JP2016074944A - Hot-dip metal plating apparatus and method for removing impurity of hot-dip metal plating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot-dip metal plating apparatus capable of suppressing the occurrence of poor quality of a hot-dip metal plated steel sheet, and a method for removing impurities of the hot-dip metal plating apparatus.SOLUTION: A hot-dip metal plating apparatus comprises: a surface deposit removing part 10 (11, 12 and 13) for pressing polishing parts 11b, 12b and 13b on the surfaces of a sink roll 4 and a pair of support rolls 5 and 6 to remove surface deposits deposited on the surface of the sink roll 4 and the pair of support rolls 5 and 6; and an impurity suction removing part 20 for sucking a hot-dip metal plating liquid 2 through suction pipes 21, 22 and 23 having suction openings 21a, 22a and 23a in upstream side regions E1-E3 of contact portions formed by contacting a steel strip S with the sink roll 4 and the pair of support rolls 5 and 6 to remove impurities.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a molten metal plating apparatus that guides a strip-shaped member to be plated into a molten metal plating solution using a roll and continuously forms a molten metal film on the strip-shaped member, and an impurity removal method for the molten metal plating apparatus. .

  Conventionally, in a molten metal plating apparatus for continuously producing a molten metal plated steel sheet, a steel strip is continuously supplied into a plating tank filled with a molten metal plating solution. The sink roll disposed in the plating tank guides the steel strip to a deep portion in the plating tank, and changes the traveling direction of the steel strip from the inside of the plating tank vertically upward. A hot-dip plating layer is formed on the steel strip whose direction has been changed, and is pulled up above the plating tank.

  In the plating tank, a pair of support rolls are arranged for stabilizing the pulling position of the steel strip whose direction has been vertically changed by the sink roll and for suppressing the warpage of the steel strip.

  In the above-described molten metal plating apparatus, when continuous molten metal plating is performed on a steel strip, a part of the molten metal plating solution is oxidized to produce impurities (dross), and these impurities are suspended in the molten metal plating solution. . When the suspended impurities adhere to the surface of the roll, they are transferred to a steel strip that comes into contact with the roll. The transfer of the impurities to the steel strip becomes a defect such as a pressing rod with respect to the molten metal plated steel plate.

  For this reason, in patent document 1, the grinding | polishing part which contacts the surface of the roll arrange | positioned in a molten metal plating bath is provided, and the surface deposit | attachment adhering to the roll surface is removed. This polishing part removes surface deposits on the entire roll surface by traversing in the axial direction of the roll as the roll rotates. Further, the polishing unit is heated so that the heating amount is changed according to the rotation speed of the roll.

JP 2013-76111 A

  However, even if the deposit on the roll surface is removed by the polishing section, the removed deposit will float in the molten metal plating bath. This floating deposit adheres to the molten metal plated steel sheet in the same manner as the impurities in the molten metal plating solution. As a result, defects are produced in the manufactured molten metal plated steel sheet.

  This invention is made in view of the above, Comprising: It aims at providing the impurity removal method of the molten metal plating apparatus and molten metal plating apparatus which can suppress generation | occurrence | production of the quality defect of a molten metal plating steel plate. .

  In order to solve the above-described problems and achieve the object, a molten metal plating apparatus according to the present invention uses a roll to guide a strip-shaped member to be plated into a molten metal plating solution and continuously to the strip-shaped member. A molten metal plating apparatus for forming a molten metal film, wherein a surface adhering substance removing unit that removes a surface adhering substance adhering to the surface of the roll by pressing a polishing part on the surface of the roll, And an impurity suction removal unit that removes impurities by sucking the molten metal plating solution through a suction tube provided with a suction opening on the upstream side of the contact part in contact with the roll.

  Further, in the molten metal plating apparatus according to the present invention, in the above invention, the roll includes a sink roll for guiding the band-shaped member into the molten metal plating tank, and a band-shaped member from the molten metal plating tank via the sink roll. A pair of support rolls for guiding the drawer, wherein the sink roll and the pair of support rolls are provided on the upstream side of the contact portion in contact with the belt-like member, respectively.

