JP6958250B2 - Continuous molten metal plating equipment and continuous molten metal plating processing method - Google Patents

Description

The present invention relates to a continuous molten metal plating apparatus and a continuous molten metal plating treatment method.

As a facility for continuously plating a metal strip on a steel strip, a continuous molten metal plating apparatus 10 as shown in FIG. 9 is generally used. In the continuous molten metal plating apparatus 10, the steel strip S is continuously immersed in the molten metal plating bath 3 in the pot 11, and then the direction is changed by the bath roll 13 installed in the molten metal plating bath 3 to melt the steel strip S. Continuously pull up from the metal plating bath 3. Further, the continuous molten metal plating apparatus 10 includes a gas wiping apparatus including a slit nozzle 15 that injects gas into the steel strip S pulled up from the molten metal plating bath 3. In the gas wiping device, a gas jet is sprayed on both sides of the steel strip S by the slit nozzle 15 to blow off the excess molten metal 5 adhering to the surface of the steel strip S, and the molten metal adheres to the surface of the steel strip S. Adjust the amount to a predetermined value.

Here, when the plate passing speed of the continuous molten metal plating apparatus 10 becomes high, the amount of molten metal adhering to the steel strip S pulled up from the molten metal plating bath 3 of the pot 11 increases. Therefore, the amount of molten metal scraped off by the gas wiping device increases, and the pressure of the gas jet injected by the slit nozzle 15 needs to be higher than before. In particular, in the case of thinning to reduce the amount of molten metal adhering to the surface of the steel strip S, it is necessary to further increase the pressure of the gas jet for operation.

Here, when a gas jet is blown onto the steel strip from the gas wiping device, zinc scraped off from the surface of the steel strip by the gas jet is scattered. The molten metal that scatters in this way is called a splash. Since splashes are likely to occur when the pressure of the gas jet increases, a technique has been conventionally proposed to prevent the generated splashes from reattaching to the steel strip and causing flaws in the steel strip. For example, in Patent Document 1, a pair of blocking plates are provided between the plating bath surface and the gas wiping nozzle so as to sandwich a steel strip pulled up from the molten metal plating bath, thereby suppressing the oxygen concentration in the top dross generation region. At the same time, the amount of splash adhered to the steel strip is reduced.

Japanese Unexamined Patent Publication No. 2013-185227

However, it was found that when the plate passing speed of the continuous molten metal plating apparatus was further increased to 150 mpm or more, a large amount of metal powder was scattered to the outside of the pot. FIG. 10 shows an example in which the amount of metal powder scattered to the outside of the pot was measured by changing the plate passing speed. As shown in FIG. 10, when the plate passing speed is 100 mpm, the metal powder hardly scatters to the outside of the pot. However, the plate passing speed increases, and when it exceeds 130 mpm, the amount of scattered metal powder begins to increase, and when it reaches 150 mpm, it becomes about ten times as much as in the case of 100 mmp, and when it reaches 200 mmp, it becomes about several tens of times as much as in the case of 100 mmp. As a result of investigating the cause, the metal powder scattered to the outside of the pot is generated at the lower part of the slit nozzle 15 of the gas wiping device, and as shown in FIG. 11, the movement of the steel strip S pulled up from the molten metal plating bath 3 It was found that it moves on the flow F near the bath surface that accompanies it. This flow F passes near the bath surface from the steel strip S toward the edge portion 11a of the pot 11, and blows up from the edge portion 11a of the pot 11. For this reason, a large amount of minute metal powder flies around the pot, which reduces the workability of the operator who works around the continuous molten metal plating apparatus and makes continuous operation difficult.

With the technique described in Patent Document 1, it is not possible to block the gas flow from the steel strip that appears strongly when the plate passing speed of the continuous molten metal plating apparatus becomes 150 mpm or more to the edge of the pot, and the outside of the pot The amount of metal powder scattered on the surface cannot be reduced.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to reduce the amount of metal powder scattered to the outside of the pot when the plate passing speed is high. It is an object of the present invention to provide a new and improved continuous molten metal plating apparatus and a continuous molten metal plating treatment method which are possible.

In order to solve the above problems, according to a certain viewpoint of the present invention, gas is blown by a gas wiping device onto a steel strip pulled upward from a molten metal plating bath housed in a pot at a plate passing speed of 150 mpm or more. , In a continuous molten metal plating device that adheres molten metal of a predetermined thickness to the surface of a steel strip, a plating bath that blows up from the steel strip toward the edge of the pot as the steel strip is pulled up from the molten metal plating bath. A blocking member for blocking the upper flow is provided, and the blocking member is arranged between the steel strip and the edge region including the edge of the pot, and the edge of the pot in the direction from the surface of the steel strip to the front surface of the pot. part Ru disposed between the edge region to the position of the external side 100mm from the edge of the pot from the position of the steel band side 100mm from, a continuous molten metal plating apparatus is provided.

At this time, the blocking member is attached to the pot in the edge region of the pot, and the height of the blocking member from the mounting surface to the pot is preferably 200 mm or more and 400 mm or less.

Further, in order to solve the above problems, according to another viewpoint of the present invention, a gas wiping device is used for a steel strip pulled upward from a molten metal plating bath housed in a pot at a plate passing speed of 150 mpm or more. In a continuous molten metal plating apparatus that sprays gas to adhere molten metal of a predetermined thickness to the surface of a steel strip, it is blown from the steel strip toward the edge of the pot as the steel strip is pulled up from the molten metal plating bath. A blocking member for blocking the flow on the rising plating bath is provided, and the blocking member is composed of a mesh-shaped plate-shaped member in which a plurality of through holes are formed. Provided is a continuous molten metal plating apparatus formed so as to be 400 μm or less and arranged between a steel strip and an edge region including an edge of a pot.

