JPH09263980A - Rotary seal method of strip such as steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary sealing method capable of preventing generation of surface flaws or wrinkles of a strip while leakage of the treatment solution is prevented to a maximum. SOLUTION: In an equipment in which a strip S is passed between a pair of seal rolls 2, 3 provided on at least either of the inlet side and the outlet side of a treatment tank 1 to continuously pass the strip S, the gap between the circumferential surfaces of a pair of sealing rolls 2, 3 is set to be larger than the thickness of the strip by 0.3-2mm to realize the non-contact relationship between the strip surface and the circumferential surfaces of the sealing rolls, the treatment solution is squeezed by the space which is formed by the seal rolls and gradually reduced in the advancing direction of the strip, and a thin film layer made by the treatment solution in the treatment tank is formed between the strip surface and the circumferential surfaces of the sealing rolls to generate the sealing force to the treatment solution. The seal rolls are of the rotary type, and generation of surface flaws is controlled even when the strip is brought into contact with the sealing rolls by matching the rotational direction of the sealing rolls with the strip passing direction, and agreeing the peripheral speed of the sealing rolls with the strip passing speed to set the relative speed to be zero.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary sealing method for sealing a treatment liquid in a treatment tank for pickling or plating in the production of steel sheet without causing scratches on the surface of the steel sheet strip.

[0002]

2. Description of the Related Art In a treatment tank for continuously picking up a strip of steel sheet for pickling and plating, in the case of passing the strip vertically, the strip penetrates the lower end of the bath body. Since the vehicle travels, it is necessary to seal this penetrating portion to prevent the processing liquid from leaking. And since the strip is always running, the treatment liquid often leaks even as an accompanying flow along the surface of this strip,
Also in this case, it is necessary to prevent the leak of the processing liquid.

As a seal for preventing such a leak of the processing liquid, a pair of dam rolls are rotatably arranged with a pass line interposed therebetween as described in, for example, Japanese Patent Application Laid-Open No. 5-331695. There is a configuration in which both ends of the dam roll in the axial direction are sealed to the outside by seal rings, and seal plates for contacting and sealing the peripheral surface of the dam roll are arranged.

The seal device described in this publication is based on a conventionally known rotary seal.
By adding a seal ring and a seal plate, a more suitable seal function can be achieved.

[0005]

As for the pair of dam rolls in the above publication, similarly to the conventional rotary seal, the rotatable roll is butted against both sides of the strip and the strip is passed through while pressing the strip narrowly. It is going. Then, the sealing force for the strip surface can be increased almost in proportion to the narrow pressure between the rolls.

However, in the case where the strip surface is narrowed by such a pair of rolls, the strip surface tends to be damaged. This is because in the case of sludge or electrolysis tank, the treatment liquid contains foreign substances such as electrodeposits, and these foreign substances may get caught between the strip surface and the roll. This is one cause. When the strip surface is scratched in this way, the quality of the strip is significantly deteriorated, so that the frequency of inspection and replacement of the sealing roll is increased, which also affects the operation rate of the line.

Further, when the strip is in a meandering state and goes out of the sealing roll, the strip is squeezed in the axial direction of the roll because the strip is narrowed between the rolls. The strip in the pressed portion is passed without any degree of freedom in the thrust direction of the roll. Therefore,
As the strip passes between the rolls, the thrust force received from the rolls in the meandering direction is intricately entangled with each other, resulting in wrinkles on the strip, which is similar to the case of surface scratches caused by foreign matter. Will significantly deteriorate the quality of.

Further, not only when foreign matter is caught, but also when the strip is in contact with the roll peripheral surface, the surface of the strip is scratched. This is partly because the narrow pressure on the strip of the roll is kept high in order to secure the sealing pressure, but the same applies when the strip passing speed and the roll peripheral speed do not match. Phenomenon occurs.

As described above, in the conventional treatment tank for pickling or plating, since the sealing roll is abutted against the surface of the strip, there is a problem that surface scratches and wrinkles cannot be avoided.

