JP2012149295A - Device for removing foreign matter in snout and method for removing the foreign matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for removing foreign matter in a snout capable of manufacturing a high-quality plated steel plate in which surface defect is suppressed by discharging the foreign matter sticking on an inner wall surface of the snout to the outside of the snout.SOLUTION: The device for removing foreign matter in a snout is used for removing the foreign matter in the snout placed in a plating tank for hot-dip-plating a to-be-plated material, and includes a snout elevating and lowering device 6, a foreign matter peeling device 7 and a foreign matter sucking device 8. The snout elevating and lowering device 6 operates the snout 2 to move up and down when cleaning the inside of the snout 2, and positions the elevating/lowering position of the snout 2 at an arbitrary position. The foreign matter peeling device 7 peels the foreign matter sticking on the inner wall surface of the snout 2 when cleaning the inside of the snout 2, to clean the inner wall surface of the snout 2. The foreign matter sucking device 8 sucks the peeled foreign matter and the floating foreign matter on the plating bath surface in the snout 2 when cleaning the inside of the snout 2.

Description

  The present invention relates to a foreign matter removing apparatus in a snout for removing foreign matter in a snout installed in a plating tank for hot-plating a material to be plated and a method for removing the foreign matter.

Conventionally, as this kind of foreign substance removal apparatus in a snout, the thing of patent document 1 is known, for example.
This foreign matter removing device includes a swivelable guide vane that contacts the plating bath surface in the snout and stirs the plating bath, dross suction means for sucking dross that is a foreign matter floating in the plating bath, and the like.
Here, the foreign matter refers to metal oxides, intermetallic compounds, oxides of impurities, etc. that cause surface defects when they float on the plating bath surface of the plating tank and adhere to the surface of the material to be plated.
In such a foreign substance removing device, when the plating bath is agitated by swirling the guide vane and a flow occurs, the dross is sucked into the suction port of the dross suction means and discharged to the outside, so that the plating bath is a normal bath. It can recover to the surface state.

JP 2006-274414 A

  By the way, in the conventional apparatus, the foreign matter floating on the plating bath surface in the snout can be removed as described above. May give. As a case where a large amount of foreign matter is generated in a short time as described above, there is a case where the plating bath surface fluctuates. If foreign matter adheres to the part above the plating bath surface, if there is no change in the bath surface, it is unlikely that a large amount of foreign matter will be peeled off at one time. There is a risk of peeling. In order to avoid such problems, the plating bath surface of the plating tank is often adjusted so as not to fluctuate up and down during operation, but it is difficult to eliminate this fluctuation at all. In addition, when the bath surface fluctuation is suppressed as much as possible, there is a problem that a large amount of foreign matter adheres to a certain position. As described above, there is a problem that the foreign matter adhering above the bath surface is difficult to remove.

For this reason, when the plating bath surface fluctuates, the foreign matter adhering to the inner wall surface of the snout is peeled off, and a large amount of foreign matter floats on the plating bath surface in the snout in a short time. There exists a malfunction that a foreign material adheres to the to-be-plated material (steel plate) processed with a plating tank, and a surface defect arises.
Accordingly, the present invention provides a device for removing foreign matter in the snout, which can remove foreign matter adhering to the inner wall surface of the snout outside the snout and produce a high quality plated steel sheet with suppressed surface defects. There is to do.

In order to solve the above problems and achieve the above object, the present invention has the following configuration.
An apparatus of the present invention is a foreign matter removing device in a snout for removing foreign matter in a snout installed in a plating bath for hot-plating a material to be plated, which is above and below the snout with respect to the plating bath surface of the plating bath. Changing means for changing the height position, and discharging an inert gas from a discharge port disposed below the plating bath surface in the snout, and vibrating the plating bath surface to remove foreign matter adhering to the inner wall surface of the snout Foreign matter peeling means for peeling off, and foreign matter suction means for sucking foreign matter peeled off from the inner wall surface of the snout and foreign matter floating on the plating bath surface in the snout.

The changing means moves the snout up and down within a predetermined movement range from the operation position when cleaning the inside of the snout, and the movement range is a target value of the plating bath surface of the plating tank at the time of operation. It is larger than the allowable range.
Further, the changing means comprises a snout raising / lowering means for raising and lowering the snout from the operation position in the depth direction of the plating tank when cleaning the inside of the snout, and the snout raising / lowering means removes the snout when the snout is raised. The snout is positioned at the first position, and the snout is positioned at the second position when the snout is lowered.

