KR101416774B1 - Gas wiping device - Google Patents

Abstract

The present invention relates to a gas wiping apparatus having a gas wiping nozzle for spraying a gas onto the surface of a steel strip to adjust an amount of deposition of molten metal for plating adhered to the surface of the steel strip to suppress overcoating or splashing at the widthwise ends of the steel strip Thereby providing an excellent gas wiping device. The gas-wiping nozzle (1) is provided with a slit (1a ') extending in the width direction of the steel strip (K) for ejecting gas from the hollow and a gas inlet (1e) for introducing gas into the hollow The left and right closure members 2 and 2 which are capable of slidably closing the right and left regions are disposed in the slit 1a ' And left and right rectifying elements (not shown) extending from the gas outlet side end portions 2a and 2a of the left and right closing members 2 and 2 to the partition wall 1d 1c and 1c are disposed on the right side and the gas flow paths GR are formed between the right and left rectifying pieces 1c and 1c and the width of the gas discharge port 1a and the width of the gas flow path GR are the same Gas wiping device (10).

Description

Gas wiping device

The present invention relates to a gas wiping device which adjusts the amount of molten metal to be plated adhered to a surface of a steel strip continuously fed and immersed in a plating bath.

So-called gas wiping is generally performed in which when the molten metal is plated by continuously immersing the steel strip in the molten metal plating bath, the deposited amount of the molten metal is adjusted by spraying gas onto the uncoated plated surface of the steel strip after immersion, For example, gas wiping is performed by disposing a gas wiping device having gas wiping nozzles on both sides of a continuously transported steel strip and spraying gas to both sides of the steel strip.

The gas wiping nozzle is immersed in the molten metal of the plating port and has a slender shape corresponding to the widthwise length of the steel strip which is transported upward in front of the molten metal so that gas is spouted along the width direction A gas-liquid separator is formed. Gas is sprayed straightly from one end in the width direction to the other end of the steel spout from the gas spouting port to wipe off the molten metal on the surface of the steel strip as much as necessary to adjust the amount of deposition.

However, in the above-mentioned gas wiping, there is a problem of overcoating in which the amount of adhered molten metal at both ends in the direction of the width of the steel is greater than that of other portions, and splashing in which molten metal wiped out by gas is scattered at both ends. Such a problem of overcoating or splashing is caused by turbulence caused by collision of gases discharged from opposing gas wiping nozzles in the vicinity of both ends of the steel strip.

In order to reduce overcoating and splashing at both end portions in the width direction of the steel strip, Patent Document 1 discloses a slit closing mechanism for making both ends positions of slits of both nozzles of a pair of opposed nozzles variable, And a mechanism for adjusting the gas flow rate so that the discharge flow rate of the nozzle becomes constant.

According to this gas wiping apparatus, by adjusting the positions of both ends of both slits of the pair of nozzles opposed to each other with the pulley interposed therebetween, the airflows from the opposed nozzles do not vigorously collide with each other, It is possible to eliminate the turbulence caused by the collision and make the distribution of the deposition amount of the molten metal on the surface of the steel as uniform as possible to suppress the occurrence of splash and overcoating at both ends.

However, since the gas wiping device disclosed in Patent Document 1 closes only the jet port of the gas and narrows the gas jet width, the gas that circulates in the hollow of the nozzle is greatly contracted at the jet port, The spirals are periodically disturbed and the gas flow is disturbed so that overcoating or splashing occurs at the widthwise ends of the steel strip intermittently, so that overcoating and splashing can not be completely suppressed.

This will be described with reference to a schematic diagram shown in Fig. This figure is a simplified version of the gas wiping device W disclosed in Patent Document 1. Two closing members H and H are slidable in the forward direction (Y1 direction) The width of the central gas ejection opening E surrounded by the closing members H and H is variably adjusted. The gas (X3 direction) introduced from the rear of the gas wiping device W flows forward through the hollow and is discharged from the gas jetting port E (in the X4 direction) (X5), the swirling is generated by this abrupt axial flow, and this swirl disturbs the gas flow so that the gas is overcoated at the widthwise end of the steel strip Splashing occurs intermittently.