The problem to be solved in the present invention is to provide a rotary sealing method capable of preventing the surface scratches and wrinkles of the strip while maximizing the prevention of leakage of the processing liquid.

[0011]

DISCLOSURE OF THE INVENTION The present invention provides a facility for passing a strip between a pair of seal rolls provided on at least one of an inlet side and an outlet side of a processing tank for continuously passing the strip, wherein The distance between the peripheral surfaces of the seal roll is set to be 0.3 to 2 mm larger than the plate thickness of the strip so that the surface of the strip and the peripheral surface of the seal roll are in a non-contact relationship, The treatment liquid is squeezed in a gradually decreasing space formed by the seal roll, and a thin film layer of the treatment liquid in the treatment tank is formed between the surface of these strips and the peripheral surface of the seal roll to form the treatment liquid. It is characterized by generating a sealing force against.

In such a method, the seal roll may be driven to rotate so that the rotation direction is aligned with the strip passage direction and the peripheral speed of the seal roll is matched with the strip passage speed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, while adequately exhibiting a sealing property that can be endured as a practical technique, a proper gap is provided between the strip surface and the peripheral surface of the seal roll so that the strip surface is not scratched. It is intended to provide a space. In determining the interval, the present inventors obtained data as shown in FIG. 1 as a result of an experiment on the relationship between the strip plate thickness, the outflow amount of the seal roll peripheral surface interval, and the occurrence frequency of scratches on the strip surface. I was able to.

As can be seen from this figure, even if the seal roll is not in contact with the strip surface, the interval is 0.3 to 2 mm larger than the plate thickness, preferably 0.5 to 1 m.
If the range is made larger, the accompanying flow generated by the strip passing plate is narrowed between the seal rolls by the gradually decreasing space formed by the seal rolls in the traveling direction of the strip. That is, the flow path resistance increases and the outflow of the processing liquid can be suppressed.

Further, as will be apparent from FIG. 2 which will be shown as an example to be described later, as for the interval of the peripheral surface of the seal roll, when the interval is small, the outflow amount of the processing liquid is small, but the occurrence frequency of scratches on the strip surface is small. To increase. On the other hand, when the distance is large, the frequency of occurrence of scratches on the strip surface is reduced, but the outflow of the treatment liquid is increased.

Therefore, in the present invention, from the relationship between the frequency of scratches on the strip surface and the clearance, the frequency of scratches on the strip surface is high in the range of 0.3 mm or less, so the minimum clearance is set to 0.3 mm. . Further, from the relationship between the processing liquid outflow amount and the clearance, if the clearance is 2 mm or more, the processing liquid outflow amount is large and it is not practical.
And

By setting the maximum and minimum values of such a gap, a thin film can be formed in the gap between the strip and the peripheral surface of the seal roll closest to the strip, and by using this thin film. It is possible to provide resistance to leakage of the processing liquid in the processing tank. Further, by rotating the seal roll, formation of a liquid film on the surface of the seal roll is further promoted.

On the other hand, due to the gap between the strip and the seal roll, even if foreign matter in the processing liquid enters, there is no biting, so that the surface of the strip can be prevented from being scratched.
Further, since there is no restraint in the thrust direction by the seal roll, wrinkles do not occur even if the strip sways in the width direction.

Further, when the seal roll is rotationally driven at a peripheral speed corresponding to the traveling speed of the strip, the relative speed between the peripheral surface of the seal roll and the strip surface becomes zero, and even if the seal roll comes into contact with the strip, the surface of the strip is damaged. Is prevented from occurring.

[0020]

FIG. 2 is a vertical cross-sectional view of an essential part showing a seal structure to which the rotary sealing method of the present invention is applied.