  The method of the present invention is a method for removing foreign matter in a snout that removes foreign matter in a snout installed in a plating tank for hot-plating a material to be plated, wherein an inert gas is removed under the plating bath surface in the snout. Discharging, vibrating the plating bath surface to peel off foreign matter adhering to the inner wall surface of the snout, and sucking out the peeled foreign matter and foreign matter floating on the plating bath surface and discharging it out of the snout. A first step and a second step of moving the snout in the depth direction of the plating tank and changing the installation position of the snout after completion of the first step, the first step and the first step The foreign matter in the snout is removed by repeating the two steps.

As described above, in the present invention, at the time of cleaning the snout, for example, the snout is moved in the depth direction of the plating tank so that the installation position of the snout can be changed.
And after the change, the inert gas was discharged under the plating bath surface in a snout, the plating bath surface was vibrated, and the foreign material adhering to the inner wall surface of a snout was peeled off.
Further, the peeled foreign matter and the foreign matter floating on the plating bath surface in the snout are sucked and discharged out of the snout.
For this reason, according to the present invention, it is possible to remove the foreign matter adhering to the inner wall surface of the snout to the outside of the snout, and also to clean the inner wall surface of the snout, and to improve the quality with suppressed surface defects. A plated steel sheet can be manufactured.

It is a figure which shows the structure of embodiment of this invention. It is explanatory drawing explaining the state of the foreign material which generate | occur | produces in a snout. It is explanatory drawing explaining the removal method of the foreign material adhering to the inner wall face of a snout.

An embodiment of the foreign matter removing apparatus in the snout of the present invention will be described with reference to FIG.
(Device configuration)
The embodiment of the apparatus of the present invention is applied to a part of a continuous hot dip plating line, and as shown in FIG. 1, foreign matter existing in the snout 2 installed in the hot dip plating tank 1 is placed outside the snout 2. To be removed.

In this embodiment, as shown in FIG. 1, one end side of the snout 2 is connected to the smelting furnace 3, and the other end side of the snout 2 is disposed in the plating bath of the plating tank 1. The inside of the snout 2 is a hollow body so that the material to be plated a can be conveyed, and for example, its cross-sectional shape is rectangular. The snout 2 includes a bellows portion 2a that can be expanded and contracted on the upper side in order to move the snout 2 up and down by a snout elevating device 6 described later.
A roll 4 is disposed in the refrigeration furnace 3, and a roll 5 is disposed in the plating tank 1. And the two rolls 4 and 5 convey the to-be-plated material a in the smelting furnace 3 to the inside of the plating tank 1 through the inside of the snout 2, and then to the outside in the plating tank 1. It is supposed to let you.

Moreover, in this embodiment, in order to clean the inside of the snout 2, as shown in FIG. 1, the snout raising / lowering device 6, the foreign material peeling apparatus 7, and the foreign material suction apparatus 8 are provided.
When the inside of the snout 2 is cleaned, the snout lifting / lowering device 6 raises and lowers the snout 2 by moving the bellows part 2a of the snout 2 (up and down movement), and the raising / lowering position of the snout 2 is arbitrarily set. It is positioned at a position.

  The foreign matter peeling device 7 peels foreign matter adhering to the inner wall surface of the snout 2 when cleaning the inside of the snout 2, and cleans the inner wall surface of the snout 2. Specifically, a discharge pipe 9 is provided in the plating tank 1, and a discharge port (nozzle) 10 of the discharge pipe 9 is disposed below the plating bath surface in the snout 2. Then, by supplying an inert gas to the inlet of the discharge pipe 9, the inert gas is discharged (injected) from the discharge port 10 of the discharge pipe 9, and this discharge vibrates the plating bath surface in the snout 2, The foreign matter adhering to the inner wall surface of the snout 2 is peeled off by the impact of the vibration.

The foreign matter suction device 8 sucks the foreign matter peeled off from the inner wall surface of the snout 2 by the foreign matter peeling device 7 and the foreign matter floating on the plating bath surface in the snout 2 when cleaning the inside of the snout 2. Specifically, the suction pipe 12 is provided in the plating tank 1, and the suction port 11 of the suction pipe 12 is disposed on the plating bath surface in the snout 2. A suction pump 13 is provided in the middle of the suction pipe 12. Then, by operating the suction pump 13, the foreign matter peeled off from the inner wall surface of the snout 2 and the foreign matter floating on the plating bath surface in the snout 2 are sucked from the suction port 11 of the suction pipe 12. The foreign matter is discharged to the outside of the snout 2 through the suction pipe 12.
Furthermore, in this embodiment, during operation of the plating line, the level of the plating bath surface of the plating tank 1 is measured with the level meter 14 so that the plating bath surface level is within an allowable range centering on the target value. Supply control of the supply device 15 is performed.