Patent Document 1: Japanese Patent Application Laid-Open No. 2007-284732

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and is directed to a gas wiping apparatus having a gas wiping nozzle for spraying a gas on the surface of a steel strip to adjust an amount of deposition of molten metal for plating adhered to the surface, And it is an object of the present invention to provide a gas wiping device which is excellent in an effect of suppressing overcoating and splashing at an end portion in the width direction.

In order to achieve the above object, a gas wiping apparatus according to the present invention is a gas wiping apparatus comprising: a gas wiping nozzle having a hollow gas wiping nozzle for spraying a gas onto a surface of a steel strip to adjust an adhering amount of molten metal for plating on the surface; Wherein the gas wiping nozzle includes a partition provided with a slit extending in the width direction of the steel strip for ejecting gas from the hollow and a gas inlet for introducing gas into the hollow, Left and right closing members capable of sliding along the slits and closing the right and left regions in accordance with the width of the steel strip are disposed and a gas spouting port is formed between the left and right closing members which are separated from each other, And left and right rectifying pieces (rectifying pieces) extending from the gas jetting-out port side end of each of the left and right closing members to the partition wall Value is, the gas flow path is formed between the rectification section of the left and right and will have a width and the width of the gas flow path of the gas jet port is the same.

The gas wiping nozzle constituting the gas wiping apparatus of the present invention is a three-shaped slit which is provided so as to extend in the width direction of the steel strip so as to oppose to the steel strip, and closes the left and right regions thereof, A slidable left and right closing member is disposed and a gas jet port is formed between the right and left closing members of the slit. The width of the gas jet port can be adjusted by sliding the left and right closing members. The sliding shapes of the right and left closing members are such that both of them slide in synchronism with each other by the same amount, or only one of the left and right closing members slides, and the width of the gas spouting port is changed by sliding the left and right closing members. It can be adjusted to the same extent as the width. More specifically, for example, a case where the width of the steel strip of about 700 to 1800 mm and the width of the gas ejection port are adjusted in the same manner, or the case where the width of the gas ejection opening is adjusted to a width widened by about 10 mm from the left and right sides have.

Left and right ends of the gas introduction port in the hollow of the gas-wiping nozzle are disposed to extend from the gas outlet port side end of each of the right and left closing members, and the gas flow path in the hollow is defined by the right and left rectifying pieces The gas flowing through the rectifying piece at the right and left ends of the gas flow path, among the gases introduced through the gas introduction port, is smoothly discharged from the gas discharge port via the end portion of the gas jetting port of the continuous rectifying piece and the closing member .

That is, the action of the gas flowing through the hollow of the gas-wiping nozzle is greatly (abruptly) axially flowed at the gas ejection port and the vortex is periodically vortexed by this axial flow to disturb the gas flow. Thereby, it is possible to completely overcoat or splash at the widthwise end of the steel strip due to the gas flow disturbed by the generated vortex.

In the present specification, the term "left and right" means that the width direction of the steel strip to be transported upward from the plating port is defined as the left and right direction, and the right and left sides of the steel strip, the left and right regions of the slit, .

The width of the gas flow path defined by the right and left rectifying pieces in the hollow of the gas wiping nozzle and the width of the gas spouting port are always kept the same. The width of the gas spouting port is changed by sliding the left and right closing members The width of the gas flow path and the width of the gas spouting port are changed to the same state. In this way, the right and left rectifying elements slide so that the rectifying elements in the present embodiment are structured to be disconnected from the partition walls.

Further, in a preferred embodiment of the gas wiping device according to the present invention, a falling piece which does not reach the lower surface of the hollow of the gas-wiping nozzle is fixed, and the lower surface of the lower portion of the gas- And the gas introduced into the gas flow path in the gas introduction port is adapted to be rectified in the course of flowing the falling piece and the rising piece.