  In the molten metal plating apparatus according to the present invention as set forth in the invention described above, the surface deposit removing part is traversed in the axial direction of the roll while pressing the polishing part against the roll as the roll rotates. Removing the surface deposits adhering to the surface of the roll, and when the load applied to the polishing unit is a predetermined value or more, the traversing of the polishing unit is stopped to remove the surface deposits. .

  In the molten metal plating apparatus according to the present invention as set forth in the invention described above, the surface deposit removing part heats the polishing section to remove the surface deposit.

  Moreover, the impurity removal method of the molten metal plating apparatus concerning this invention is the molten metal which guides the strip | belt-shaped member to be plated into a molten metal plating solution using a roll, and forms a molten metal film | membrane continuously on the said strip | belt-shaped member. An impurity removal method for a plating apparatus, wherein a polishing portion is pressed against the surface of the roll to remove surface deposits adhering to the surface of the roll, and upstream of the contact portion where the belt-shaped member and the roll are in contact with each other An impurity is removed by sucking a molten metal plating solution through a suction tube provided with a suction opening.

  Moreover, the impurity removal method of the molten metal plating apparatus concerning this invention WHEREIN: When removing the surface deposit | attachment adhering to the surface of the said roll in said invention, the said grinding | polishing part is made into the said roll with rotation of the said roll. When the load applied to the polishing part is greater than or equal to a predetermined value, the surface of the polishing part is stopped and the movement of the polishing part is stopped. It is characterized by removing surface deposits.

  According to the present invention, the polishing portion is pressed against the surface of the roll to remove surface deposits attached to the surface of the roll, and a suction opening is provided upstream of the contact portion where the strip-shaped member to be plated contacts the roll. Impurities are removed by sucking the molten metal plating solution through a suction tube provided with a. As a result, the removed surface deposit is efficiently removed before floating in the molten plating solution, and the impurities in the molten metal plating solution are removed before being transferred to the belt-like member at the contact portion. In addition, it is possible to suppress the occurrence of poor quality of the molten metal plated steel sheet that is a plated strip-shaped member.

FIG. 1 is a schematic diagram showing an overall configuration of a molten metal plating apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view of the detailed configuration of the surface deposit removal unit shown in FIG. 1 as viewed from the left side. FIG. 3 is a flowchart showing a surface deposit removal control processing procedure by the surface deposit removal control unit. FIG. 4 is a diagram illustrating a state in which surface deposits are removed by the polishing unit. FIG. 5 is a schematic diagram showing a configuration of a polishing unit and a blade having a heating mechanism.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

(Device configuration)
FIG. 1 is a schematic diagram showing an overall configuration of a molten metal plating apparatus 1 according to an embodiment of the present invention. As shown in FIG. 1, a molten metal plating apparatus 1 has a plating tank 3 filled with a molten metal plating solution 2. The molten metal plating solution 2 includes a sink roll 4 and a pair of support rolls 5 and 6. A steel strip S, which is a strip-shaped member to be plated, is supplied into the molten metal plating solution 2 via a snout 7 partially immersed in the molten metal plating solution 2. The steel strip S via the snout 7 enters obliquely up to the sink roll 4 provided in the deep part in the molten metal plating solution 2, and then is changed in the vertical direction by the sink roll 4. The steel strip S whose direction has been changed is guided by a pair of support rolls 5 and 6 provided in the molten metal plating solution so that the steel strip S is stable when the steel strip S is pulled up vertically and warpage is suppressed. Figured. In the present embodiment, molten zinc is used as an example of the molten metal. As the steel strip S passes through the molten metal plating solution 2, a molten metal film is formed on the front and back surfaces.

  The steel strip S pulled up vertically from the molten metal plating solution 2 is adjusted in amount of plating by the gas sprayed from the wiping nozzle 8 provided above the molten metal plating solution 2 and in the vertical lifting direction. Is done. Thereafter, the steel strip S whose plating adhesion amount is adjusted is heated in the alloying furnace 9 as necessary, and the plating layer is alloyed.

