle has a rectangular outer slit formed over the entire width direction of the strip. And an inner slit which is arranged inside the outer slit and generates a static pressure at the center.

According to the first and second aspects of the present invention, in the apparatus for preventing foreign matter from adhering to the strip in the snout bath, a slit nozzle for blowing an inert gas from a direction facing the strip is provided near the front and back of the strip. ing.
As a result, the passing strip is supported by the airflow blown from the slit nozzle, and as a result, the vibration of the strip can be suppressed. Therefore, the surface of the bath is less likely to undulate, and the strip of foreign matter does not adhere to the bath. In particular, in the apparatus for preventing adhesion of foreign matter on the snout bath surface to the strip according to claim 2, since the slit nozzle has a rectangular outer slit formed over the entire width direction of the strip and an inner slit, A static pressure is generated at the center of the inner nozzle, thereby more reliably supporting the strip from the front and back, and suppressing the occurrence of vibration.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is a cross-sectional view of an apparatus for preventing foreign matter from adhering to a bath surface in a snout according to an embodiment of the present invention, FIG. 2 is a front view of a slit nozzle used in the apparatus, and FIG. It is a front view of the slit nozzle concerning an embodiment. As shown in FIGS. 1 and 2, an apparatus 10 for preventing foreign matter from adhering to a bath surface in a snout according to an embodiment of the present invention is provided in a bath 11 of molten metal along a passing line of a strip 12. A pair of slit nozzles 14 and 15 are provided in the snout 13 provided.

The slit nozzles 14 and 15 are made of a stainless steel plate, have air supply ports 17 and 18 on the back side, and have a rectangular shape having the same width as the strip 12 on the front side. Each slit nozzle 14,
As shown in FIG. 2, an outer slit 19 formed of a narrow (1 mm) opening formed along four sides of a rectangle as a whole, and a diamond-shaped And an inner slit 20 formed along the side and having a narrow (1 mm) opening. The outer slit 19 and the inner slit 20 are provided with connecting pieces (not shown) having a small width at an appropriate pitch, and by providing the slits, the inner plate is not separated from the outer plate.

The slit nozzles 14, 15 are arranged so that their lower ends are at a height of about 100 mm from the bath surface, and are arranged to face the strip 12 passing therethrough with a gap of about 50 mm. ing. Heated high temperature (about 200 to 500
C), and N ₂ gas, which is an example of a non-oxidizing gas at a high pressure, is blown into the outer slits 19 of the slit nozzles 14 and 15.
An air current having a wind speed of about 25 to 35 m / sec blows out from the inner slit 20. As a result, a static pressure is created at the center of the inner slit 20 and the strip 1
2 from both sides and strip 1
The N ₂ gas that has flowed downstream due to 2 flows on the bath surface away from the strip 12 as shown by the arrow, and foreign matter such as scum on the bath surface is pushed to both sides of the snout 13.

Therefore, the bath surface in the vicinity of the entrance of the strip 12 is clean, and the strip 12 is supported from the front and back by the static pressure formed by arranging the slit nozzles 14, 15, so that the strip 12 is transported. No vibration occurs in the strip 12. As a result, no undulation occurs on the surface of the molten metal, and it is possible to prevent foreign substances attached due to the undulation.

In the above embodiment, the shape of the inner slit 20 is rhombic. However, as shown in FIG. 3, the present invention is also applicable to a case where a square inner slit 22 is further concentrically provided in the outer slit 19. You. Further, in the above-described embodiment, N ₂ gas is used as the non-oxidizing gas, but other non-oxidizing gas (for example, argon gas) or the like can be used.

[0011]

According to the first and second aspects of the present invention, the apparatus for preventing foreign matter from adhering to the strip on the bath surface of the snout, as is apparent from the above description, actively utilizes the flow of the non-oxidizing gas blown from the slit nozzle. Then, since the passing strip is held, the strip does not vibrate, thereby eliminating the waving of the molten metal surface. Therefore, the adhesion of foreign matter to the strip due to the undulation of the molten metal surface is eliminated. In addition, since gas blown from the slit nozzle is blown onto the bath surface along the strip, foreign substances generated around the strip are also pushed to the side of the snout, thereby plating without stripping foreign substances on the strip. We can do it and provide good quality products.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an apparatus for preventing foreign matter from adhering to a strip in a snout bath according to an embodiment of the present invention.

FIG. 2 is a front view of a slit nozzle used in the apparatus.

FIG. 3 is a front view of a slit nozzle according to another embodiment.

[Explanation of symbols]

Reference Signs List 10 Device for preventing foreign matter from adhering to the bath surface in the snout on the strip 11 Bathtub 12 Strip 13 Snout 14 Slit nozzle 15 Slit nozzle 15a Slit nozzle 17 Air supply port 18 Air supply port 19 Outer slit 20 Inner slit 22 Inner slit

Claims (2)

[Claims] 1. A device for preventing foreign substances floating on the surface of a plating bath from adhering to a strip passing through a snout provided in a hot-dip plating bath, wherein the device is inert from a direction facing the strip. An apparatus for preventing foreign matter from adhering to a strip on a bath surface in a snout, wherein slit nozzles for blowing gas are provided on both sides of the strip. 2. The slit nozzle has a rectangular outer slit formed over the entire width direction of the strip, and an inner slit disposed inside the outer slit to generate a static pressure at the center. 2. The apparatus for preventing foreign matter from adhering to a strip in a snout bath according to claim 1, wherein the substance is attached to the strip.