JPS61253399A - Device for cleaning up plating liquid - Google Patents

Abstract

PURPOSE:To clean a plating liquid and the surfaces of lead electrode plates at all times and to obtain a plated steel sheet having high quality by circulating the plating liquid in a plating cell through a piping system and providing a filter to the piping system. CONSTITUTION:Two sets of liquid flow generating nozzles 7 generate respectively the plating liquid flow between the lead electrode plates 2a and 2b in the direction where the nozzles face the movement of the steel sheet 3. The stripped lead oxides are entrained in the plating liquid flow. The plating liquid strips also the lead oxides on the plates 2a, 2b and is removered into a recovering port 8. The recovered plating liquid is transferred in a piping system 10 by a liquid feed pump 9. The impurities such as lead oxides are removed by the filter 11. The cleaned up plating liquid is again returned by the piping system 10 into the plating cell 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for purifying electroplating liquid for steel plates. More specifically, the present invention relates to a purification device that removes impurities such as lead oxide from a plating solution in a steel plate electroplating tank and keeps the plating solution clean at all times.

A plating apparatus using a conventional lead electrode will be explained with reference to the attached FIGS. 4 and 5.

Figure 4 is a schematic diagram of a vertical plating tank according to the prior art.
The plating apparatus has two pairs of lead electrode plates 2a and 2b arranged vertically in a plating tank 1 facing each other, an energizing roll 4 on the entrance side of the steel plate 3 above the plating tank 1, and a lead electrode plate inside the plating tank 1. It is constructed by arranging a zinc roll 5 below the electrode plates 2a and 2b, and an energizing roll 6 on the exit side of the steel plate 3 above the plating bath 1, respectively. The steel plate 3 enters the plating solution via the current-carrying roll 4, passes between the lead electrodes 2a, passes through the zinc roll 5, passes between the lead electrode plates 2b, exits the plating liquid surface, and passes through the current-carrying roll 6. Transferred to the next process.

The steel plate 3 becomes a cathode by the current-carrying roll 4, and metal ions in the plating solution are electrodeposited by passing between the lead electrodes 2a and 2b, which are anodes, to perform plating.

FIG. 5 is a schematic diagram of a conventional horizontal plating tank, and the plating apparatus includes a pair of opposing lead electrodes 2 in the plating tank,
It is constructed by arranging an energizing roll 4 on the steel plate input side and an energizing roll 6 on the steel plate exit side. The course of the steel plate and the plating mechanism are the same as in the case of using the vertical plating tank shown in FIG. 4.

When using the above plating apparatus, the lead electrode 2 is, for example,
Pb + H20→Pb O+ 2 H” + 2 e
- It is oxidized to form a lead oxide film, but with long-term energization, the lead oxide film gradually becomes thick and scab-like. Then, this lead oxide peels off and gets mixed in between the steel plate 3, the zinc roll 5, and the current-carrying roll 6, creating indentation-like flaws on the surface of the plating layer.

Furthermore, if the scab-like lead oxide film becomes too thick, the plating efficiency and mechanical strength will decrease due to deformation of the surface shape of the electrode, and short circuits will occur due to lead oxide getting stuck between the steel plate and the lead electrode. , the lead electrode had to be replaced.

As described above, lead oxides generated on the lead electrode plate due to the anode phenomenon cause two problems: they deteriorate the quality of the plated steel sheet as a product, and the lead electrode plate has to be replaced sooner.

Problems to be Solved by the Invention The purpose of the present invention is to solve the above-mentioned problems of the prior art, and more specifically, to effectively remove impurities such as lead oxide in the electroplating solution and to eliminate the harmful effects caused by the impurities. The purpose of this invention is to realize a method for electroplating steel sheets that is not available, improve plating efficiency, and provide high-quality plated steel sheets.

Means for Solving the Problems In view of the current state of conventional equipment as described above, the inventors of the present invention have proposed to remove impurities such as lead oxide from the plating solution and to clean the inside of the plating tank to solve the above problems. The present invention was completed based on the discovery that the present invention is extremely advantageous in solving the problem.

