JPH0735591B2 - Pickling pretreatment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a pickling pretreatment device in a pickling facility for stainless steel strip.

<Prior Art> The scale of a rolled and heat-treated stainless steel strip (hereinafter referred to as a strip) is removed by pickling, and the surface is finished. As a pretreatment of this pickling,
For example, by dipping the strip in a molten salt bath prepared by mixing NaOH, NaNo ₃ and NaCl and melting at 400-500 ° C, the scale is chemically reacted to shorten the pickling time and improve the glossiness of the surface. There is. This pretreatment is applied to strips after cold rolling of all steel types such as austenitic, ferritic and altensitic.

Such pre-pickling treatment is performed by the apparatus shown in FIG. That is, for example, rolled into a very thin plate to about 0.2mm,
The strip S heat-treated in a heating furnace (not shown) is cooled to 450 to 500 ° C. by the fog quench 60 and fed to the salt bath 70 through the asbestos roll 61. In the salt bath 70, the strip S is dipped in the molten salt bath L, and is guided by both dipping rolls 71 to run,
It is sandwiched between the ringer roll 72 and the deflector roll 73 on the outlet side of, and the molten salt adhering to its surface is removed,
The film thickness is reduced. Next, the strip S cooled to almost room temperature by the water quench 80 is fed to the electrolytic pickling tank 90 via the centering roll 81 with the surface wet with the cooling water W, and the scale on the surface is removed. .

The traveling speed of the strip S in the conventional pickling equipment as described above is about 30 to 70 m / min.

<Problems to be Solved by the Invention> However, the above-mentioned conventional apparatus has the following problems.

(1) In the salt bath 70, molten salt having a low friction coefficient intervenes between the dipping roll 71 and the strip S, and both of them slip, causing scratches on the strip S. In addition, the scale separated from the strip S is between the dipping roll 71 and the strip S, the ringer roll 72 and the deflector roll.
It enters between 73 and the strip S, and the strip S is indented and scratched. These problems have been a major obstacle to speeding up pickling equipment.

(2) In the heating furnace (not shown), the tension of the strip S cannot be increased, and the strip S of the entire line cannot be tensioned.
Since the tension of the strip S is adjusted to the tension in the furnace, the tension of the strip S is small and the strip S is easily meandered, and the strip S is bent in the electrolytic pickling tank 90 and its strip-passing property is deteriorated.

In addition, a bridle is placed on the outlet side of the water quench 80, which cools the strip S to almost room temperature, and the electrolytic pickling tank 90 is installed.
Even if an attempt is made to increase the tension of the strip S inside, since the surface of the strip S is wet with the cooling water W, the bridle roll slips, the tension fluctuates, and scratches occur, and it is difficult to control the entire line. Becomes

The present invention has been proposed to solve the above problems,
Improves strip passing through the pickling tank and prevents meandering of the strip and slipping of each roll,
It is an object of the present invention to provide a pickling pretreatment device capable of preventing the surface of the strip from being scratched and coping with speeding up of the line.

<Means for Solving the Problems> A structure of the present invention that achieves such an object is a stainless steel band in which a water quench is disposed on the inlet side of a pickling tank, and a salt bath is disposed on the inlet side of the water quench. In the steel pickling pretreatment apparatus, in the molten salt bath of the salt bath, a salt floater for injecting molten salt to guide the stainless steel strip in a non-contact manner is internally provided, and at the outlet side of the salt bath, An air wiper is provided to blow off the molten salt adhering to the stainless steel strip with air.Furthermore, a direction changing means for the stainless steel strip is installed on the inlet side of the water quench, and a stainless steel strip is provided on the outlet side of the water quench. It is characterized in that it is provided with a suction bridle for adsorbing steel by negative pressure and applying a constant tension thereto.

<Operation> When the strip is immersed in the molten salt bath in the salt bath and runs, the strip is guided in a non-contact manner by the molten salt ejected from the salt floater, so that friction and scratches do not occur. The molten salt adhering to the surface of the strip drawn out from the salt bath is blown off by the air ejected from the air wiper, and the film thickness is reduced. After that, the direction is changed and it is sent to Water Quench.
A strip cooled by water quench and wet on both sides with cooling water is adsorbed on a suction bridle and wound around, and a certain tension is applied while preventing slippage.