Further, the blocking member may be installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip in the direction from the surface of the steel strip toward the front surface of the pot.

At this time, the blocking member may be installed so that the length in the vertical direction is 100 mm or more and 200 mm or less, and the lower end of the blocking member is at a height of 0 mm or more and 20 mm or less from the bath surface of the molten metal plating bath. good.

The blocking member may be provided so as to be perpendicular to the bath surface of the plating bath or to be inclined toward a predetermined inclination angle steel strip side from the vertical state.

Further, the blocking member may be arranged so that the blocking surface of the blocking member is substantially orthogonal to the flow.

An additional member that bends toward the steel strip may be provided at the tip of the blocking member.

The width of the blocking member is made larger than the width of the steel strip.

Further, in order to solve the above problems, according to another viewpoint of the present invention, in a continuous molten metal plating apparatus for adhering a molten metal having a predetermined thickness to the surface of a steel strip, molten metal plating housed in a pot. Gas is blown by a gas wiping device onto the steel strip pulled upward from the bath at a plate passing speed of 150 mpm or more, and blown from the steel strip toward the edge of the pot as the steel strip pulled up from the molten metal plating bath moves. The flow on the rising plating bath is arranged between the steel strip and the edge region including the edge of the pot, and is 100 mm from the edge of the pot on the steel strip side in the direction from the surface of the steel strip to the front surface of the pot. Provided is a continuous molten metal plating treatment method in which a blocking member is installed between the position and the edge region from the edge of the pot to the position 100 mm on the outer side.

As described above, according to the present invention, it is possible to reduce the amount of metal powder scattered to the outside of the pot even when the plate passing speed is high.

It is explanatory drawing which shows an example of the blocking member installed in the pot edge part of the continuous molten metal plating apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows another example of the blocking member installed in the pot edge part of the continuous molten metal plating apparatus which concerns on this embodiment. It is explanatory drawing which shows another example of the blocking member installed in the pot edge part of the continuous molten metal plating apparatus which concerns on this embodiment. It is explanatory drawing which shows another example of the blocking member installed in the pot edge part of the continuous molten metal plating apparatus which concerns on this embodiment. It is explanatory drawing which shows an example of the blocking member installed in the vicinity of the steel strip of the continuous molten metal plating apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows the other example of the blocking member installed in the vicinity of the steel strip of the continuous molten metal plating apparatus which concerns on this embodiment. As a comparative example, it is explanatory drawing which shows the continuous molten metal plating apparatus provided with the blocking member in the vicinity of a steel strip. It is explanatory drawing which shows the simulation result of the airflow on the bath of a pot and near the edge. It is explanatory drawing which shows one structural example of the continuous molten metal plating apparatus. It is a graph which shows one relation example of a plate passing speed and the amount of metal powder scattered to the outside of a pot. It is explanatory drawing which shows the flow near the bath surface where the metal powder generated in the lower part of a gas wiping device moves to the outside of a pot.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

<1. Overview>
In the continuous molten metal plating apparatus according to the embodiment of the present invention, gas is blown by a gas wiping apparatus onto a steel strip pulled upward from the molten metal plating bath, and molten metal having a predetermined thickness is applied to the surface of the steel strip. It is a device to attach. As shown in FIG. 9, the continuous molten metal plating apparatus continuously immerses the steel strip S in the molten metal plating bath 3 in the pot 11 and pulls it upward, and then uses the slit nozzle 15 to pull up the surface of the steel strip S. Inject gas against. As a result, the excess molten metal 5 adhering to the surface of the steel strip S is blown off, and the amount of molten metal adhering to the surface of the steel strip S is adjusted to a predetermined value.

In the continuous molten metal plating apparatus according to the present embodiment, when the plate passing speed of the steel strip S becomes as high as 150 mpm or more, the metal powder generated at the lower part of the slit nozzle 15 is generated from the steel strip S side to the pot 11. A blocking member is provided to prevent the gas from scattering to the outside of the pot 11 on the flow of gas toward the edge portion 11a of the steel. The blocking member is arranged between the steel strip S and the edge region including the edge portion 11a of the pot 11, and blocks the flow of gas from the steel strip S side toward the edge portion 11a of the pot 11. As a result, the flow of this gas is reduced, and the amount of metal powder scattered to the outside of the pot 11 is reduced. Hereinafter, the specific configuration and arrangement of the blocking member will be described in detail.

<2. Blocking member>
[2-1. First form (installation on the edge of the pot)]
An embodiment of a blocking member included in the continuous molten metal plating apparatus according to the embodiment of the present invention will be described with reference to FIGS. 1 to 4. 1 to 4 are explanatory views showing an example of a form of a blocking member installed at a pot edge of the continuous molten metal plating apparatus according to the present embodiment. The blocking member may be installed at least in front of the pot 11. In the present invention, the front surface of the pot 11 is provided with the steel strip S pulled up from the molten metal plating bath 3 and the surface facing the pot 11 (that is, the snout) in the continuous molten metal plating apparatus 10 shown in FIG. The side that is not plated).

The blocking member is arranged at a position where it can block the flow of gas from the steel strip S side toward the edge portion 11a of the pot 11 and prevent the metal powder from scattering to the outside of the pot 11. In the first embodiment shown below, the blocking member is arranged in the edge region including the edge portion 11a of the pot 11. The plating bath surface is lower than the upper end of the pot 11. Therefore, the gas flowing on the plating bath from the steel strip side blows upward at the edge portion 11a of the pot 11. Therefore, by arranging the blocking member in the edge region including the edge portion 11a of the pot 11 as in the first embodiment, the flow that blows upward at the edge portion 11a of the pot 11 is effectively blocked.