(Foreign matter removal method)
Next, a method for removing the foreign matter generated in the snout 2 by using the embodiment shown in FIG. 1 will be described.
Prior to this description, foreign matter generated in the snout 2 during operation of the plating line will be described with reference to FIG. FIG. 2 is a sectional view of the snout 2.
As shown in FIG. 2, when the plating line is operated, the foreign matter c is in a state of being on the plating bath surface in the snout 2 and on the outer portion in the width direction of the material to be plated a. Further, a foreign substance b having a predetermined thickness adheres to a portion of the inner wall surface of the snout 2 that faces the plate surface of the material to be plated a.

  In this embodiment, as described above, the level of the plating bath surface 20 of the plating tank 1 is controlled to the target value during the operation of the plating line, but actually, the level changes to the upper limit based on the target value. It fluctuates in the range (allowable range) from the upper limit level to the lower limit level (see FIG. 3A). For this reason, during operation of the plating line, the foreign matter b adheres to the inner wall surface of the snout 2 in a relatively wide range in the height direction according to the variation of the plating bath surface 20.

Further, during the subsequent operation of the plating line, due to the fluctuation of the plating bath surface 20, the foreign matter b adhering to the inner wall surface of the snout 2 melts and adheres to the surface of the material to be plated a. There is a problem of causing surface defects.
Therefore, in this embodiment, the inside of the snout 2 is cleaned before the operation of the plating line is started, and the foreign matter generated in the snout 2 at the time of the previous operation of the plating line at this time is as shown in FIG. It peeled off and removed from the snout 2.

First, at the start of cleaning in the snout 2, as shown in FIG. 3A, the level 20 of the plating bath surface of the plating tank 1 is at the target value, and the inner wall surface of the snout 2 in the operation position is, for example, shown in the figure. In this way, the foreign matter b is attached.
In this state, the foreign substance peeling device 7 discharges (injects) the inert gas from the discharge port 10 of the discharge pipe 9 by supplying the inert gas to the inlet of the discharge pipe 9. By this discharge, the plating bath surface 20 is vibrated, and the foreign matter b adhering to the inner wall surface of the snout 2 is peeled off by the impact of the vibration at this time. The operation time of the foreign substance peeling device 7 is a time sufficient for the peeling.

  At this time, the foreign object suction device 8 is operated. For this reason, the foreign matter b peeled off from the inner wall surface of the snout 2 and the foreign matter c floating on the plating bath surface in the snout 2 are sucked into the suction port 11 of the suction pipe 12 by the suction pump 13 of the foreign matter suction device 8 and snout. 2 is discharged outside. At this time, all the foreign matter b adhering to the inner wall surface of the snout 2 is not peeled off, and, for example, the foreign matters b1 and b2 are left (see FIG. 2B).

  Next, as shown in FIG. 3 (B), the snout 2 is raised by the snout elevating device 6 and then positioned. At this time, the ascent distance (increase value) H from the operation position which is the reference position of the snout 2 is set to a value larger than the allowable value B on the lower limit level side of the target value of the plating bath surface 20 of the plating tank 1. . This is because, as described above, the width in the length direction of the snout 2 of the foreign matter c1 adhering to the inner wall surface of the snout 2 may be larger than the allowable range of the plating bath surface 20 of the plating tank 1 in some cases. Therefore (see FIG. 3A), this is because the foreign matter b in the protruding portion is effectively peeled off.

Then, the foreign matter peeling device 7 is operated for a predetermined time with the snout 2 positioned, and at this time, the foreign matter b1 remaining without being peeled from the inner wall surface of the snout 2 is peeled, and the inner wall surface is cleaned. The separated foreign matter b1 and the foreign matter floating on the plating bath surface in the snout 2 are sucked by the foreign matter suction device 8 and discharged out of the snout 2.
Subsequently, as shown in FIG. 3C, the snout 2 is moved down by the snout elevating device 6 and then positioned. The descending distance (falling value) L from the reference position of the snout 2 at this time is set to a value larger than the allowable value A on the upper limit level side of the target value of the level of the plating bath surface 20 of the plating tank 1. The reason for this is the same as in the case where the snout 2 is raised.

Then, the foreign matter peeling device 7 is operated for a predetermined time with the snout 2 positioned, and at this time, the foreign matter b2 remaining without being peeled from the inner wall surface of the snout 2 is peeled to clean the inner wall surface. The peeled foreign matter b2 and the foreign matter floating on the plating bath surface in the snout 2 are sucked by the foreign matter suction device 8 and discharged out of the snout 2.
Thereafter, when the snout 2 is lifted from the position shown in FIG. 3C to the position shown in FIG. 3D by the snout elevating device 6 to the operation position which is a predetermined position, the foreign matter adhered to the inner wall surface of the snout 2 is All are removed and the inner wall surface of the snout 2 is cleaned in a wide range, and a new operation can be performed in this state.