That is, according to the present invention, in an apparatus for electroplating by arranging lead electrode plates facing each other in a plating tank and passing a steel plate between the lead electrode plates, the plate is provided on the exit side of the steel plate between the lead electrode plates. a plating solution recovery port provided on the inlet side of the steel plate between the lead electrode plates, one end connected to the plating solution recovery port and the other end terminating in the plating tank, A plating solution purification apparatus is provided, which includes a piping system having a liquid feed pump and a filter for purifying recovered plating solution.

The liquid flow generating nozzle may be provided with its own driving means,
Alternatively, the downstream portion of the filter in the piping system may be connected to the liquid flow generating nozzle so that the liquid flow is generated from the outlet side of the steel plate between the lead electrode plates to the inlet side.

Further, according to a preferred embodiment of the present invention, the plating liquid recovery port and the liquid flow generating nozzle are made of reinforced plastic, and the piping system is a resin piping or a piping whose inner surface is coated with resin.

action Next, the operation of the device of the present invention will be explained.

In an electroplating tank equipped with a purification device according to the present invention, a liquid flow is generated from the outlet side of the steel plate toward the input side by the liquid flow generating nozzle. On the other hand, the lead oxide formed on the surface of the lead electrode plate is easily peeled off by this liquid flow, and the peeled lead oxide is removed by the plating liquid provided on the entrance side of the steel plate between the electrode plates. It is carried to the recovery port and sucked into the plating solution recovery port along with the plating solution. Impurities such as lead oxide are removed from the inhaled plating solution containing lead oxide by a filter in the piping system connected to the plating solution recovery port, and the thus purified plating solution is sent to the plating tank by a solution pump. It will be returned.

Since such cleaning of the plating solution is performed continuously or intermittently during electroplating, impurities such as lead oxide are removed from the plating solution, and impurities formed on the surface of the electrode plate by the liquid flow generating nozzle are removed. The lead oxide layer is peeled off, keeping not only the plating solution but also the electrode plate clean.

EXAMPLES The invention will now be explained by way of examples with reference to the accompanying drawings. Note that these Examples are merely illustrative of the present invention, and do not limit the technical scope of the present invention in any way.

Figure 1 shows a case in which the purification device of the present invention is applied to a vertical plating tank.
An example is shown.

That is, in this vertical plating tank, two sets of lead electrode plates 2a and 2b facing each other are arranged vertically in the plating tank 1, and a current-carrying roll 4 is placed on the steel plate entry side above the plating tank 1, and A zinc roll 5 is placed at the bottom of the lead electrode plates 2a and 2b, an energizing roll 6 is placed on the exit side of the steel plate above the plating bath, and a lead electrode plate 2a,
A liquid flow generating nozzle 7 is provided on the outlet side of the steel plate between the lead electrode plates 2a and 2b, and a plating liquid recovery port 8 is provided on the inlet side of the steel plate between the lead electrode plates 2a and 2b. One end of the plating solution recovery port 8 terminates in the plating tank 1 and is connected to the other end of a piping system 10 having a solution feed pop 9 and a filter 11 in the system. On the other hand, in this example,
The liquid flow generation nozzle 7 is equipped with its own liquid flow generation means.

FIG. 2(a) is a detailed view of one example of the liquid flow generating nozzle 7. The liquid flow nozzle 7 has a flat opening 12 .
discharges the plating liquid fed from the pipe 13 to generate a liquid flow.

FIG. 2(c) is a detailed view of one example of the plating solution recovery port 8. As shown in the figure, the plating solution recovery port has a semi-cylindrical shape and is connected to the piping system 10. The suction port is on the bottom surface in the illustrated example and is not shown. The plating solution is sucked through this suction port and collected into the piping system 10.