(1) Basic Configuration First, based on FIG. 1, a basic configuration of a blocking member installed at a pot edge of a continuous molten metal plating apparatus will be described. As shown in FIG. 1, the continuous molten metal plating apparatus includes a blocking member 20a in a pot 11 in which a molten metal plating bath 3 is housed. The blocking member 20a is a plate-shaped member extending in the depth direction of the paper surface of FIG. 1, and is formed of a heat-resistant member having a melting point higher than the temperature of the molten metal plating bath 3. For example, the blocking member 20a is formed of a steel plate. The blocking member 20a may be a plate-shaped member having no through hole so that the flow of gas flowing on the plating bath can be completely blocked. Alternatively, since the scattering of metal powder to the outside of the pot 11 can be suppressed if at least the gas flow can be reduced, the blocking member 20a is formed from, for example, a mesh-like plate-shaped member having fine through holes formed therein. Is more preferable.

When the width direction of the pot 11 is the same as the plate width direction of the steel strip S, when the blocking member 20a is formed of a plate-shaped member having no through hole, a part of the gas colliding with the blocking member 20a is in the pot 11. It flows in the width direction, and metal powder scatters outside the pot 11. Therefore, although the metal powder is surely collected, a part or the entire surface of the blocking member 20a is configured by using a porous mesh plate-like member in order to let a part of the gas flow as it is to the front surface of the pot 11. .. As a result, a part of the gas flows to the front through the through hole formed in the blocking member 20a, and the gas flow in the width direction is reduced, so that the metal powder can be prevented from scattering from the width direction of the pot 11. .. The portion of the blocking member 20a that forms the through hole may be determined by investigating, for example, a portion that can prevent the metal powder from scattering in the width direction by an experiment or the like.

The diameter of the through hole (hereinafter, also referred to as “mesh diameter”) is 300 μm or more and 400 μm or less. The diameter of the through hole is the diameter equivalent to the circle converted to the diameter of the circle having the opening area of the through hole, and the shape of the through hole is not limited. If the diameter of the through hole is less than 300 μm, the through hole is too small, so that gas flows in the width direction of the pot 11 and metal powder scatters in the width direction of the pot 11. On the other hand, the size of the metal powder is about 200 μm, and if the diameter of the through hole exceeds 400 μm, the opening of the through hole becomes too large for the size of the metal powder, so that the metal powder passes through the through hole. .. Therefore, when the blocking member 20a is provided with a through hole, the diameter of the through hole is set to 300 μm or more and 400 μm or less. The diameter of the through hole is an average value of the diameters of the through hole formed in the plate-shaped member. For example, the diameter of the through holes may be a value obtained by randomly extracting 20 through holes formed in the plate-shaped member and averaging their diameters.

The shape of the through hole formed in the mesh-shaped plate-shaped member is not limited to a circular shape, and may be, for example, an elliptical shape, a rectangular shape, a polygonal shape, or the like.

Since the gas flow from the steel strip S side toward the edge portion 11a of the pot 11 occurs over the entire width of the steel strip S, the blocking member 20a has a length equal to or longer than the width of the steel strip S in the depth direction of the paper surface of FIG. It is arranged so as to face the band S. In this embodiment, the edge region including the edge portion 11a of the blocking member installed the pot 11, relative to the edges 11a is a front surface of the pot 11, the position of the external side 100mm from the position _{P 1} of the steel strip side 100mm It means a region of up to P _2, corresponding to a range d of FIG. At least a portion of the blocking member 20a is, when positioned on the steel band side from the position P ₁ of the steel strip side 100mm from the edge 11a of the pot 11, for example, it hinders the work of the dross removal operations and the like in the plating bath 3 by the operator, This will reduce the workability of the operator. Further, at least a portion of the blocking member 20a is, when positioned on the outer side from the position P ₂ of the outer side 100mm from the edge 11a of the pot 11, outside the metal powder of the pot 11 to unacceptably becomes possible to scatter pot 11 The purpose of installing the blocking member 20a, which is to prevent the metal powder from scattering to the outside, cannot be achieved.

The blocking member 20a is provided so as to be inclined by a predetermined inclination angle θ from the vertical or vertical state to the bath surface of the plating bath 3 toward the steel strip S side. The inclination angle θ is preferably 90 ° or less. When the inclination angle θ is made larger than 90 °, the blocking member 20a is in a state of being inclined from the bath surface of the plating bath 3 toward the upper end of the edge portion 11a of the pot 11. A flow of gas on the plating bath towards the edge 11a is formed. Therefore, the amount of metal powder generated on the steel strip S side flows out to the outside of the pot increases. On the other hand, when the blocking member 20a is tilted from the state perpendicular to the bath surface of the plating bath 3 to the outside of the pot, the flow of gas blown up at the edge 11a of the pot 11 is promoted to the outside of the pot, and the steel strip S The amount of metal powder generated on the side flowing out of the pot increases. From this, it is preferable that the blocking member 20a is provided so as to be inclined by a predetermined inclination angle θ from the vertical or vertical state to the bath surface of the plating bath 3 toward the steel strip S side.

In this way, the inclination angle θ of the blocking member 20a is determined so that the gas flow from the steel strip S side toward the edge portion 11a of the pot 11 can be blocked or suppressed by the blocking member 20a. It is preferable to install the blocking member 20a so that the blocking surface is substantially orthogonal to the gas flow. Thereby, the gas flow from the steel strip S side to the edge portion 11a of the pot 11 can be blocked or suppressed by the blocking member 20a.