<Examples> Hereinafter, the present invention will be described with reference to Examples. still,
The same parts as those of the conventional technique shown in FIG.

FIG. 1 shows a first embodiment of the present invention.

As shown in the figure, the strip S cooled by the fog quench 60 passes through the salt bath 10, water quench 80, etc.,
It is pickled in the electrolytic pickling tank 90. Where salt bath
A molten salt bath L is provided in the container 10, and a pair of salt floaters 11 are also provided in the container 10. As shown in FIG. 2, the salt floater 11 has a large number of ejection ports 11a for ejecting molten salt formed on a curved surface for guiding the strip S.
The width is wider than the plate width of the strip S.
Centering guides 12 are erected on both sides of the curved surface of the salt floater 11. Both salt floaters 11
Is connected to a pump (not shown) via a feed pipe 13.

This pump is a tank that stores molten salt in the salt bath 10.
14 and the discharge pipe 15 are connected. Therefore, the tank 14
The molten salt L1 sent to the salt floater 11 through the discharge pipe 15 and the pump through the inlet pipe 13 is jetted from the jet outlet 11a, guides the strip S in a non-contact manner, and returns to the tank 14. Become.

Further, an air wiper 20 is provided on the outlet side of the salt bath 10. The air wiper 20 includes a pair of jet nozzles arranged to face both sides of the strip S.
It consists of 21. The jet nozzle 21 is formed with the same width as the salt floater 11 to form a slit nozzle 21a longer than the plate width of the strip S, and is connected to a hot air source (not shown) via an air supply pipe 22. Therefore, the high-temperature (for example, 300 ° C) air sent from the hot air source is not supplied to the air pipe 2
It is sent to the jet nozzle 21 through 2 and slit nozzle 2
Molten salt adhering to both surfaces of the strip S is blown off from the la 1a to blow off the molten salt to form a thin film having a thickness of, for example, 5 μm.

A tray 16 for collecting the blown down molten salt is provided on the outer side of the tank 14 below the air wiper 20.

Further, above the air wiper 20, the water quench 80
A floater 31 is arranged on the entry side of the as a direction changing means. The floater 31 has a large number of jet ports 31a for jetting air formed on the curved surface that guides the strip S, and the width thereof is almost the same as that of the salt floater 11. Centering guides 32 are provided on both sides of the curved surface of the floater 31.
Is erected. The floater 31 is connected to a fluid pressure source (not shown), such as an air compressor, via an air supply pipe 33. Therefore, the air sent from the fluid pressure source through the air supply pipe 33 is jetted from the jet port 31a of the floater 31 to redirect the strip S in a non-contact manner.

On the other hand, the suction bridle 40 is arranged on the exit side of the water quench 80. This suction bridle 40
Has a pair of suction rolls 41. As shown in FIG. 3, the suction roll 41 has a hollow cylindrical shape, and a large number of suction ports 41a are formed on the outer peripheral surface thereof. One end of the suction roll 41 is connected to a rotary drive device (not shown), and the other end is connected to a vacuum pump (not shown) via a suction passage 42. The suction roll 41 is wider than the strip S. Therefore, when the strip S is wound around the pair of suction rolls 41 in an S-shape, the suction roll 41 is rotated, and the inside of the suction roll 41 is made a negative pressure by the vacuum pump, the strip S is sucked through the suction port 41a and the suction is performed. It will be attracted to the roll 41. Therefore, even if the strip S is wet with the cooling water W, slip does not occur between the suction roll 41 and the strip S, and a constant tension is generated in the strip S.
A back plate 43 is attached to a portion of the suction roll 41 where the strip S is not wound to enhance airtightness.

The pickling pretreatment apparatus of the present embodiment having the above configuration is used as follows.

