KR100797842B1 - Electro-plating apparatus - Google Patents

Abstract

An electroplating apparatus is provided to produce a coated steel sheet from which surface defects are removed, and which is excellent in plating quality. An electroplating apparatus used to produce a Zn-Ni strip or a pure Zn strip comprises a carosel cell(10) including a first plating unit(110) which has a plurality of electrolytic cells(112,114,116,118) to plate one surface of a strip(S) and a second plating unit(130) which has a plurality of electrolytic cells(132,134,136,138) to plate the other surface of the strip, a horizontal cell(20) disposed in the rear of the carosel cell along a transfer path of the strip, wherein each of the electrolytic cells installed in the first and second plating units is used while flashing Ni to produce the pure Zn strip. The electrolytic cells each includes a conductor roll(120) and a pair of supporting rolls(122). The electroplating apparatus further comprises first and second temperature control parts(30,40) installed between the outlet side of the carosel cell and the inlet side of the horizontal cell.

Description

Electroplating Equipment {ELECTRO-PLATING APPARATUS}

1 is a schematic configuration diagram of an electroplating apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a main part configuration of a carousel cell provided in the electroplating apparatus of FIG. 1.

3 is a schematic view showing the configuration of main parts of a horizontal cell provided in the electroplating apparatus of FIG.

4 is a schematic view showing the configuration of main parts of the first temperature control unit provided in the electroplating apparatus of FIG. 1.

FIG. 5 is a schematic view showing the configuration of main parts of the second temperature control unit included in the electroplating apparatus of FIG. 1.

The present invention relates to an electroplating apparatus, and more particularly, to an electroplating apparatus for producing a zinc-based steel sheet (zinc-nickel steel sheet or pure zinc steel sheet) using a carousel cell and a horizontal cell.

Electroplating apparatuses used to produce zinc-based steel sheets, such as zinc-nickel steel sheets and pure zinc steel sheets, generally include a carousel cell and a horizontal cell.

The carousel cell is typically divided into first and second plating units, and after electroplating one side of the steel plate in the first plating unit, the other side of the steel plate is electroplated in the second plating unit.

Each electrolytic cell is provided with four electrolytic cell, and each electrolytic cell is provided with one roll set which consists of a pair of support rolls and a conductor roll.

The anode is provided at both ends of the lower end of the conductor roll and is deposited in the electrolyte solution in the electrolytic cell.

In this configuration, the carousel cell is electroplated with one surface of the steel plate opposite to the anode when the steel sheet drawn through the pair of support rolls passes through the anode while progressing by the rotation of the conductor roll.

Products that can be produced using the electroplating apparatus include zinc-nickel steel, pure zinc steel, and the like.

Here, the carousel cell consisting of the first and second plating units and having a total of eight roll sets is used to produce zinc-nickel steel sheet, and also for nickel flash in producing pure zinc steel sheet. Horizontal cells are used to conduct galvanizing when producing pure zinc steel sheets.

However, conventionally, when producing pure zinc steel sheet, all roll sets of carousel cells, that is, all 8 roll sets are used.

Therefore, surface defects such as foreign matters, roll marks, dent marks, etc. are generated in the strip, and power consumption is unnecessarily increased.

In addition, in order to produce high quality pure zinc steel sheet, it is important to lower the strip temperature (60 to 65 ° C) after passing through the carousel cell to 25 to 30 ° C and flow it into the horizontal cell.

Product No. Strip temperature (℃) Material thickness (mm) Material width (mm) Product defect One 60 0.6 1400 Occur 2 60 0.7 1400 Occur 3 60 0.8 1400 Occur 4 55 1.0 1500 Occur 5 50 1.2 1500 Occur 6 40 1.3 1500 Occur 7 40 0.8 1500 Occur 8 40 1.0 1400 Occur 9 40 1.1 1500 Occur 10 40 0.6 1500 Occur 11 40 0.7 1400 Occur 12 40 1.0 1500 Occur 13 30 1.1 1500 Not Occurred 14 30 0.6 1400 Not Occurred 15 30 0.7 1400 Not Occurred 16 30 0.8 1500 Not Occurred 17 30 0.9 1400 Not Occurred 18 27 1.0 1400 Not Occurred 19 25 1.2 1400 Not Occurred 20 25 1.3 1500 Not Occurred

[Table 1] shows the test results for the occurrence of product defects according to the strip temperature of the horizontal cell inlet.

According to the experimental results of the present inventors, the theoretical phenomenon of the temperature and the plating property in the horizontal cell section from the carousel cell can be described as follows.