The height h of the blocking member 20a is preferably 200 mm or more and 400 mm or less. The height h of the blocking member 20a refers to the length in the direction perpendicular to the mounting surface 11b of the pot 11 to which the blocking member 20a is mounted. For example, as shown in FIG. 1, when the mounting surface 11b of the blocking member 20a with the pot 11 is inclined to the outside of the pot 11 with respect to the front surface (edge portion 11a), the bath surface of the plating bath 3 is formed. The height h of the blocking member 20a is the length in the direction perpendicular to the mounting surface 11b, which is inclined from the vertical direction.

When the height h of the blocking member 20a is smaller than 200 mm, the effect of blocking the gas flow is small, and the amount of metal powder generated on the steel strip S side flowing out to the outside of the pot increases. Further, when the height h of the blocking member 20a is larger than 400 mm, the size of the blocking member 20a becomes large, which reduces the workability of the operator. In particular, when the blocking member 20a is installed so as to be inclined toward the steel strip S side, the blocking member 20a covers the bath of the plating bath 3 and further reduces the workability of the operator. Therefore, the height h of the blocking member 20a is preferably 200 mm or more and 400 mm or less.

As described above, by installing the blocking member 20a at the pot edge of the continuous molten metal plating apparatus, it is possible to effectively block the upward flow at the edge 11a of the pot 11, and the steel strip S It is possible to prevent the metal powder generated on the side from scattering to the outside of the pot. As a result, the workability of the operator working around the pot 11 of the continuous molten metal plating apparatus is not deteriorated, and the molten metal plating process can be continuously operated.

(2) Deformation Example Hereinafter, FIGS. 2 to 4 show a modification of the blocking member of the first form.

The blocking member 20b installed at the pot edge of the continuous molten metal plating apparatus shown in FIG. 2 is provided at the first member 21 corresponding to the blocking member 20a having the basic configuration shown in FIG. 1 and at the tip of the first member 21. It is composed of a second member 23 which is an additional member which is bent toward the steel strip S side. By providing such an additional member, it is possible to prevent the flow of gas that has collided with the blocking surface of the first member 21 from heading toward the tip of the first member 21 and then toward the outside of the pot. Therefore, as compared with the case of the shape of the basic configuration shown in FIG. 1, it is possible to more reliably block or reduce the flow of gas toward the outside of the pot.

The second member 23 provided at the tip of the first member 21 is preferably provided so as to be inclined in an angle range of 90 ° or less, which is larger than 0 ° toward the steel strip S side with respect to the extending direction of the first member 21. .. In a state where the second member 23 is provided parallel to the extending direction of the first member 21 (that is, 0 °), it may be considered as a part of the first member 21. Further, if the second member 23 is provided so as to face the outer side of the pot 11 with respect to the extending direction of the first member 21, the flow of the gas blown up at the edge portion 11a of the pot 11 is promoted to the outside of the pot. The amount of metal powder generated on the steel strip S side flowing out of the pot increases. Further, when the second member 23 is provided by bending the steel strip S side by more than 90 ° with respect to the extending direction of the first member 21, the gas flow from the plating bath toward the blocking member 20b is made to flow to the first member. There is a possibility that the second member 23 is directed to the outside without colliding with the blocking surface of the 21. Then, the gas from the plating bath toward the edge portion 11a of the pot 11 may blow up through the upper part of the second member 23, and the metal powder generated on the steel strip S side may be scattered to the outside of the pot.

The length a of the second member 23 is not particularly limited, but if it is too short, the effect of blocking or reducing the gas flow is almost the same as that of the basic configuration shown in FIG. Further, if the length a of the second member 23 is too long, it covers the bath of the plating bath 3, which lowers the workability of the operator. Therefore, the length of the second member 23a is preferably set so as to be within the range of the edge region including the edge portion 11a of the pot 11.

The blocking member 20c installed at the pot edge of the continuous molten metal plating apparatus shown in FIG. 3 is provided on the front surface of the pot 11 at the edge 11a. The blocking member 20c is provided vertically from the front surface of the pot 11 toward the steel strip S side. Also in this case, the blocking member 20c is provided so as to be inclined by a predetermined inclination angle θ from the vertical or vertical state to the bath surface of the plating bath 3 toward the steel strip S side. The inclination angle θ is preferably 90 ° or less. Further, the height h of the blocking member 20c is preferably set to 200 mm or more and 400 mm or less so as to be within the range of the edge region including the edge 11a of the pot 11. As a result, the flow of gas toward the outside of the pot can be blocked or reduced in the same manner as in the case of the shape of the basic configuration shown in FIG.

In the example shown in FIGS. 1 to 3, the edge region of the pot 11 provided with the blocking members 20a to 20c has a shape in which the upper surface on the outer side of the edge portion 11a, which is the inner portion, projects upward. However, the shape and installation position of the blocking member do not depend on the shape of the edge region. For example, as shown in FIG. 4, even when the outer upper surface of the edge portion 11a of the pot 11 is a horizontal horizontal plane 11c, the position of the steel strip side 100 mm with respect to the edge portion 11a which is the front surface of the pot 11. The blocking member 20d may be provided in the region from the to the outer side to the position of 100 mm.

