JP2004010987A - Seal box in continuous hot dip coating line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal box capable of lowering an oxygen concentration in a seal box so as not to damage the appearance of a plating surface texture. <P>SOLUTION: The seal box is provided so as to simultaneously cover a steel belt, a gas wipping nozzle and a nozzle header at the upper side of a plating bath, and a nozzle header holes being long vertically are provided at the opposite side walls of a seal box main body at certain intervals in a front and rear direction, and both ends of the nozzle header are projected to the outside of the seal box and bellows are provided between the nozzle header holes. Sliding guides are provided at the upper end of the opposite side walls of the seal box main body, and a pair of top boards clamping a steel plate are supported slidably by right and left direction to the sliding guides, and a throat part surrounding the steel plate while narrowing the distance over suitable length is provided at the part clamping the steel plate of the top boards, and a seal nozzle ejecting a non-oxidative gas such as nitrogen in the diagonally upward direction of the steel plate is provided at the inside of the throat part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
The present invention relates to a seal box in a continuous hot-dip plating line.
[0002]
2. Description of the Related Art In a continuous hot-dip plating line, a gas wiping nozzle for controlling a predetermined amount of plating is provided at a rising portion of a steel strip from a plating bath. Generally, non-oxidizing gas such as compressed air, combustion exhaust gas, or nitrogen is used as the gas fluid of the nozzle. However, a non-oxidizing gas such as nitrogen is used depending on the type of plating and the amount of adhesion to improve the appearance of the steel strip plating surface. In this case, a seal box is installed immediately above the plating bath, and gas wiping is performed in the box. At this time, wiping while keeping the oxygen concentration in the seal box low makes the appearance of the surface better, so it is necessary to produce while keeping the oxygen concentration in the seal box as much as possible.
[0003]
However, the conventional seal box has a gas wiping nozzle header (having a vertical movement of approximately 600 mm stroke, an opening and closing operation of approximately 100 mm stroke on one side, and a rotation operation corresponding to an arbitrary nozzle angle). And the opening remained, and it was difficult to maintain good sealing properties. In addition, in the conventional seal box, air outside the seal box enters into the inside of the seal box through a slit passing through the steel plate on the upper surface of the seal box, etc., and the oxygen concentration in the seal box increases, which may impair the appearance of the plating surface. Was. When an AJC (air jet cooler) is provided at the upper portion for forced cooling of the steel sheet, the oxygen concentration in the seal box is more likely to increase due to the intrusion of the air.
An object of the present invention is to solve the above-mentioned problems and to provide a seal box that keeps the oxygen concentration in the seal box low so as not to impair the appearance of the plating surface.
[0004]
Means for Solving the Problems In order to solve the above problems, the constitution of the present invention is as follows. That is, the first configuration is configured such that the steel strip guided by the sink roll installed in the plating solution in the plating bath is introduced obliquely downward from above and led out upward, and the steel strip is drawn directly above the liquid level. A seal box is provided so that the nozzle header, which can move up and down, can move back and forth, and is rotatable across the band, and the gas wiping nozzle face each other, and simultaneously cover the steel strip, the gas wiping nozzle, and the nozzle header. In the seal box, the main body of the seal box has a rectangular cylindrical shape, and vertically long nozzle header holes are provided on front and rear side walls of the main body at an interval in front and rear, and penetrate through these nozzle header holes. The both ends of the nozzle header protrude outside the seal box and are supported at the ends, and a bellows is provided between the nozzle header and the nozzle header except for the end of the nozzle header. Is that which is provided.
[0005]
In the second configuration, in addition to the first configuration, in the seal box, sliding guides are provided at upper ends of opposed side walls of the main body, and the sliding guides are provided on a pair of ceilings sandwiching the steel plate. A plate is slidably supported in the left-right direction, and a throat portion that surrounds the steel plate at an appropriate length is formed at a portion of the top plate sandwiching the steel plate. Means that a seal nozzle for ejecting a non-oxidizing gas such as nitrogen in an obliquely upward direction is provided on the steel plate.
[0006]
A third configuration is that, in addition to the first or second configuration, a seal cloth that seals a space between the molten metal surface and the molten metal surface is provided at a lower portion of the seal box body.
[0007]
In a fourth configuration, in addition to the first, second, or third configuration, a curtain hoisting shaft is provided on one of the front and rear walls of the seal box main body, and a seal curtain is provided on the hoisting shaft. Is wound so that its lower end seals with the surface of the molten metal.
[0008]
A fifth configuration is that, in addition to the first, second, third or fourth configuration, the seal box is provided with a non-oxidizing gas injection pipe for adjusting the oxygen concentration in the box.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described based on an embodiment shown in the drawings.
The seal box B of a continuous galvanizing line shown in FIGS. 1, 2, 3, strip A guided to the sink roll P ₂ installed in the plating solution within the plating bath P ₁ is introduced obliquely from top to bottom And is derived upward. Then, across the steel strip A immediately above the liquid surface, vertically movable, the front and rear movable, and the nozzle header P ₃ and the gas wiping nozzle P ₄ with turnable faces. A seal box B is provided so as to simultaneously cover the steel strip, the gas wiping nozzle, and the nozzle header.
[0010]
3 and 4, the main body 1 of the seal box has a rectangular cylindrical shape, and vertically long nozzle header holes 1a are provided on front and rear side walls of the main body at intervals. Both ends of the nozzle header P ₃ passing through these nozzle headers hole is supported at the end protruding to the outside of the seal box. Heat-resistant glass windows 1b, 1b which can be opened and closed vertically are provided between the nozzle header holes 1a, 1a, and are used for internal monitoring and nozzle interval measurement.
[0011]
Well here, except for the end portion of the nozzle header P _3, between the nozzle header holes 1a, the bellows 5 is provided. This bellows is made of a heat-resistant cloth (for example, silicon glass cloth) having excellent resistance to molten metal erosion and poor wettability to molten metal. In the seal box B, sliding guides 3 are provided at the upper ends of the opposing side walls of the main body 1, and these sliding guides include a pair of top plates 2 sandwiching the steel plate A. It is slidably supported in the left-right direction.
[0012]
A throat portion 4 that surrounds the steel plate A at a suitable length is formed at a portion of the top plate that sandwiches the steel plate A with a suitable length. Inside the throat portion 4, a seal nozzle 4a is provided, which uniformly sprays a non-oxidizing gas such as nitrogen in the width direction of the steel plate and has a nozzle angle adjustable, and a seal plate 4b is provided above the seal nozzle 4a. Provided. These prevent air from entering from above the seal box.
[0013]
A seal cloth 6 (made of, for example, a bulky glass fiber cloth) is provided at the lower portion of the seal box body 1 to seal the gap between the molten metal level and the molten metal level. A curtain hoisting shaft 7a is provided on the upper part of the front wall (the left side in FIG. 1) of the seal box main body 1, and a seal curtain 7b is wound around the hoisting shaft. It is made to seal between. This curtain (the material is, for example, a bulky glass fiber cloth) is wound up when the dross in the box is discharged. The seal box is provided with a non-oxidizing gas blowing pipe 8 and a sampling pipe 9 for adjusting the oxygen concentration in the box. The atmospheric gas in the seal box collected from the sampling pipe is sent to an oxygen concentration measuring device, and the non-oxidizing gas flow rate is increased or decreased according to the oxygen concentration, and is blown into the seal box from the blow-in pipe 8.
[0014]
In the above, when the nozzle header P ₃ (elevating / lowering operation of approximately 600 mm stroke / opening / closing operation of approximately 100 mm stroke on one side) and the gas wiping nozzle P ₄ (having a rotation operation corresponding to an arbitrary nozzle angle) perform the position changing operation. Since the bellows 5 is provided between the nozzle and the nozzle header hole 1a, good sealing performance can be maintained.
[0015]
Further, sliding guides 3 are provided at the upper ends of the opposed side walls of the main body 1, and a pair of top plates 2 sandwiching the steel plate A are slidable in the left and right directions on these sliding guides. Supported by Therefore, the gap between the steel plate passing slits on the upper surface of the seal box can be appropriately adjusted, and the intrusion of air from outside the seal box can be prevented. In addition, a sealing action by the throat portion 4 is added, and an increase in the oxygen concentration in the seal box can be further suppressed.
[0016]
The present invention is not limited to the examples and embodiments described above, but includes various modifications without departing from the spirit and scope of the claims.
[0017]
【The invention's effect】
According to the configuration of the present invention, good sealing properties can be maintained for the seal box, the oxygen concentration in the seal box can be kept low, and the appearance of the plating surface can be prevented from being impaired.
[Brief description of the drawings]
FIG. 1 is a side view of one embodiment of the present invention.
FIG. 2 is a front view of one embodiment of the present invention.
FIG. 3 is a plan view of one embodiment of the present invention.
FIG. 4 is a perspective view of a main part of one embodiment of the present invention.
[Explanation of symbols]
A Steel strip B Seal box P ₁ Plating bath P ₂ Sink roll P ₃ Nozzle header P ₄ Gas wiping nozzle 1 Seal box body 1a Nozzle header hole 1b Window 2 Seal box top plate 3 Top plate sliding guide 4 Throat portion 4a Seal nozzle 4b Seal plate 5 Bellows 6 Seal cloth 7a Curtain winding shaft 7b Seal curtain 8 Blow-in pipe 9 Sampling pipe