When plating is performed in a horizontal cell, the strip temperature flowing into the cell may be regarded as the most advantageous plating condition to maintain room temperature (25 to 30 ° C.) as described in Table 1 above.

The reason is that if the strip temperature is higher than room temperature, wetting decreases because the evaporation of water on the strip surface increases, which increases the surface tension of the strip, and the plating electrolyte does not easily spread on the strip surface due to the increase of the surface tension. This is because the nucleation sites of zinc ions, which are the first steps of plating, are reduced, and thus, a uniform plating layer cannot be secured.

Here, the plating electrolyte does not spread easily means that zinc ions in the electrolyte do not spread evenly on the strip surface.

Therefore, when plating is performed in a state where the strip temperature is higher than room temperature, the corrosion resistance of the formed plating layer is reduced, or visually appears on the plated surface as a stain.

Thus, in the related art, the temperature of the strip flowing into the horizontal cell is controlled by lowering the strip conveying speed. However, this method is not easy to produce a high quality steel sheet because many variations occur according to seasonal factors and operating conditions.

The present invention is to solve the above problems, an object thereof is to provide an electroplating apparatus that can remove the surface defects and produce a plated steel sheet having excellent plating quality, can reduce the power consumption, and improve the productivity It is.

The present invention to achieve the above object,

In the electroplating apparatus comprising a carousel cell having a first plating unit and a second plating unit, and a horizontal cell installed in the rear end of the carousel cell along the strip conveying direction, to produce a pure zinc steel sheet While flashing nickel, an electroplating apparatus using only one electrolytic cell each of a plurality of electrolytic cells provided in the first plating unit and the second plating unit is provided.

The electroplating apparatus of such a configuration can reduce power consumption and suppress surface defects of the strip since the remaining electrolytic baths are not used when producing pure zinc steel sheet.

In addition, the electroplating apparatus according to an embodiment of the present invention to set the temperature of the strip flowing into the horizontal cell by installing a temperature control unit for controlling the temperature of the strip on the strip transfer path between the carousel cell and the horizontal cell By maintaining the temperature within the range it is possible to produce a plated steel sheet of excellent surface quality.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a schematic view showing the configuration of an electroplating apparatus according to an embodiment of the present invention, Figure 2 is a schematic diagram showing the configuration of the main portion of the carousel cell provided in the electroplating apparatus of Figure 1, Figure 3 It is a schematic diagram which shows the structure of the principal part of the horizontal type cell provided in the plating apparatus.

4 is a schematic view showing the configuration of the main part of the first temperature control part provided in the electroplating apparatus of FIG. 1, and FIG. 5 is a schematic view showing the configuration of the main part of the second temperature control part provided in the electroplating apparatus of FIG. 1. .

As shown, the electroplating apparatus according to the embodiment of the present invention includes a carousel cell 10 and a horizontal cell 20.

The carousel cell 10 has a first plating unit 110 and a second plating unit 130 for plating on both sides of the strip S, and the first plating unit 110 transfers the strip. The first to fourth electrolytic cells 112, 114, 116 and 118 along the direction, and the second plating unit 130 includes the fifth to eighth electrolytic cells 132, 134, 136 and 138 along the strip transfer direction.

Each of the first to eighth electrolytic cells is provided with one conductor roll 120 and a pair of support rolls 122, respectively. In this case, the support roll 122 may be adjacent to each other the electrolytic cell.

The carousel cell 10 of such a configuration is used when producing a zinc-nickel steel sheet, and is also used when performing a nickel flash operation to produce a pure zinc steel sheet.

By the way, when performing the above-mentioned nickel flash operation, it is not necessary to use all of the roll sets (refer to one conductor roll and a pair of support rolls) provided in the first to eighth electrolytic baths.

Thus, in the exemplary embodiment of the present invention, the fourth electrolytic cell 118 of the first plating unit 110 and the roll set provided in the electrolytic cell 118 and the eighth electrolytic cell 138 of the second plating unit 130 and the same Nickel flash operation is performed using only the roll set provided in the electrolytic cell 138.

According to this configuration, during the nickel flashing operation to produce the pure zinc steel sheet, two roll sets (the fourth electrolytic cell and the eight electrolyzer roll sets) of the total eight roll sets provided in the carousel cell 10 are used. And the remaining six roll sets (say the roll sets of the first to third electrolytic baths and the fifth to seventh electrolytic baths) can stop driving, thereby reducing the power consumption.

In addition, since the surface defects (foreign matters, roll marks, dent marks, etc.) that can occur while passing through the remaining six roll sets can be suppressed, a steel sheet with reduced surface defects can be produced.