Since the falling piece and the rising piece are provided at intervals in the gas flow passage, the gas is rectified in the course of the flow of the gas in the descending piece and the rising piece so that the pressure or the flow rate of the gas becomes as uniform as possible in the width direction of the gas flow passage .

As an embodiment relating to the sliding control of the left and right closing members, the left and right closing members are respectively slidable by a left sliding mechanism and a right sliding mechanism, which are inherent sliding mechanisms, and a left sliding mechanism and a right sliding mechanism The base is mounted on a common base, and the base is connected to the base sliding mechanism so as to be slidable, and a position sensor for detecting the position of the steel strip is provided in the vicinity of the gas spouting port. By the left sliding mechanism and the right sliding mechanism The base sliding mechanism slides the base on the basis of the position data of the steel strip detected by the position sensor, and the right sliding mechanism by the sliding of the base and the left sliding mechanism Can be given a shape that is adapted to slide while maintaining the width of the gas outlet with a closure member of the right and left it has already been adjusted by the sliding.

In the present embodiment, the sliding control of the right and left closing members is made by the left sliding mechanism and the right sliding mechanism, which are inherent sliding mechanisms. Here, the " sliding mechanism " includes a cylinder device that slides the closing member, an electric slider device that slides on the sliding substrate, and the like. When the cylinder device is used, the closing device may be constructed so that the closing member is attached to the end of the sliding piston so that the closing member can slide to the left and right according to the sliding of the piston. When the electric slider device is used, the electric slider and the closing member are connected to each other by a wire or the like so that the closing slider can be slid to the left and right as the electric slider slides left and right on the sliding substrate.

For example, data on the width of the pulley inputted to the process computer is transmitted to the left and right sliding mechanisms, and the left and right sliding mechanisms slide on the basis of the transmission data so that the width of the gas ejection opening is adjusted to a desired width.

The steel strip conveyed from the reduction annealing furnace is immersed in the molten metal in the plating port and transported vertically upward through the sink roll in the plating port, A part of molten metal adhered to both sides of the steel strip is wiped by the gas ejected from the apparatus so as to be adjusted to a desired adhesion amount. The width of the gas ejection opening is adjusted to a desired width based on the data of the width of the steel strip. However, there is a case where the center line of the gas ejection opening that has already been subjected to the width adjustment is shifted Sometimes.

Thus, in the present embodiment, the left sliding mechanism and the right sliding mechanism are mounted on a common base, and the base is connected to the base sliding mechanism so as to be slidable. Further, a position sensor for detecting the position of the steel strip near the gas spouting port is provided. Based on the position data of the steel strip from the position sensor (center line position data of the steel strip or position data of the right and left ends of the steel strip) So that the relative positions of the left and right sliding mechanisms for defining the width of the gas ejection opening are not changed so as to slide them so as to correspond to the position of the steel strip.

This base sliding mechanism can also be formed by a cylinder device, an electric slider device, or the like, as with the left and right sliding mechanisms. Further, with respect to "the position sensor for detecting the position of the steel strip is provided near the gas spouting port", the position sensor is provided in the vicinity of the gas spouting outlet as close to the gas spouting outlet as possible, But the term " near " herein includes a relatively wide range, for example, from the surface of the plating bath in the port to above the position of placement of the gas wiping apparatus.

As another embodiment of the sliding control of the right and left closing members, the left and right closing members are slidable by a left sliding mechanism and a right sliding mechanism, which are inherent sliding mechanisms, respectively. And the left and right closing members are slid by the left sliding mechanism and the right sliding mechanism to adjust the width of the gas ejection port. Based on the position data of the steel plate detected by the position sensor, The sliding mechanism and the right sliding mechanism are configured to slide the left and right closing members while maintaining the width of the gas ejection opening already adjusted.