[Surface deposit removal part]
The surface deposit removal unit 10 includes three surface deposit removal units 11 to 13. The surface deposit removal unit 11 removes surface deposits that adhere to the surface of the sink roll 4. Further, the surface deposit removal parts 12 and 13 remove the surface deposits adhering to the surfaces of the support rolls 5 and 6, respectively. The surface deposit removal parts 11 to 13 remove the surface deposits by polishing the surfaces of the rotating rolls by the polishing units 11b, 12b, and 13b provided at the tips of the blades 11a, 12a, and 13a, respectively. The detailed configuration will be described later.

[Impurity removal part]
The impurity suction removing unit 20 has three suction tubes 21 to 23. The suction opening 21a of the suction pipe 21 is provided in the upstream region E1 of the contact portion where the steel strip S and the sink roll 4 are in contact. The suction openings 22a and 23a of the suction pipes 22 and 23 are provided in the upstream areas E2 and E3 of the contact portions where the steel strip S and the support rolls 5 and 6 are in contact with each other.

  The suction pipes 21 to 23 are connected to the suction pump P. The suction pump P sucks the molten metal plating solution 2 in the upstream regions E1 to E3 through the suction openings 21a, 22a, and 23a and discharges it to the tank T. The tank T is partitioned by a partition plate 24 having a depth that allows the sucked molten metal plating solution 2 to pass therethrough, and a filter 25 is provided in one region. The suction pump P supplies the sucked molten metal plating solution 2 to the other region where the filter 25 is not provided. The molten metal plating solution 2 that has moved beyond the partition plate 24 and moved to one region where the filter 25 is provided is freed of impurities by the filter 25 and returned to the plating bath 3 again as a clean molten metal plating solution 2. . The impurity suction removal controller C2 of the controller C controls the suction pump P to control the suction amount from each suction opening 21a, 22a, 23a.

  In the upstream regions E1 to E3, as the steel strip S moves, flows F1 to F3 of the molten metal plating solution 2 along the traveling direction of the steel strip S are generated, and the flows F1 to F3 are the sink roll 4 or the support roll. This is a region where impurities are blown and accumulated near the upstream side of the contact portions 5 and 6. Further, the upstream regions E1 to E3 are upstream of the contact portion between the steel strip S and the sink roll 4 or the support rolls 5 and 6, and impurities existing in this region may be transferred to the steel strip S. Is expensive. Therefore, the impurities of the molten metal plating solution 2 in the plating tank 3 can be efficiently removed by sucking the molten metal plating solution 2 in the upstream regions E1 to E3 through the suction openings 21a, 22a, and 23a. At the same time, the transfer of impurities to the steel strip S can be suppressed. Further, the suction openings 21a, 22a and 23a are located in the vicinity of the sink roll 4, the support rolls 5 and 6 where the surface deposit removal parts 11, 12, and 13 remove the surface deposit, and thus the removed surface deposits. Is efficiently sucked and removed before it diffuses into the molten metal plating solution 2.

  In addition, since many impurities float near the snout 7, a suction opening is provided at the output end of the snout 7 or below the liquid surface in the snout 7, and the molten metal plating solution 2 is sucked to remove the impurities. Also good.

[Detailed configuration of surface deposit removal unit]
FIG. 2 is a schematic view of the detailed configuration of the surface deposit removal unit 11 shown in FIG. 1 as viewed from the left side. As shown in FIG. 2, the surface deposit removing unit 11 removes the surface deposit by polishing the surface of the rotating sink roll 4 with the polishing unit 11 b provided at the tip of the blade 11 a as described above. . The sink roll 4 is supported by a roll support member 4 b provided at the upper end of the plating tank 3. One end of the roll support member 4 b has a flange extending into the plating tank 3, and the front ends of the flanges of the two roll support members 4 b rotatably support the rotation shafts 4 a at both ends of the sink roll 4. The rotating shaft 4a is parallel to the Y-axis direction.

  The polishing portion 11b is made of a metal material having durability against molten metal, and is made of, for example, stainless steel. The polishing unit 11b includes a grinding function for cutting with a blade-like shape in addition to the function for polishing.