Claims (5)

The steel strip guided by the sink roll installed in the plating solution in the plating bath is configured to be introduced downward from diagonally above and led out upward.The steel strip can be raised and lowered with the steel strip directly above the liquid level , A front and rear movable and rotatable nozzle header and a gas wiping nozzle are opposed to each other, and a seal box is provided so as to simultaneously cover the steel strip, the gas wiping nozzle and the nozzle header,
The main body of the seal box has a rectangular cylindrical shape, and vertically long nozzle header holes are provided at intervals in front and rear on opposite side walls of the main body, and the nozzle header penetrating these nozzle header holes is provided. Seal box in a continuous hot-dip plating line characterized in that both ends of the seal box protrude outside the seal box and are supported at the ends, and bellows are provided between the nozzle header holes except for the end of the nozzle header. . In the seal box, sliding guides are provided at upper ends of opposed side walls of the main body, and a pair of top plates sandwiching the steel plate are slidably supported in the left and right directions by these sliding guides. A throat portion is formed in a portion of the top plate that sandwiches the steel plate, the throat portion surrounding the steel plate at an appropriate length with a small interval therebetween, and inside the throat portion, a nitrogen or the like is obliquely upwardly attached to the steel plate. The seal box in the continuous hot-dip plating line according to claim 1, further comprising a seal nozzle for jetting the non-oxidizing gas. The seal box in a continuous hot-dip plating line according to claim 1, wherein a seal cloth for sealing between a molten metal surface and a molten metal surface is provided at a lower portion of the seal box main body. A curtain hoisting shaft is provided on the upper part of one of the front and rear walls of the seal box main body, and a seal curtain is wound around the hoisting shaft so that the lower end seals with the molten metal surface. The seal box in a continuous hot-dip plating line according to claim 1, wherein the seal box is provided. The seal box in the continuous hot-dip plating line according to claim 1, wherein a non-oxidizing gas blowing pipe for adjusting an oxygen concentration in the box is provided in the seal box.

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