In the present embodiment, the widths of the gas ejection openings are adjusted by the left sliding mechanism and the right sliding mechanism. However, these left and right sliding mechanisms are not mounted on a common base, The left and right sliding mechanisms slide synchronously in the same direction in the same direction based on the information data so that the left and right closing members are slidably controlled so as to correspond to the positions of the strips while maintaining the width of the gas ejection openings already adjusted.

Further, it is preferable that the clearance from the left and right ends of the steel strip to the gas outlet side end portions of the left and right closing members is the same length (s), and is preferably in the range of 0? S? 10 mm.

(S) from the right and left ends of the steel strip to the gas ejection port side end of each of the right and left closing members is in the range of 0? S? 10 mm, there is no occurrence of splash or very little It was proved that no nozzle clogging occurred.

As can be understood from the above description, according to the gas wiping apparatus of the present invention, the gas outlet port side end portions of the left and right closing members in the slit forming the gas outlet port and the gas flow path defining the gas flow path in the hollow of the gas wiping nozzle By the very simple structure improvement that connects the left and right rectifying pieces, the gas that circulates in the hollow of the gas-wiping nozzle is greatly shrunk from the gas ejection port, and a vortex occurs periodically by this axial flow, The effect of disturbing the gas flow does not occur, and overcoating and splashing at the widthwise ends of the steel strip caused by the disturbed gas flow can be completely eliminated.

1 is a schematic diagram showing a configuration of a molten metal plating apparatus.
2 is a perspective view of one embodiment of a gas wiping device.
3 is a sectional view taken along the line III-III in Fig.
4 is a sectional view taken along the line IV-IV in Fig.
Fig. 5 is a view corresponding to Fig. 3 as a cross-sectional view of another embodiment of the gas wiping apparatus. Fig.
6 is a sectional view taken along the line VI-VI in Fig.
7 is a schematic view of an embodiment of a sliding mechanism of right and left closing members.
8 is a schematic view of another embodiment of the sliding mechanism of the right and left closing members.
9A is a longitudinal sectional view of the analysis model, and FIG. 9B is a sectional view taken along the line bb in FIG. 9A.
FIG. 10A is a diagram showing the analysis result of the comparative example, and FIG. 10B is a diagram showing the analysis result of the embodiment.
Fig. 11 is a schematic diagram for explaining the abrupt flow of gas in an obstructing member slidable in a conventional gas wiping apparatus. Fig.

Hereinafter, an embodiment of the gas wiping apparatus of the present invention will be described with reference to the drawings.

(Plating apparatus)

Fig. 1 is a schematic view of a molten metal plating apparatus. The plating apparatus shown in the figure is a plating apparatus in which a plating bath made of a molten metal (M) such as molten zinc or molten aluminum is accommodated, and a plating port (Y) The steel strip R is rotatably arranged so that the steel strip K sent from the reduction annealing furnace through the slats or the like not shown is immersed in the molten metal M and transported vertically upward through the sink roll R (In the X1 direction).

The molten metal is adhered to both sides of the steel strip K conveyed vertically upward. The molten metal is adhered to both sides of the conveying path of the steel strip K conveyed vertically upward above the plating port Y, A portion of the molten metal adhered to both sides of the steel strip K by the gas (air, nitrogen, inert gas, etc.) ejected from these gas wiping devices 10, So that it is adjusted to a desired deposition amount.

(Embodiment 1 of the gas wiping apparatus)

Fig. 2 is a perspective view showing an embodiment of a gas wiping apparatus constituting the plating apparatus of Fig. 1, Fig. 3 is a sectional view taken along a line III-III in Fig. 2, Fig. 4 is a cross- Fig.

The gas wiping device 10 shown in Figs. 2 to 4 is provided with a hollow gas wiping nozzle 1 and a gas inlet pipe 2 provided behind the gas wiping nozzle 1, in which gas is provided in the hollow of the gas wiping nozzle 1 (Gas supply source) for supplying gas to the gas supply source 1b.