The horizontal cell 20 includes a receiver tank 210, an insulated separator 220, an insoluble anode 230, a conductor roll 240, and a backup roll 250.

On the other hand, the electroplating apparatus according to an embodiment of the present invention is provided with a temperature control unit for maintaining the temperature of the strip (S) flowing into the horizontal cell 20 within a set temperature range (25 ~ 30 ℃).

In general, a dryer is installed at the exit side of the carousel cell 10 to dry the plating film. Therefore, at the exit side of the carousel cell 10, the temperature of the strip S is measured at about 60 to 65 ° C. In order to obtain excellent plating quality, the strip temperature is lowered to a temperature within a set temperature range and then horizontally. It must be introduced into the cell 20.

Thus, the electroplating apparatus according to the embodiment of the present invention between the first temperature control unit 30 and the second temperature control unit 40 between the exit side of the carousel cell 10 and the entrance side of the horizontal cell 20. Equipped.

The first temperature control unit 30 installed adjacent to the exit side of the carousel cell 10 has a spray nozzle 310 for spraying coolant on both sides of the strip S and a surface of the strip S. And a squeeze roll 320 for removing cooling water.

In addition, the first temperature control unit 30 is installed in the front end of the injection nozzle 310 along the conveying direction of the strip (S) first temperature sensor (S1) for detecting the first temperature of the strip (S) And a second temperature sensor S2 installed at the rear end of the spray nozzle 310 along the conveying direction of the strip S to sense a second temperature of the first cooled strip S, and a coolant temperature. At least one of a third temperature sensor S3, a cooler 330 for lowering the temperature of the cooling water according to the signal of the third temperature sensor S3, and first to third temperature sensors S1, S2, and S3. It may include a pressure regulator 340 for receiving a signal from any one of the sensors to adjust the amount of cooling water injection.

In addition, the first temperature controller 30 may further include a filter 350 for filtering the cooling water in order to prevent surface defects from being generated by foreign matter included in the cooling water.

In FIG. 4, reference numerals 360 and 370 are rolls installed to prevent the strips from running out due to the coolant sprayed from the spray nozzle.

In addition, the second temperature control unit 40 installed adjacent to the horizontal cell 20 between the first temperature control unit 30 and the horizontal cell 20 having such a configuration includes a plurality of multistage nozzles ( A tank 420 in which 410 is installed, a fourth temperature sensor S4 for detecting a third temperature of the strip S cooled or cooled while passing through the multi-stage nozzle 410, and the strip S Cooling water supply unit 430 for supplying pure water or heating water to the multi-stage nozzle 410 in accordance with the second temperature and the third temperature of the and the circulation pump 440 for circulating the cooling water collected in the tank 420 It may include.

In FIG. 5, reference numeral 450 denotes a circulation tank, reference numeral 460 denotes a mixing tank in which pure water and heated water are mixed, and reference numeral 470 denotes an automatic valve for controlling the heating water supply.

Hereinafter, a process of producing a pure zinc steel sheet using the electroplating apparatus of the above-described configuration will be described.

First, when producing a zinc-nickel steel sheet, both the carousel cell 10 and the horizontal cell 20 are used. At this time, the first to eighth electrolytic cell of the carousel cell 10 and a total of eight roll sets provided in the electrolytic cell are used.

In addition, when producing a pure zinc steel sheet, a nickel flash operation is performed using the carousel cell 10 described above. In this case, a fourth electrolytic cell provided in the first plating unit 110 of the carousel cell 10 is used. 118 and the roll set provided in this electrolytic cell, the 8th electrolytic cell 138 provided in the 2nd plating unit 130, and the roll set provided in this electrolytic cell are used.

That is, the first to third electrolytic cells 112, 114 and 116 of the first plating unit 110, the roll sets provided in the electrolytic cell, and the fifth to seventh electrolytic cells 132, 134 and 136 provided to the second plating unit 130, and the same. The roll sets provided in the electrolyzer stop running during the nickel flashing operation described above.

When producing a pure zinc steel sheet, the first temperature and the second temperature of the strip S are sensed by the first temperature sensor S1 and the second temperature sensor S2.

Herein, the first temperature of the strip S refers to the strip temperature at the tip of the injection nozzle, and the second temperature refers to the strip temperature after being primarily cooled by the cooling water injected from the injection nozzle 310.

Then, the coolant temperature is sensed by the third temperature sensor S3.

When the first temperature, the second temperature, and the coolant temperature of the strip are sensed as described above, the controller (not shown) determines whether the second temperature exceeds a set temperature range, and operates the cooler 330 to operate the coolant temperature. Spray coolant while lowering

Here, the set temperature range refers to a temperature range set to improve the plating quality, and according to the experimental results of the present inventors, it is 25 to 30 ° C. as shown in the above [Table 1].