In the figure, for example, an inlet 1a for the strip S is provided at the lower end of the processing tank 1 for pickling or plating.
And a pair of seal rolls 2 and 3 for preventing the leakage of the processing liquid from the inlet 1a together with the strip S are provided on the lower surface of the processing tank 1. The seal rolls 2 and 3 are housed in a dedicated chamber provided on the lower surface of the processing tank 1 as described in, for example, JP-A-5-331695 mentioned in the section of the prior art, and the axial direction thereof. A seal ring may be provided on the end face of the device between the inner wall of the chamber and the seal ring. And a pair of sealing materials 1
By attaching b and 1c to the treatment tank 1 and contacting these sealing materials 1b and 1c to rotate the seal rolls 2 and 3, the seal rolls 2 and 3 and the bottom wall of the treatment tank 1 The space between them is sealed.

The seal rolls 2 and 3 are swung around the fulcrums 2a and 3a as shown by the solid line, the broken line and the chain double-dashed line, respectively, so that their positions can be changed. A drive mechanism such as an electric motor is connected to the seal rolls 2 and 3 so that the seal rolls 2 and 3 can be rotationally driven at a peripheral speed matching the traveling speed of the strip S, and an operation independent of the drive mechanism. By means of the means, the connection with the drive mechanism is released to allow free rotation.

The traveling direction of the strip S may be upward or downward in the figure, and when traveling upward, the seal rolls 2 and 3 are rotationally driven in the direction of the solid line arrow in the figure and when traveling downward, in the direction of the alternate long and short dash line. To be done.

Here, when the seal rolls 2 and 3 are at the positions indicated by the solid lines, the seal rolls 2 and 3 are arranged so as to have a gap with respect to the strip S. That is, the gap distance d on the line segment passing through the respective centers of the seal rolls 2 and 3 is equal to the plate thickness t of the strip S + (0.3 to
2) mm. As a matter of course, the gap distance d varies depending on the plate thickness of the strip S, and the larger the plate thickness, the larger the distance d. Therefore, a suitable value is set according to the conditions such as the plate thickness.

The setting of the distance d between the seal rolls 2 and 3 is based on the premise that the sealing property is sufficient to withstand practical technology. Is inevitable. On the other hand, for example, when the strip S travels upward in the figure, the seal rolls 2 and 3 rotate in the direction of the arrow shown by the solid line in the figure, so that the treatment liquid from the inlet 1a flows down along the surface of the strip S. Even if it does, it comes into contact with the peripheral surfaces of the seal rolls 2 and 3 and is pushed back upward, and it is possible to exert a resistance against the processing liquid leaking out through the gap as it is. In addition, the seal rolls 2 and 3 are provided on the upper end of the processing tank 1.
In the case of arranging,
In this case, the treatment liquid tends to rise as an accompanying flow attached to the surface of the strip S, but the self-weight of the treatment liquid itself suppresses leakage toward the upper side.

As described above, even if the seal rolls 2 and 3 are not in contact with the surface of the strip S and the pressure is narrowed, the leakage of the treatment liquid can be achieved by utilizing the rotation of the seal rolls 2 and 3 and the self-weight of the treatment liquid. Can be prevented to some extent.

Further, in the present invention, if the relationship between the viscosity of the treatment liquid and the distance between the seal rolls 2 and 3 and the surface of the strip S is appropriate, the treatment liquid is applied to the surface of the strip S where the distance is the narrowest. To form a thin film of. This is intended to utilize the same phenomenon as formation of a lubricating boundary layer film of lubricating oil in the field of lubrication.

Further, the seal rolls 2 and 3 are attached to the strip S.
By forming the liquid film on the surfaces of the seal rolls 2 and 3 by adjusting the rotation direction to the strip passing direction and further matching the peripheral speed of the seal rolls 2 and 3 to the strip passing speed of the strip S.

As described above, even if the seal rolls 2 and 3 do not squeeze the strip S, if the clearance is appropriate, the wake flow generated by the strip S passage is generated between the seal rolls 2 and 3. By making use of the fact that the flow path resistance is increased by narrowing down with and the formation of a thin film of the processing liquid is used, a seal drop that can be endured as a practical technique can be exhibited, and the desired processing by the processing tank 1 can be performed. Can be executed.