The gas wiping nozzle 1 is provided so as to extend in the width direction of the steel strip K and has a slit 1a '(whose total width is T) for ejecting gas from the hollow thereof, and the slit 1a' Left and right closure members 2, 2 which are capable of sliding along the slit 1a '(in the Y1 direction) are disposed in the left and right closure members 2, And a gas jet opening 1a is formed in the slit region between the first and second electrodes 2 and 2.

A gas inlet pipe 1b is communicated with the inner side of the gas wiping nozzle 1 and a partition wall 1d having a plurality of gas inlet ports 1e is provided in front of the gas inlet pipe 1b. Gas supplied from an unshown gas supply device is introduced into the gas-wiping nozzle 1 through the gas inlet pipe 1b (in the X2 direction) and introduced into the hollow through the gas inlet 1e.

Further, in the hollow of the gas-wiping nozzle 1, left and right rectifying elements (not shown) provided so as to extend from the gas outlet side end portions 2a and 2a of the left and right closing members 2 and 2 to the partition wall 1d, And the space delimited by the upper and lower surfaces of the right and left rectifying pieces 1c and 1c serves as a gas flow path GR.

The gas wiping device 10 is designed such that the width t of the gas flow path GR formed between the right and left rectifying pieces 1c and 1c and the width t of the gas spouting port 1a are always the same Consists of. That is, one end of each of the right and left flow-regulating members 1c and 1c is fixed in an orthogonal posture with respect to the gas outlet side end portions 2a and 2a of the left and right closing members 2 and 2, The width t of the gas ejection port 1a and the width t of the gas passage GR are both the same as each other because the other ends of the right and left rectifying pieces 1c and 1c are completely disconnected from the partition wall 1d. The width can be adjusted variably.

The width t of the gas ejection port 1a can be adjusted by the sliding (Y1 direction) of the right and left closing members 2 and 2 and the thickness of the strips K And the width t of the gas jet port 1a are adjusted to a width widened by about 10 mm from the left and right of the width of the strip K, And the width t of the gas jetting port 1a is adjusted as desired according to the width change of the steel strip K. [

The sliding form of the left and right closing members 2 and 2 may be a form in which both the left and right closing members slide in synchronism with each other by the same amount or a form in which only one of the left and right closing members slides.

3, the rectifying pieces 1c and 1c at the right and left ends of the gas flow path GR among the gas (X3 direction) introduced into the gas flow path GR from the plurality of gas introducing ports 1e, Is smoothly discharged from the gas spouting port 1a (X4 direction) through the continuous flow of the rectifying piece 1c and the end portion 2a of the closing member 2 at the gas spouting port side.

That is, the gas circulating in the hollow of the gas-wiping nozzle 1 is rapidly flown in the gas outlet 1a and the vortex is periodically generated by the axial flow so that the vortex can not disturb the gas flow . Thereby, it is possible to completely overcoat or splash at the widthwise end of the steel strip due to the gas flow disturbed by the generated vortex.

(Embodiment 2 of the gas wiping apparatus)

Fig. 5 is a cross-sectional view of another embodiment of the gas wiping device in a form corresponding to Fig. 3, and Fig. 6 is a sectional view taken along the line VI-VI in Fig.

In the illustrated gas wiping device 10A, a falling piece 3a which does not reach the lower surface of the hollow upper surface is fixed in the gas passage GR, and a hollow bottom surface at a position apart from the falling piece 3a And the gas introduced into the gas channel GR from the gas inlet 1e flows through the descending piece 3a and the rising piece 3b X3 '.

The other ends of the right and left rectifying pieces 1c and 1c are located forward of the rising piece 3b and the falling piece 3a and slide in front of them in accordance with the variation of the width of the gas spouting hole 1a.

By this rectification, the flow velocity and pressure of the gas introduced through the plurality of gas introduction ports 1e are made as uniform as possible in the width direction of the gas flow path GR so that the gas having the same flow rate or pressure is spread across the width direction of the steel strip K .