At this time, the blocking member 20d is provided so as to be inclined by a predetermined inclination angle θ from the vertical or vertical state with respect to the bath surface of the plating bath 3 to the steel strip S side. The inclination angle θ is preferably 90 ° or less. Further, the height h of the blocking member 20c is preferably set to 200 mm or more and 400 mm or less so as to be within the range of the edge region including the edge 11a of the pot 11. Further, as shown in FIG. 2, an additional member that bends toward the steel strip S side may be provided at the tip of the blocking member 20d. In the example of FIG. 4, the blocking member 20d is provided at the corner between the edge portion 11a and the horizontal plane 11c of the pot 11, but it may be attached to the edge portion 11a as shown in FIG. 3, and is attached to the horizontal plane 11c. You may.

[2-2. Second form (installation near steel strip)]
Next, one form of the blocking member included in the continuous molten metal plating apparatus according to the embodiment of the present invention will be described with reference to FIGS. 5 and 6. 5 and 6 are explanatory views showing an example of a form of a blocking member installed near a steel strip of the continuous molten metal plating apparatus according to the present embodiment. In addition, also in FIG. 5 and FIG. 6, the blocking member may be installed at least in front of the pot 11.

The blocking member according to the second embodiment blocks the flow of gas from the steel strip S side toward the edge portion 11a of the pot 11 in the vicinity of the steel strip S, and prevents metal powder from scattering to the outside of the pot 11. As described above, the metal powder generated at the lower part of the slit nozzle 15 of the gas wiping device rides on the gas flowing on the plating bath from the steel strip side toward the edge 11a of the pot 11 and goes to the outside of the pot 11. Scatter. Therefore, in the second embodiment, the flow of gas toward the plating bath is blocked or reduced by arranging the blocking member in the region where the steel strip S flows out onto the plating bath.

(1) Basic Configuration First, based on FIG. 5, a basic configuration of a blocking member installed in the vicinity of the steel strip S to be plated by the continuous molten metal plating apparatus will be described. As shown in FIG. 5, the continuous molten metal plating apparatus includes a blocking member 30a installed facing the steel strip S pulled up from the molten metal plating bath 3. The blocking member 30a is a plate-shaped member extending in the depth direction of the paper surface of FIG. 5, and is formed of a heat-resistant member having a melting point higher than the temperature of the molten metal plating bath 3. For example, the blocking member 30a is formed of a steel plate. The blocking member 30a may be a plate-shaped member having no through hole so that the gas flow can be completely blocked. Alternatively, the blocking member 30a may be, for example, a mesh-like plate-shaped member having fine through holes formed, as long as the gas flow can be reduced at least. Since the gas flow from the steel strip S side toward the edge portion 11a of the pot 11 occurs over the entire width of the steel strip S, the blocking member 30a has a length equal to or longer than the width of the steel strip S in the depth direction of the paper surface of FIG. It is arranged so as to face the band S.

In the present embodiment, the blocking member 30a is installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip S in the direction from the surface of the steel strip S toward the front surface which is the edge portion 11a of the pot 11. If the distance d from the steel strip S to the blocking member 30a is smaller than 50 mm, the blocking member 30a may come into contact with the steel strip S. In order to reliably avoid contact with the steel strip S, the distance d from the steel strip S to the blocking member 30a is preferably 100 mm or more. On the other hand, when the distance d from the steel strip S to the blocking member 30a is larger than 200 mm, the gas flow from the surface of the steel strip S to the edge portion 11a of the pot 11 cannot be effectively blocked or reduced. The blocking member 30a is installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip S.

Further, the blocking member 30a has a length h of 100 mm or more and 200 mm or less in the vertical direction, and the lower end 31a of the blocking member 30a is at a height position h ₀ of 0 mm or more and 20 mm or less from the bath surface of the molten metal plating bath 3. Will be installed. If the length h of the blocking member 30a is shorter than 100 mm, the effect of suppressing the gas flow from the surface of the steel strip S to the edge portion 11a of the pot 11 is small, and the flow is not sufficiently weakened. The metal powder generated in the vicinity of S scatters to the outside of the pot 11 along with the gas flow. On the other hand, when the length h of the blocking member 30a is longer than 200 mm, the gas flow generated between the surface of the steel strip S and the blocking surface of the blocking member 30a affects the gas flow injected by the slit nozzle 15. Will affect the adjustment of the amount of molten metal adhering to the surface of the steel strip S by gas wiping.

That is, as shown in FIG. 5, the gas flow generated in the vicinity of the steel strip S goes vertically downward from the slit nozzle 15 toward the plating bath 3 and then hits the blocking surface of the blocking member 30a, and the flow of the gas flows. Change the orientation vertically upward. At this time, if the length h of the blocking member 30a is longer than 200 mm, the gas flows to the vicinity of the slit nozzle 15 without weakening the gas flow vertically upward, and as a result, the steel strip S from the slit nozzle 15 It collides with the flow of gas injected to the surface of the steel and reduces the wiping performance. Therefore, the length h of the blocking member 30a is preferably 100 mm or more and 200 mm or less.

The lower end 31a of the blocking member 30a is installed so as to be located between the bath surface 3a of the plating bath 3 up to a predetermined height position h _0. Specifically, the height position h ₀ is preferably 20 mm or less. When the height position h ₀ is made larger than 20 mm, the gas directed from the surface of the steel strip S toward the edge 11a of the pot 11 passes through the gap between the bath surface 3a and the lower end 31a of the blocking member 30a, and the edge of the pot 11 It flows to the part 11a. Therefore, by providing the lower end 31a of the blocking member 30a so as to be in contact with the bath surface 3a, or by setting the gap between the bath surface 3a and the lower end 31a of the blocking member 30a to 20 mm or less, the pot can be formed from the surface of the steel strip S. The flow of gas toward the edge 11a of 11 can be blocked or reduced.