First, the strip S is fed to the salt bath 10, immersed in the molten salt bath L, and passed through the plate. Here, the strip S is guided in a non-contact manner by the molten salt ejected from both salt floaters 11, and the molten salt L1 flows out equally from the gap between the strip S and the left and right centering guides 12 and is centered in the center thereof. Will be done. After that, hot air is blown from both sides of the strip S on the outlet side of the salt bath 10 by the air wiper 20 to blow off the adhering molten salt and reduce the film thickness. The blown-down molten salt is collected by the tray 16 and returned to the tank 14. Subsequently, when the strip S is wound around the floater 31, it is non-contact-turned by the jetting air and guided to the water quench 80. At this time, the same air flows out from the gap between the strip S and the left and right centering guides 32, and the strip S is centered in the center. Then, the strip S that has passed through the water quench 80 is wound around the pair of suction rolls 41. Since the suction roll 41 rotates and sucks from the suction port 41a, the strip S is brought into close contact with the suction roll. Therefore, even if the strip S is slippery by the cooling water W, it is in close contact with the suction roll 41 and slipping is completely prevented. At this time, the back plate 43 improves adhesion by minimizing suction of excess air.

The suction bridle 40 and upstream and downstream bridles (not shown) apply optimum tension to the strips S of the furnace section upstream of the suction bridle 40 and the tank section downstream thereof.

Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is arranged between the vertical heating furnace (not shown) and the cooling device 100 and the electrolytic pickling tank 90,
A semi-cylindrical salt floater 51 is internally provided in a salt bath 50 provided on the outlet side of the cooling device 100. The internal structure of this salt floater 51 is the same as that of the salt floater 11 of the first embodiment, and the same operational effect is obtained. The above
1, in the second embodiment, the salt floaters 11 and 51, the air wiper 2
Since 0 and the floater 31 and the strip S are not in contact with each other and the strip S is almost completely centered, it is possible to completely prevent the occurrence of scratches on the strip S and the traveling speed thereof is 100 to 200 m. It can be as fast as / min.

Next, the third and fourth embodiments of the present invention will be described with reference to FIGS.
It will be described with reference to the drawings. In the third embodiment, a rotatable deflector roll 32 is arranged in place of the floater 31 of the first embodiment, and in the fourth embodiment, the floater 31 of the second embodiment is replaced. Rotatable deflector roll 32
Is arranged.

The third and fourth embodiments are used when the strip S has a large thickness and it is difficult to float by air, or when the strip surface properties are not so severe.

<Effects of the Invention> The present invention has the following effects as specifically described above based on the embodiments.

(1) Since the salt floater is internally provided in the salt bath and the salt wiper and the direction changing means are arranged between the salt bath and the water quench, the contact with the strip is reduced and the occurrence of scratches is prevented. At the same time, even if the strip has a small plate thickness and a small tension, the centering of the strip is facilitated and the strip can be run at a high speed.

(2) By arranging the suction bridle on the outlet side of the water quench, it is possible to apply appropriate tensions to the strips of the upstream furnace section and the downstream tank section of the suction bridle, respectively.
The stripability of the strip in the pickling tank can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, FIG. 4, FIG. 5, and FIG.
1, 2nd, 3rd, 4th Embodiment of the pickling pretreatment apparatus, FIG. 2 is a sectional view of a salt bath and a floater, FIG. 3 is a sectional view of a suction bridle, and FIG. 7 is It is a block diagram of the conventional pickling pretreatment apparatus. In the drawing, 10,50 is a salt bath, 11,51 is a salt floater, 20 is an air wiper, 21 is a jet nozzle, 31 is a floater, 32 is a deflector roll, 40 is a suction bridle, 41 is a suction roll, and S is a strip. .

Claims (1)

[Claims] 1. A pickling pretreatment apparatus for a stainless steel strip, comprising a water quench located on the inlet side of a pickling tank, and a salt bath located on the inlet side of the water quench. In the bath, a salt floater for injecting molten salt to guide the stainless steel strip in a non-contact manner is internally provided, and an air wiper for blowing out the molten salt attached to the stainless steel strip with air is provided on the outlet side of the salt bath. Provided further, a direction changing means for the stainless steel strip is installed on the inlet side of the water quench, and a stainless steel strip is adsorbed on the outlet side of the water quench by negative pressure to give a certain tension to the stainless steel strip. A pickling pretreatment device, which is equipped with a suction bridle.