The gas wiping device 10A of the present embodiment is also applicable to the rectifying devices 1c and 1d at the right and left ends of the gas introduced from the plurality of gas introducing ports 1e into the gas flow path GR, 1c are smoothly discharged from the gas outlet 1a via the continuous gas flow outlet side end 2a of the rectifying piece 1c and the closing member 2 to generate a vortex so that the gas flow is disturbed Tongue action can not occur.

(Embodiment 1 of a sliding mechanism of right and left closing members)

Next, referring to Fig. 7, the first embodiment of the sliding mechanism of the right and left closing members is described with the gas wiping device 10 being described.

In the illustrated sliding mechanism, the left and right closing members 2, 2 are slidable left and right by their own left sliding mechanism 5A and right sliding mechanism 5B, respectively, 5A and the right sliding mechanism 5B are mounted on a common base 6. The common base 6 is connected to the base sliding mechanism 7 and is slidable.

The electric slider constituting the left closing member 2 and the left sliding mechanism 5A are connected in a substantially annular shape through the pulley 9 by the two wires W1 and W1, The left closing member 2 is also slidable in the left and right direction (Z1 'direction) when the left closing member 5A is slid to the left and right (in the Z1 direction). Similarly, the electric slider constituting the right closing member 2 and the right sliding mechanism 5B is also connected in a substantially annular shape through the pulley 9 by the two wires W2 and W2, The right closing member 2 is also slidable in the left and right direction (Z2 'direction) when the sliding member 5B slides left and right (Z2 direction).

The common base 6 on which the left sliding mechanism 5A and the right sliding mechanism 5B are mounted is slidable by an electric cylinder constituting the base sliding mechanism 7, The position of the left and right sliding mechanisms 5A and 5B enabling the sliding of the left and right closing members 2 and 2 positioned to define the jetting port 1a is fixed and the base sliding mechanism 7 Control is performed to align the center line CL2 of the strip K and the center line CL1 of the gas ejection port 1a while the base 6 slides in the middle of the conveyance.

More specifically, data on the width of the strip K conveyed from the process computer PC is transmitted to the left and right sliding mechanisms 5A and 5B, and the left and right sliding mechanisms 5A, And 5B slide to slide the left and right closing members 2 and 2 to form a gas jet opening 1a having a desired width t.

On the other hand, two pairs of position sensors 4, 4 disposed near the gas spouting port 1a are sensing the vicinity of the right and left ends of the strip K passing the transporting path and the sensing data is transmitted to the base sliding mechanism 7 As shown in Fig. The center line CL2 of the strip K in the vicinity of the gas ejection port 1a is calculated by the sensing data from the left and right position sensors 4 and 4 and the center line CL2 of the center line CL2 of the gas ejection port 1a CL1), the base sliding mechanism 7 and the base 6 slide by the amount of the difference (in the Z3 direction), and the left and right sliding mechanisms The right and left closing members 2 and 2 are slid so that the center lines CL1 and CL2 of both the gas ejection openings 1a and K coincide with each other as the sliders 5A and 5B synchronously slide, do.

(Embodiment 2 of the right and left closing member sliding mechanism)

Next, referring to Fig. 8, a second embodiment of the sliding mechanism of the right and left closing members is described with the gas wiping device 10 being described.

The difference between the sliding mechanism shown in Fig. 7 and the sliding mechanism shown in Fig. 7 is that the left and right sliding mechanisms 5A and 5B are not mounted on the common base in the illustrated sliding mechanism, And 5B are points that follow the meandering of the strip K by sliding the same amount of both in synchronism with the meandering of the strip K after forming the gas spout 1a of the desired width t. And the position sensor 4A is capable of being slid by the position sensor slide mechanism 8. In this case,

The position sensor 4A is slid in the position sensor slide mechanism 8 so as to follow the meandering of the strip K and the right edge ed of the strip K is sensed and the sensed data is transmitted to the left and right sliding mechanisms 5A, The left and right closing members 2 and 2 are slid by the same amount in the same direction so that the right and left closure members 2 and 2 are slid by the same amount with respect to the gas jet opening 1a, (ed) is positioned to a desired position.