As described above, by providing the blocking member 30a in the vicinity of the steel strip S to be plated by the continuous molten metal plating apparatus, the gas flow from the steel strip S side to the edge portion 11a of the pot 11 can be flowed to the steel strip S. It shuts off in the vicinity of the pot 11 to prevent the metal powder from scattering to the outside of the pot 11. As a result, the workability of the operator working around the pot 11 of the continuous molten metal plating apparatus is not deteriorated, and the molten metal plating process can be continuously operated.

(2) Deformation Example FIG. 6 shows a modification of the blocking member of the second form. The blocking member 30b installed in the vicinity of the steel strip S to be plated by the continuous molten metal plating apparatus shown in FIG. 6 includes a first member 31 corresponding to the blocking member 30a having the basic configuration shown in FIG. It is composed of a second member 33 and a third member 35, which are additional members provided at the tip of the member 31 and bent toward the steel strip S side. By providing such an additional member, it is possible to prevent the gas flow vertically upward from colliding with the blocking surface of the first member 31 from colliding with the additional member and affecting the gas injection of the slit nozzle 15. Can be done. Therefore, as compared with the case of the basic configuration shown in FIG. 5, in addition to blocking or reducing the flow of gas toward the outside of the pot, it is possible to eliminate the influence on the gas injection of the slit nozzle 15.

Specifically, the additional members (second member 33 and third member 35) provided at the tip of the first member 31 are bent toward the steel strip S side with respect to the extending direction of the first member 31. There is. With such a shape, the gas flow that collides with the blocking surface of the first member 31 and goes vertically upward can be effectively blocked by the additional member. In the example shown in FIG. 6, the additional member is configured by combining two plate-shaped members of the second member 33 and the third member 35 so as to form a space covering the gas flow. Is not limited to such an example. For example, the side surface shape of the additional member may be a semicircular shape, a rectangular shape, or the like, in addition to the V-order shape as shown in FIG.

The length of the additional member is not particularly limited, but if it is too short, the effect of blocking or reducing the gas flow is almost the same as that of the basic configuration shown in FIG. Further, if the length of the additional member is too long, it may come into contact with the steel strip S. Therefore, the additional member should be provided at a distance of 50 mm or more from the surface of the steel strip S.

Further, the blocking member of the second form does not necessarily have to be provided perpendicular to the bath surface of the plating bath 3, and if the gas flow from the steel strip S side to the edge portion 11a of the pot 11 can be blocked. It may be tilted from a state perpendicular to the bath surface.

<3. Summary>
The continuous molten metal plating apparatus according to the embodiment of the present invention has been described above. In the continuous molten metal plating apparatus according to the present embodiment, the metal powder generated at the lower part of the slit nozzle 15 scatters to the outside of the pot 11 on the gas flow from the steel strip S side toward the edge 11a of the pot 11. Provide a blocking member to prevent it. The blocking member is arranged between the steel strip S and the edge region including the edge portion 11a of the pot 11, and blocks the flow of gas from the steel strip S side toward the edge portion 11a of the pot 11. As a result, the flow of this gas can be reduced, and the amount of metal powder scattered to the outside of the pot 11 can be reduced.

In order to verify the effect of the continuous molten metal plating apparatus of the present invention, a simulation was performed on the amount of metal powder scattered to the outside of the pot of the continuous molten metal plating apparatus. In this simulation, in a continuous molten metal plating apparatus that performs zinc plating, the plate passing speed was set to 200 mpm, and the amount of metal powder (zinc powder) scattered to the outside of the pot and the workability of the operator were evaluated. Regarding the amount of metal powder scattered to the outside of the pot, the amount of metal powder scattered to the outside of the pot is based on the amount of metal powder scattered to the outside of the pot when the blocking member for blocking the scattering of the metal powder to the outside of the pot is not provided. When the amount of scattering can be reduced by 50% or more from the standard, it is evaluated as "○", when it can be reduced by 11 to 49% from the standard, it is evaluated as "△", and when the amount of reduction from the standard is 10% or less, it is evaluated as "×". bottom. In addition, the workability of the operator is "○" when the operator can work as in the case where the blocking member is not installed, and the workability is lower than when the blocking member is not installed. However, when the operator's work was possible, it was evaluated as "Δ", and when the operator's work was hindered, it was evaluated as "x". Tables 1 and 2 below show the simulation setting conditions and evaluation results.

Table 1 shows the simulation results of Examples A1 to A8 in the case where the blocking member is installed at the edge of the pot in the continuous molten metal plating apparatus according to the above embodiment. That is, Examples A1 to A8 in Table 1 correspond to the configurations shown in FIGS. 1 to 4, and the metal powder to the outside of the pot is changed by changing the distance, the height h, and the inclination angle θ from the pot edge portion 11a. The amount of scattering and the workability of the operator were evaluated. The distance from the pot edge 11a is represented by a negative value on the steel strip side and a positive value on the pot outer side with reference to the pot edge 11a. As a comparative example, the same evaluation was performed in the case where the blocking member was not provided.

In Examples A1 to A5, the blocking member was installed between the edge regions from the position 100 mm on the steel strip side from the edge of the pot to the position 100 mm on the outer side from the edge of the pot. As a result, in each of Examples A1 to A5, the amount of metal powder scattered to the outside of the pot can be reduced by 50% or more from the standard without deteriorating the workability of the operator by installing the blocking member. rice field.

In Example A6, the blocking member was installed between the edge regions, but the height h of the blocking member was shorter than 200 mm. Therefore, the amount of metal powder scattered to the outside of the pot increased as compared with Examples A1 to A5, but there was an acceptable suppressing effect. In addition, it did not interfere with the work of the operator.