  The base end side of the blade 11 a is attached to the blade pressing portion 14. The blade pressing portion 14 has an air cylinder (not shown) that displaces the blade 11a in the axial direction A1 (Z direction). The air cylinder has a spring member having an elastic force in a direction in which the blade 11 a is separated from the sink roll 4. In addition, the air cylinder is connected to a compressor (not shown), for example, and the compressed air supplied from the compressor is fed into the air cylinder so that the blade 11a is sink-rolled against the elastic force of the spring member in the + Z direction. Displace to 4 side. Then, the air cylinder presses the polishing part 11 b against the sink roll 4 by the compressed air. The blade pressing unit 14 is connected to the surface deposit removal control unit C1 shown in FIG. The surface deposit removal control unit C1 controls the pressing force of the polishing unit 11b on the sink roll 4.

  The blade pressing portion 14 is connected to the ball screw mechanism 15. When the ball screw 16 rotates about the Y axis, the ball screw mechanism 15 moves a nut 17 provided on the blade pressing portion 14 in the Y axis direction. One end of the ball screw 16 is connected to the motor 18 to rotate the ball screw 16. The motor 18 is connected to the surface deposit removal controller C1 of the controller C shown in FIG. The surface deposit removal control unit C1 repeats the clockwise and counterclockwise rotations of the ball screw 16, and causes the polishing unit 1b to traverse in the axial direction A2 (Y-axis direction) of the sink roll 4 while pressing the surface of the sink roll 4. Take control.

[Surface deposit removal control processing of the surface deposit removal unit]
Here, with reference to the flowchart shown in FIG. 3, the surface deposit removal control processing procedure by the surface deposit removal controller C1 will be described. As shown in FIG. 3, the surface deposit removal control unit C1 first causes the blade 11a to traverse with a predetermined pressing force (step S101). The predetermined pressing force against the blade 11a presses the surface of the sink roll 4 with the predetermined pressing force against the polishing portion 11b via the blade pressing portion 14. The pressing force may be appropriately selected depending on the material of the roll or blade. Further, the traversing of the blade 11 a causes the polishing unit 11 b to traverse the surface of the sink roll 4 via the motor 18. For example, as shown in FIG. 4A, the polishing unit 11b travels in a zigzag manner on the surface of the sink roll 4 by traversing the surface while the sink roll 4 is rotating. Accordingly, the polishing unit 11b can uniformly polish the surface of the sink roll 4.

  Thereafter, the surface deposit removal controller C1 determines whether or not the motor load current value of the motor 18 exceeds a predetermined current value (step S102). When the motor load current value does not exceed the predetermined current value (No at Step S102), the process proceeds to Step S101, and the impurities are removed by traversing the polishing unit 11b described above. On the other hand, when the motor load current value exceeds the predetermined current value (step S102, Yes), the traversing of the blade 11a is stopped (step S103). Thereafter, the pressing force corresponding to the magnitude of the motor load current value is increased (step S104). When the motor load current value exceeds the predetermined current value, as shown in FIG. 4B, the polishing unit 11b detects adhesion of a large impurity 101, and the polishing unit 11b is stopped from traversing. Thus, the portion where the impurity 101 exists is removed. In this case, since the polishing unit 11b does not traverse in a zigzag manner, it is possible to perform polishing that removes impurities reliably and quickly each time the sink roll 4 rotates. The threshold value of the motor load current value may be appropriately selected depending on the motor capacity and the like.

  Thereafter, the surface deposit removal control unit C1 determines whether or not the motor load current value of the motor 18 has become equal to or less than a predetermined current value (step S105). When the motor load current value is not equal to or less than the predetermined current value (No at Step S105), the process proceeds to Step S104, and the impurities 101 are removed while the traversing of the polishing unit 11b is stopped. On the other hand, when the motor load current value is equal to or less than the predetermined current value (step S105, Yes), the process proceeds to step S101, where the traversing of the polishing unit 11b is resumed to remove impurities.