[Turbulence analysis and its results verifying the degree of splashing]

9 (a) and 9 (b), the present inventors created a simulation model in a computer and performed LES turbulence analysis (LES: an unsteady turbulent flow analysis method that directly calculates a vortex larger than an analysis cell without modeling) . As shown in Fig. 9B, the width t1 of the steel strip is 150 mm, the width t2 of the gas discharge port and the gas spray width t3 are 150 mm, the height t4 of the gas discharge port is 1.2 mm, The gap t5 between the gas ejection openings of the two gas wiping devices opposed to each other with the pulley interposed therebetween was set to 20 mm. The air pressure in the gas discharge port was set at 40 kPa.

At the time of modeling, as shown in FIG. 9 (b), a range from the center to the center of the steel strip was modeled (the total number of models was 2654640). Fig. 10 (a) is an analysis result chart obtained by modeling the conventional example of Fig. 11, and Fig. 10 (b) is an analysis result obtained by modeling an embodiment corresponding to the present invention. Respectively.

In the right end region of Fig. 10 (a), the flow direction of the air flows obliquely upward to the right and downward to the right oblique direction (this demonstrates a large splash) It is proved that the flow direction of the slant is significantly lower than the right slant upward or the right slant downward so that the occurrence of splash is extremely small.

[Experiments on the range of conveying speed (conveying speed) of the steel strip during the plating process and the results thereof]

The inventors of the present invention have found that when the gas wiping apparatus (embodiment) shown in Figs. 3 and 4 and the conventional gas wiping apparatus (comparative example) shown in Fig. 11 are applied respectively, . Specifically, the thickness of the steel strip was 0.4 mm, the width was 1200 mm, and the clearance from the left and right ends of the steel strip to the end of the gas outlet was 0 mm, and the adhesion amount of zinc as a molten metal for plating was 120 g / m ² To verify the speed range of the line. In the case of the gas wiping device according to the second embodiment, the gas wiping device according to the second embodiment shown in Figs. 5 and 6 is not carried out. However, for the gas wiping device according to the first embodiment, It is clear that the effect of rectifying the gas by the gas wiping device shown in Figs. 3 and 4 can be expected to be higher than that of the gas wiping device shown in Figs.

The experimental results are shown in Table 1 below. In Table 1, & cir & indicates that splashes are less likely to be reattached to the steel strip, DELTA is attached to the nozzles due to splashing but not reattached to the steel strip, And reattached to the steel strip.

As shown in Table 1, in the gas wiping device of the embodiment, it was confirmed that splashes did not re-adhere to the steel strip when they were shipped in a range of up to 240 mpm.

On the other hand, in the gas wiping apparatus of the comparative example, the range of the conveying speed at which the same effect can be expected was up to 180 mpm.

From the results of this experiment, it was proven that the operation speed of the passing plate can be increased by 3% or more as compared with the case where the conventional gas wiping apparatus is applied.

[Experiments proving the optimum range of clearance from the left and right ends of the steel strip to the end of the gas outlet port and results thereof]

The present inventors also experimented with the magnitude of the occurrence of splashes and the reattachment to the steel strip by variously changing the clearance from the right and left ends of the steel strip to the end of the gas spouting port. Table 1 described above shows various conditions and experimental results.

From the results of this experiment, it was found that the Examples were good in the region where the gas pressure was high and the sheet speed was high as compared with the Comparative Example. From the experimental results of the examples, it has been demonstrated that the clearance from the left and right ends of the steel strip to the end of the gas ejection opening is preferably in the range of 0 mm to 10 mm.

Although the embodiment of the present invention has been described above with reference to the drawings, the specific structure is not limited to this embodiment, and the design changes are included in the present invention even if the design changes are made without departing from the gist of the present invention.