The rotary sealing method of the present invention has an important significance in that it can prevent the surface of the strip S from being scratched and wrinkled while having a certain sealing effect. That is, since the strips S do not come into contact with the seal rolls 2 and 3, even if foreign matter is contained in the treatment liquid and enters into the space between the strip S and the seal rolls 2 and 3, it is not caught. The occurrence of surface scratches on the strip S is prevented. Then, the seal rolls 2 and 3 themselves also rotate to remove the strip S from the seal materials 1b and 1c.
Since the treatment liquid adheres in a thin film form to the peripheral surface extending to the side, even if the strip S comes into contact with the seal rolls 2 and 3, the occurrence of surface scratches is similarly prevented.

Further, the strip S is composed of seal rolls 2 and 3.
Since the strip S passes through without being narrowed by the seal, even if the strip S swings in the axial direction of the seal rolls 2 and 3, the force for restraining the strip S in the width direction does not act. The formation of wrinkles in the thrust direction due to the rolls 2 and 3 is also prevented.

Further, the seal rolls 2 and 3 are of a system in which they are rotationally driven, and the seal rolls 2 and 3 are in the same direction as the running direction of the strip S and have a peripheral speed that matches the running speed. If the strip S is rotated, the relative speed between the strip S and the peripheral surfaces of the seal rolls 2 and 3 can be made zero. Therefore, the seal rolls 2, 3
Even if the strips S collide violently with each other, the mutual slippage does not occur, so that the occurrence of surface scratches can be prevented more effectively.

As described above, according to the present invention, it is possible to achieve the maximum task of surely preventing the surface scratches and wrinkles of the strip S from occurring while ensuring the sealing property of the treatment liquid which is necessary in practical technology. Is. For example, in the case where strips S are continuously passed through these treatment tanks in equipment in which a plurality of treatment tanks are arranged, the strips pass between a large number of seal rolls. And the shape is maintained well and high quality product can be obtained.

In this embodiment, the case where the strip S is passed through in the vertical direction has been described, but the present invention is not limited to this, and is also applied when the strip S is passed through in the lateral direction. Can be done.

[0035]

As described above, according to the present invention, the strip can be passed through while maintaining the maximum seal by positively utilizing the formation of a thin film without squeezing the strip by the seal roll. Since there is no such biting and there is no restraint in the thrust direction by the seal roll, it is possible to reliably prevent surface scratches and wrinkles on the strip.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship among a strip plate thickness, a seal roll peripheral surface interval liquid outflow amount, and a frequency of occurrence of scratches on a strip surface.

FIG. 2 is a schematic vertical cross-sectional view of a main part showing sealing of a strip by a seal roll to which the rotary sealing method of the present invention is applied.

[Explanation of symbols]

 1: Processing tank 1a: Inlet port 1b: Sealing material 2: Seal roll 2a: Support point 3: Seal roll 3a: Support point S: Strip

Claims (2)

[Claims] 1. In a facility for passing the strip between a pair of seal rolls provided on at least one of an inlet side and an outlet side of a treatment tank for continuously passing the strip, in a facility between the peripheral surfaces of the pair of seal rolls. The thickness of the strip is set to be 0.3 to 2 mm larger than that of the strip so that the surface of the strip and the peripheral surface of the seal roll do not contact each other, and the tape is gradually reduced in the traveling direction of the strip. A steel plate that squeezes the treatment liquid in the space where it is formed and forms a thin film layer of the treatment liquid in the treatment tank between the surface of these strips and the peripheral surface of the seal roll to generate a sealing force against the treatment liquid. Method for rotary sealing of strips. 2. The strip of a steel plate or the like according to claim 1, wherein the seal roll is of a rotary drive type so that the direction of rotation is aligned with the strip passing direction and the peripheral speed of the seal roll is matched with the strip passing speed. Rotary seal method.