(Effect of embodiment)
As described above, in this embodiment, when the inside of the snout 2 is cleaned, the snout lifting device 6 raises and lowers the snout 2 from the reference position, and the distance (moving distance) that can be raised and lowered is the plating tank 1. The plating bath surface 20 was set to be larger than the allowable range of the target value of the level. In addition, the snout 2 can be positioned at each position when moving up and down.

In this embodiment, when cleaning the inside of the snout 2, the foreign substance peeling device 7 discharges an inert gas below the plating bath surface in the snout 2, thereby vibrating the plating bath surface to cause the inside of the snout 2. The foreign matter adhering to the wall surface was peeled off, and the inner wall surface of the snout 2 was cleaned.
Furthermore, in this embodiment, when cleaning the inside of the snout 2, the foreign matter suction device 8 is separated from the inner wall surface of the snout 2 and floats on the plating bath surface in the snout 2, and the plating bath surface in the snout 2. Each foreign substance already floating above was sucked and discharged out of the snout 2.

Moreover, the inert gas discharged from the foreign material peeling apparatus 7 is not particularly limited, and examples thereof include a rare gas group such as argon, nitrogen having low chemical reactivity, and the like.
Therefore, according to this embodiment, it is possible to remove foreign matter or the like adhering to the inner wall surface of the snout 2 to the outside of the snout 2, and to clean the inner wall surface of the snout 2, thereby suppressing surface defects. High quality plated steel sheet can be manufactured.

(Other embodiments)
(1) In the above-described embodiment, when the inside of the snout 2 is cleaned, the snout lifting / lowering device 6 raises and lowers the snout 2 from the reference position, and the installation position of the snout 2 is changed.
However, instead of this, at the time of cleaning the inside of the snout 2, the installation position of the snout 2 is left at the reference position, and the height of the plating bath surface of the plating tank 1 is used around the reference level of the plating bath surface. May be raised and lowered.

(2) In the above embodiment, when cleaning the inside of the snout 2, the snout lifting device 6 lifts and lowers the snout 2 from the operating position, and the foreign matter peeling device 7 and the foreign matter suction device 8 are operated in this positioned state. I did it.
However, instead of this, the foreign matter peeling device 7 and the foreign matter suction device 8 may be operated in the process in which the snout lifting device 6 lifts and lowers the snout 2 when cleaning the inside of the snout 2.

a ... material to be plated b, b1, b2, c ... foreign matter 1 ... plating tank 2 ... snout 3 ... smelting furnace 4, 5 ... roll 6 ... snout lifting device 7 ... Foreign matter peeling device 8 ... Foreign matter suction device 9 ... Discharge pipe 10 ... Discharge port 11 ... Suction port 12 ... Suction pipe 13 ... Suction pump 20 ... Plating bath surface

Claims (4)

A foreign matter removing device in a snout for removing foreign matter in a snout installed in a plating tank for hot-plating a material to be plated,
Change means for changing the vertical position of the snout with respect to the plating bath surface of the plating tank;
Foreign matter peeling means for discharging an inert gas from a discharge port disposed below the plating bath surface in the snout, and vibrating the plating bath surface to remove foreign matter adhering to the inner wall surface of the snout,
Foreign matter suction means for sucking foreign matter peeled off from the inner wall surface of the snout and foreign matter floating on the plating bath surface in the snout,
An apparatus for removing foreign matter in a snout, comprising: The changing means moves the snout up and down within a predetermined movement range from the operation position when cleaning the inside of the snout,
The foreign matter removing device in a snout according to claim 1, wherein the moving range is larger than an allowable range of a target value of a plating bath surface of the plating tank during operation. The changing means comprises a snout raising / lowering means for raising and lowering the snout from the operation position in the depth direction of the plating tank when cleaning the inside of the snout,
3. The snout lifting / lowering means positions the snout at a first position when the snout is raised, and positions the snout at a second position when the snout is lowered. The foreign matter removing device in the snout as described in 1. A foreign matter removal method in a snout for removing foreign matter in a snout installed in a plating tank for hot-plating a material to be plated,
An inert gas is discharged under the plating bath surface in the snout, the foreign matter adhering to the inner wall surface of the snout is peeled by vibrating the plating bath surface, and the separated foreign matter and the plating bath surface are floated on the plating bath surface. A first step of sucking out foreign matter to be discharged and discharging it out of the snout;
After the completion of the first step, the second step of moving the snout in the depth direction of the plating tank and changing the installation position of the snout,
A foreign matter removal method in a snout, wherein the foreign matter in the snout is removed by repeating the first step and the second step.

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