One… Gas wiping nozzle, 1a ... Gas outlet, 1a '... Slit, 1b ... Gas inlet pipe, 1c ... Rectifier, 1d ... Bulkhead, 1e ... Gas inlet, 2 ... Closure member, 2a ... The gas outlet side end of the closing member, 3a ... Descending piece, 3b ... Rise, 4, 4A ... Position sensor, 5A ... Left sliding mechanism, 5B ... Right sliding mechanism, 6 ... Base (common base), 7 ... Base sliding mechanism, 8 ... Position sensor slide mechanism, 10,10A ... Gas wiping device, M ... Molten metal (plating bath), K ... Coil, Y ... Plating port, R ... Sink roll, W1, W2 ... Wire, PC ... Process computer, CL1 ... The center line of the gas outlet, CL2 ... The center line of the pulley, ed ... Velvet edge of the pulley

Claims (7)

1. A gas wiping apparatus having a hollow gas wiping nozzle for spraying a gas on a surface of a steel strip to adjust an amount of deposition of molten metal for plating on the surface,
Wherein the gas wiping nozzle includes a partition provided with a slit extending in the width direction of the steel strip for ejecting gas from the hollow and a gas inlet for introducing gas into the hollow,
Wherein the slit is provided with right and left closing members capable of closing left and right regions along the width of the steel strip and slidable along the slit and a gas spouting port formed between the left and right closing members spaced apart from each other,
In the hollow, right and left rectifying elements extending from the gas jetting port side end of each of the left and right closing members to the partition wall are disposed, a gas flow path is formed between the right and left rectifying elements,
Wherein the width of the gas ejection port and the width of the gas passage are the same. The method according to claim 1,
Wherein the left and right closing members and the right and left rectifying members slide in synchronization to adjust a width of the gas ejection port and a width of the gas flow path. The method according to claim 1 or 2,
A rising piece that does not reach the bottom surface is fixed to the upper surface of the hollow of the gas-wiping nozzle, and a rising piece that does not reach the upper surface is fixed to the lower surface of the position apart from the falling piece,
Wherein the gas introduced into the gas flow path from the gas introduction port is rectified in the process of flowing the falling piece and the rising piece. The method according to claim 1 or 2,
Each of the right and left closing members is slidable by a left sliding mechanism and a right sliding mechanism, which are inherent sliding mechanisms,
The left sliding mechanism and the right sliding mechanism are mounted on a common base, the base is connected to the base sliding mechanism so as to be slidable,
A position sensor for detecting the position of the steel strip is provided in the vicinity of the gas jet port,
The left and right closing mechanisms slide by the left sliding mechanism and the right sliding mechanism to adjust the width of the gas ejection port,
The base sliding mechanism slides the base on the basis of the position data of the steel strip detected by the position sensor and the right sliding mechanism and the left sliding mechanism slide by sliding the base so that the right and left closing members are already adjusted, And is adapted to slide while maintaining its width. The method according to claim 1 or 2,
Each of the right and left closing members is slidable by a left sliding mechanism and a right sliding mechanism, which are inherent sliding mechanisms,
A position sensor for detecting the position of the steel strip is provided in the vicinity of the gas spouting port,
The left and right closing mechanisms slide by the left sliding mechanism and the right sliding mechanism to adjust the width of the gas ejection port,
Wherein the left sliding mechanism and the right sliding mechanism slide on the right and left closing members while maintaining the width of the gas ejection opening already adjusted based on the position data of the pulley detected by the position sensor. The method of claim 4,
Wherein the clearance from the left and right ends of the pulley to the gas ejection port side end of each of the left and right closing members is adjusted to have the same length (s) and is in the range of 0? S? 10 mm. The method of claim 5,
Wherein the clearance from the left and right ends of the pulley to the gas ejection port side end of each of the left and right closing members is adjusted to have the same length (s) and is in the range of 0? S? 10 mm.

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