[Heating mechanism of polishing section]
In addition, you may have a heating mechanism which heats the grinding | polishing part 11b. For example, as shown in FIG. 5, a heating coil 32 may be provided in a portion where the polishing unit 11 b is connected to the blade 11 a, and the polishing unit 11 b may be heated by the heat source 31. In addition, when the heated polishing part 11b is pressed against the surface of the sink roll 4, the deposits containing aluminum dissolve and it is easy to remove impurities. The polishing unit 11b is provided with a temperature sensor 33 such as a thermocouple to detect the temperature of the polishing unit 11b. The surface deposit removal control unit C1 controls the heating amount based on the temperature detected by the temperature sensor 33, and controls the polishing unit 11b to be in a predetermined temperature range. As a result, as the rotational speed of the sink roll 4 increases, the amount of heating to the polishing unit 11b is controlled to increase.

DESCRIPTION OF SYMBOLS 1 Molten metal plating apparatus 2 Molten metal plating solution 3 Plating tank 4 Sink roll 4a Rotating shaft 4b Roll support member 5,6 Support roll 7 Snout 8 Wiping nozzle 9 Alloying furnace 10, 11, 12, 13 Surface deposit removal part 11a , 12a, 13a Blade 11b, 12b, 13b Polishing part 14 Blade pressing part 15 Ball screw mechanism 16 Ball screw 17 Nut 18 Motor 20 Impurity suction removal part 21, 22, 23 Suction tube 21a, 22a, 23a Suction opening 24 Partition plate 25 Filter 31 Heat source 32 Heating coil 33 Temperature sensor 101 Impurity A1, A2 Axial direction C1 Surface deposit removal control unit C2 Impurity suction removal control unit E1, E2, E3 Upstream region P Suction pump S Steel strip T Tank

Claims (6)

A molten metal plating apparatus for guiding a strip member to be plated into a molten metal plating solution using a roll and continuously forming a molten metal film on the strip member,
A surface deposit removal unit that removes surface deposits that adhere to the surface of the roll by pressing a polishing portion on the surface of the roll;
An impurity suction removal unit that removes impurities by sucking a molten metal plating solution through a suction tube provided with a suction opening on the upstream side of a contact portion where the belt-shaped member and the roll are in contact with each other;
A molten metal plating apparatus comprising: The rolls are a sink roll that guides the strip member into the molten metal plating tank, and a pair of support rolls that guide the withdrawal of the strip member from the molten metal plating tank via the sink roll,
2. The molten metal plating apparatus according to claim 1, wherein the suction opening is provided on an upstream side of a contact portion where the sink roll and the pair of support rolls are in contact with the belt-shaped member.   The surface deposit removal unit removes the surface deposit adhering to the surface of the roll while traversing in the axial direction of the roll while pressing the polishing unit against the roll as the roll rotates. 3. The molten metal plating apparatus according to claim 1, wherein when the load applied to the part is equal to or greater than a predetermined value, traversing of the polishing part is stopped and the surface deposits are removed.   The molten metal plating apparatus according to any one of claims 1 to 3, wherein the surface deposit removal unit heats the polishing unit to remove the surface deposit. A method for removing impurities in a molten metal plating apparatus that uses a roll to guide a strip-shaped member to be plated into a molten metal plating solution and continuously forms a molten metal film on the strip-shaped member,
A suction tube provided with a suction opening on the upstream side of the contact portion where the belt-shaped member and the roll come into contact with each other to remove surface deposits attached to the surface of the roll by pressing a polishing portion against the surface of the roll. An impurity removing method for a molten metal plating apparatus, wherein the molten metal plating solution is sucked through the metal to remove impurities.   When removing surface deposits adhering to the surface of the roll, the surface is attached to the surface of the roll by traversing in the axial direction of the roll while pressing the polishing portion against the roll as the roll rotates. The molten metal plating apparatus according to claim 5, wherein the kimono is removed, and when the load applied to the polishing unit is a predetermined value or more, traversing of the polishing unit is stopped and the surface deposit is removed. Impurity removal method.

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