In Example A7, the height h of the blocking member was longer than 400 mm, and the tip portion protruded from the edge region. In this case, the workability of the operator is reduced, but the amount of metal powder scattered to the outside of the pot can be reduced.

In Example A8, the inclination angle θ of the blocking member was larger than 90 °, and the tip portion protruded from the edge region. In this case, the amount of metal powder scattered to the outside of the pot was increased as compared with Examples A1 to A5, but there was an acceptable suppressing effect. In addition, the workability of the operator was reduced, but the work was possible.

On the other hand, in the comparative example, since the blocking member is not provided, the operator's work is not hindered, but the result is that the amount of metal powder scattered to the outside of the pot is large.

Next, Table 2 shows the simulation results in the case where the blocking member is installed in the vicinity of the steel strip in the continuous molten metal plating apparatus according to the above embodiment as Examples B1 to B12. That is, examples B1~B12 in Table 2 corresponds to the configuration shown in FIGS. 5 and 6, the distance from the steel strip surface d, height h, by changing the height position h ₀ from the bath surface, The amount of metal powder scattered to the outside of the pot and the workability of the operator were evaluated. The blocking member was provided perpendicular to the bath surface. As a comparative example, as in Table 1, the same evaluation was performed in the case where the blocking member was not provided.

In Examples B1 to B6, the blocking member was installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip. The length of the blocking member in the vertical direction is 100 mm or more and 200 mm or less, and the lower end of the blocking member is installed so as to be at a height of 0 mm or more and 20 mm or less from the bath surface of the molten metal plating bath. As a result, in each of Examples B1 to B6, the amount of metal powder scattered to the outside of the pot can be reduced by 50% or more from the standard without deteriorating the workability of the operator by installing the blocking member. rice field.

In Example B7, the blocking member was installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip, but the height h was smaller than 100 mm. Therefore, the amount of metal powder scattered to the outside of the pot increased as compared with Examples B1 to B6, but there was an acceptable suppressing effect. In addition, it did not interfere with the work of the operator. On the other hand, in Example B8, the blocking member was installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip, but the height h was larger than 200 mm. In this case, the workability of the operator is lowered, but the amount of metal powder scattered to the outside of the pot can be reduced.

In Example B9, the blocking member is installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip, and the height h is also 100 mm or more and 200 mm or less, but the height position h ₀ from the bath surface is larger than 20 mm. rice field. In this case, the amount of metal powder scattered to the outside of the pot was increased as compared with Examples B1 to B6, but there was an acceptable suppressing effect. In addition, it did not interfere with the work of the operator.

In Examples B10 and B11, the height h of the blocking member and the height position h ₀ from the bath surface satisfy the above requirements, but in Example B10, the installation position is closer than 50 mm from the surface of the steel strip. In Example B11, the position was more than 200 mm away from the surface of the steel strip. In this case, the workability of the operator is reduced, but the amount of metal powder scattered to the outside of the pot can be reduced.

In Example B12, the blocking member satisfied the above requirements for the height h, but was separated from the surface of the steel strip by more than 200 mm, and the height position h ₀ from the bath surface was larger than 20 mm. .. In this case, the amount of metal powder scattered to the outside of the pot was increased as compared with Examples B1 to B6, and the workability of the operator was also lowered, but there was an acceptable suppressing effect.

On the other hand, in the comparative example, since the blocking member is not provided, the operator's work is not hindered, but the result is that the amount of metal powder scattered to the outside of the pot is large.

In addition, FIG. 8 shows the simulation results of the airflow on the bath and in the vicinity of the edge of the pot. Example A is a simulation result when a blocking member is installed at the edge of the pot, and Example B is a simulation result when a blocking member is installed near the steel strip. In the A embodiment, the blocking member is installed between the edge region from the position 100 mm on the steel strip side from the edge of the pot to the position 100 mm on the outer side from the edge of the pot. In Example B, the blocking member is installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip, the length in the vertical direction is 100 mm or more and 200 mm or less, and the lower end of the blocking member is a bath of a molten metal plating bath. It is installed so that it is at a height of 0 mm or more and 20 mm or less from the surface. Further, as a comparative example, a simulation result when the blocking member is not provided is shown.

From FIG. 8, as a comparative example, it can be seen that when the blocking member is not provided, the flow on the bath surface from the surface of the steel strip toward the pot edge side (left side of the paper surface) is vigorously blown up to the outside of the pot as it is. .. On the other hand, in Examples A and B, the flow on the bath surface from the surface of the steel strip toward the pot edge side (left side of the paper surface) becomes a flow returning to the steel strip side at the installation position of the blocking member, and from the pot edge portion. The flow to the outside is suppressed. From this simulation result, it can be seen that the scattering of the metal powder to the outside of the pot can be suppressed by providing the blocking member as in the present invention.

Table 3 shows the verification results of the influence when the blocking member is provided with the through hole. The blocking member of Example C4 was the same as the blocking member of Example A5, and the blocking member of Examples C1 to C3 was provided with a circular through hole in the blocking member of Example A5 and had a mesh structure. The diameters (mesh diameters) of the through holes provided in Examples C1 to C3 had average values of diameters corresponding to circles of 307 μm, 398 μm, and 498 μm, respectively. The diameter of the through holes is a value obtained by randomly extracting 20 through holes from a plurality of through holes and averaging their diameters. Then, with respect to Examples C1 to C4, the amount of metal powder scattered to the outside of the pot and the workability of the operator were evaluated based on the same criteria as described above, and the presence or absence of metal powder scattered in the width direction of the pot was evaluated. Regarding the scattering of metal powder in the width direction of the pot, regardless of whether the metal powder is scattered outside the pot, the case where the metal powder is scattered in the width direction of the pot is "Yes", and the metal powder is scattered in the width direction of the pot. The case where was not scattered was evaluated as "none".