In addition, the control unit appropriately adjusts the injection amount of the coolant injected from the injection nozzle 310 by detecting the temperature variation change according to the seasonal change and the strip temperature change according to the strip conveying speed.

Here, the change in temperature deviation of the strip according to the seasonal change may be calculated based on the first temperature detected by the first temperature sensor S1, and the change in temperature according to the strip conveying speed may be calculated by the second temperature sensor S2. It can calculate based on the 2nd temperature detected by.

In addition, the control unit (not shown) of the second temperature controller 40 receives the second temperature signal sensed by the second temperature sensor S2 and selectively selects pure water and heated water in the multistage nozzle 410. Spray through.

At this time, the control unit may adjust the injection amount of the pure water and the heating water based on the third temperature of the strip detected by the fourth temperature sensor (S4), and if it is detected that the third temperature is maintained within the set temperature range One injection can be kept constant.

In addition, the coolant sprayed through the multi-stage nozzle 410 and collected in the tank 420 and the coolant mixed in the mixing tank 460 may be circulated and reused by the circulation pump 440.

Although the present invention has been described in detail through specific embodiments, it is apparent that the present invention is not limited thereto and may be modified or improved by those skilled in the art within the technical spirit of the present invention.

As described above, the electroplating apparatus according to the embodiment of the present invention can reduce power consumption when producing pure zinc steel sheet, and can produce pure zinc steel sheet with reduced surface defects.

In addition, by optimizing the temperature of the strip flowing into the horizontal cell, it is possible to produce a plated steel sheet having excellent plating quality.

Claims (10)

A carousel cell including a first plating unit having a plurality of electrolytic cells and plating one side of the steel plate, and a second plating unit having a plurality of electrolytic cells and plating the other side of the steel plate; And Horizontal cell disposed at the rear end of the carousel cell along the transport path of the steel sheet An electroplating apparatus used to produce zinc-nickel steel sheet and pure zinc steel sheet, The electroplating apparatus using only one electrolytic cell of each of the plurality of electrolytic cells provided in the first plating unit and the second plating unit while flashing nickel to produce the pure zinc. The method of claim 1, The first plating unit is provided with first to fourth electrolytic cell in the conveying direction of the strip, the second plating unit is provided with electrolytic cell of the fifth to eighth along the conveying direction of the strip. The method of claim 2, The electroplating apparatus, wherein only the fourth electrolytic cell of the first plating unit and the eighth electrolytic cell of the second plating unit are used while flashing the nickel. The method according to any one of claims 1 to 3, An electroplating apparatus having a first temperature control unit for lowering the temperature of the strip supplied to the horizontal cell between the exit of the second plating unit and the mouth of the horizontal cell. The method of claim 3, wherein the first temperature control unit, A spray nozzle for spraying coolant on both sides of the strip; A first temperature sensor and a second temperature sensor which are respectively installed at the front end and the rear end of the spray nozzle along the conveying direction of the strip to sense the temperature of the strip; A squeeze roll for removing cooling water from the surface of the strip; A third temperature sensor detecting the coolant temperature; And A cooler for lowering the temperature of the coolant according to the signal of the third temperature sensor Electroplating apparatus comprising a. The method of claim 5, wherein the first temperature control unit, The first temperature sensor and the second temperature sensor are used to sense the first and second temperatures of the strip, the third temperature sensor is used to sense the coolant temperature, and the second temperature exceeds a set temperature range. An electroplating apparatus operable to spray coolant while lowering the coolant temperature by operating the cooler. The method of claim 6, The set temperature range is 25 to 30 ℃ electroplating apparatus. The method of claim 7, wherein An electroplating apparatus, wherein a second temperature controller is installed between the first temperature controller and the mouth of the horizontal cell. The method of claim 8, wherein the second temperature control unit, A tank in which a plurality of multi-stage nozzles are installed; A fourth temperature sensor detecting a third temperature of the cooled or heated strip while passing through the multi-stage nozzle; A cooling water supply unit supplying pure water or heating water to the multi-stage nozzle according to the second and third temperatures of the strip; And Circulation pump for circulating the coolant collected in the tank Electroplating apparatus comprising a. The method of claim 9, wherein the second temperature control unit, When the second temperature exceeds the set temperature range, the strip is cooled while supplying cooling water until the third temperature is within the set temperature range, and when the second temperature is below the set temperature range, the third temperature is set temperature range. An electroplating apparatus for heating a strip while supplying coolant until it is contained therein.

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