To explain the operation of the plating solution purification device shown in FIG.
Each of the sets of liquid flow generating nozzles 7 generates a plating liquid flow between the lead electrode plates 2a and 2b in a direction opposite to the movement of the steel plate 3. The peeled lead oxide is entrained in this plating liquid flow, or the lead oxide on the lead electrode plates 2a, 2b is peeled off by the plating liquid flow and is recovered through the plating liquid recovery port 8. The recovered plating solution is moved through a piping system 10 by a liquid feed pump 9, and impurities such as lead oxides are removed from the plating solution by a filter 11. The plating solution thus purified is returned into the plating tank 1 through the piping system 10.

Therefore, the plating solution in the plating bath 1 is the lead electrode plate 2a.

It is constantly collected and purified between the electrode plates 2b, and even if lead oxide is generated, it is immediately removed from the plating solution or from the surface of the lead electrode plate.

FIG. 3 shows another embodiment of the present invention applied to a horizontal plating tank. This horizontal plating tank has lead electrode plates 2 facing each other in the plating tank, an energizing roll 4 on the inlet side of the steel plate 3 between the lead electrode plates, and an energizing roll on the outlet side of the steel plate 3 between the lead electrode plates. This is a conventional horizontal plating device equipped with 6.

In this plating apparatus, according to the present invention, a steel plate 3 of a lead electrode plate 2 is provided.
A liquid flow generating nozzle 7 is provided on the outlet side of the lead electrode plate 2, and a plating liquid recovery port 8 is provided on the inlet side of the steel plate 3 of the lead electrode plate 2. The plating solution recovery port 8
is connected to the piping system 10.

The piping system 10 is provided with a filter 11 and a liquid feed pump 9, and terminates at the liquid flow generating nozzle 7. Therefore, the liquid flow generating nozzle 7 does not have its own driving means, and the liquid feed pump 9 in the piping system 10 discharges purified plating liquid from its opening to generate a liquid flow. In this way, the liquid flow from the liquid flow generation nozzle 7 is generated by the liquid feed pump 9, and the plating liquid is transferred to the liquid feed pump 9, the liquid flow generation nozzle 7, the plating liquid recovery port 8, the filter 11, and the plating liquid. It is circulated and cleaned like the feed pump 9. As described in detail, the plating solution purifying apparatus of the present invention can constantly clean the plating solution and the surface of the lead electrode plate. Therefore, in the electroplating apparatus equipped with the plating solution purification apparatus of the present invention, high-quality plated steel sheets can be obtained, and the service life of the lead electrode plates can be extended.

[Brief explanation of the drawing]

Fig. 1 shows an example of applying the plating liquid purification device of the present invention to a vertical plating apparatus, Fig. 2(a) is a detailed view of the liquid flow generating nozzle, and Fig. 2(c) is a plating solution purifying device of the present invention. FIG. 3 is a detailed view of the liquid recovery port, and FIG.
As an example, FIGS. 4 and 5 show a conventional plating apparatus having a vertical plating tank and a plating apparatus having a horizontal plating tank, respectively. (main reference number)

Claims (5)

[Claims] (1) In an apparatus for electroplating by arranging lead electrode plates facing each other in a plating tank and passing a steel plate between the lead electrode plates, a liquid flow generator is provided on the outlet side of the steel plate between the lead electrode plates. A nozzle, a plating solution recovery port provided on the steel plate inlet side between the lead electrode plates, one end connected to the plating solution recovery port, and the other end terminated in the plating tank and supplying the solution into the system. A plating solution purification device comprising: a pump and a piping system having a filter for purifying recovered plating solution. (2) The plating liquid purifying device according to claim 1, wherein the liquid flow generating nozzle is provided with its own driving means. (3) The plating liquid purification device according to claim 1, wherein the liquid discharge portion of the piping system is connected to the liquid flow generating nozzle. (4) The plating solution purification device according to any one of claims 1 to 3, wherein the plating solution recovery port and the solution flow generating nozzle are made of reinforced plastic. (5) Claim 1, wherein the piping system is a resin piping or a piping whose inner surface is coated with resin.
The plating solution purification device according to any one of items 1 to 4.