From Table 3 below, in Example C1 having a mesh diameter of 307 μm and Example C2 having a mesh diameter of 398 μm, the amount of metal powder scattered to the outside of the pot without deteriorating the workability of the operator by installing the blocking member. Was reduced by 50% or more from the standard. In Examples C1 and C2, no scattering of metal powder was confirmed in the pot width direction.

In Example C3 having a mesh diameter of 498 μm, the installation of the blocking member did not reduce the workability of the operator, but a part of the metal powder passed through the through hole of the blocking member and scattered to the outside of the pot. In Example C3, the effect of suppressing and reducing metal powder scattering was lower than that in Examples 1 and 2, but scattering of metal powder in the width direction of the pot was not confirmed.

Further, in Example C4 in which the blocking member is not formed with a through hole, the amount of metal powder scattered to the outside of the pot can be reduced by 50% or more from the standard without deteriorating the workability of the operator by installing the blocking member. It was possible to obtain a large effect of suppressing the scattering of metal powder. However, in Example C4, the metal powder was scattered in the width direction of the pot.

Based on these results, by configuring as in Examples C1 and C2, it is possible to both suppress the scattering of metal powder to the outside of the pot and maintain the workability of the operator, and to obtain the metal powder in the width direction of the pot. Scattering can also be reliably suppressed.

From the above, it has been shown that by configuring the continuous molten metal plating apparatus according to the above-described embodiment of the present invention, it is possible to suppress the scattering of metal powder to the outside of the pot and maintain the workability of the operator.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

3 Molten metal plating bath 3a Bath surface 5 Molten metal 10 Continuous molten metal plating equipment 11 Pot 11a Edge 11b Mounting surface 11c Horizontal surface 13 Bath roll 15 Slit nozzle 20a, 20b, 20c, 20d, 30a, 30b Blocking member

Claims (10)

Gas is sprayed by a gas wiping device onto a steel strip pulled upward at a plate passing speed of 150 mpm or more from a molten metal plating bath housed in a pot, and molten metal having a predetermined thickness is adhered to the surface of the steel strip. In continuous molten metal plating equipment
A blocking member for blocking the flow on the plating bath that blows up from the steel strip toward the edge of the pot as the steel strip pulled up from the molten metal plating bath is provided.
The blocking member is
Arranged between the steel strip and the edge region including the edge of the pot ,
Installed between the edge region from the position 100 mm on the steel strip side to the position 100 mm on the outer side from the edge of the pot in the direction from the surface of the steel strip toward the front surface of the pot. It is Ru, continuous molten metal plating apparatus. The blocking member is attached to the pot in the edge region of the pot.
The continuous molten metal plating apparatus according to claim 1 , wherein the height of the blocking member from the mounting surface to the pot is 200 mm or more and 400 mm or less. Gas is sprayed by a gas wiping device onto a steel strip pulled upward at a plate passing speed of 150 mpm or more from a molten metal plating bath housed in a pot, and molten metal having a predetermined thickness is adhered to the surface of the steel strip. In continuous molten metal plating equipment
A blocking member for blocking the flow on the plating bath that blows up from the steel strip toward the edge of the pot as the steel strip pulled up from the molten metal plating bath is provided.
The blocking member is
It consists of a mesh-like plate-like member with multiple through holes formed.
The through hole is formed so that the average value of the diameters corresponding to the circle is 300 μm or more and 400 μm or less.
A continuous molten metal plating apparatus arranged between the steel strip and the edge region including the edge of the pot. The blocking member according to any one of claims 1 to 3, wherein the blocking member is installed in a region of 50 mm or more and 200 mm or less from the surface of the steel strip in a direction from the surface of the steel strip toward the front surface of the pot. Continuous molten metal plating equipment. The blocking member is
The length in the vertical direction is 100 mm or more and 200 mm or less.
The continuous molten metal plating apparatus according to claim 4, wherein the lower end of the blocking member is installed so as to be at a height of 0 mm or more and 20 mm or less from the bath surface of the molten metal plating bath. The continuous melting according to any one of claims 1 to 5, wherein the blocking member is provided perpendicular to the bath surface of the plating bath or inclined from the vertical state to the steel strip side at a predetermined inclination angle. Metal plating equipment. The continuous molten metal plating apparatus according to any one of claims 1 to 6, wherein the blocking member is arranged so that the blocking surface of the blocking member is arranged so as to be substantially orthogonal to the flow. The continuous molten metal plating apparatus according to any one of claims 1 to 7, wherein an additional member that bends on the steel strip side is provided at the tip of the blocking member. The continuous molten metal plating apparatus according to any one of claims 1 to 8, wherein the width of the blocking member is larger than the width of the steel strip. In a continuous molten metal plating apparatus that adheres molten metal of a predetermined thickness to the surface of a steel strip, gas is pulled upward from the molten metal plating bath contained in the pot at a plate passing speed of 150 mpm or more. Blow gas with a wiping device,
The flow on the plating bath that blows up from the steel strip toward the edge of the pot with the movement of the steel strip pulled up from the molten metal plating bath, and the edge region including the edge of the pot from the steel strip. From the position 100 mm on the steel strip side from the edge of the pot to the position 100 mm on the outer side from the edge of the pot in the direction from the surface of the steel strip to the front surface of the pot. A continuous molten metal plating treatment method in which a blocking member installed between the edge regions blocks the material.

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