KR200223148Y1 - Apparatus for cleaning phosphate solution in the phosphate coating equipment - Google Patents

Abstract

The present invention provides a device for purifying a phosphate suitable for an electroplating aftertreatment facility for forming a phosphate coating on the surface of the strip while passing the plated strip from the phosphate circulation tank to the phosphate treatment tank supplied with phosphate. Corresponds to an ion analyzer for measuring the concentration of ions dissolved in the supplied phosphate solution, a colorimeter for measuring the whiteness of the strip surface passing through the phosphate treatment tank, and a whiteness of the strip surface measured by the colorimeter. It is characterized by comprising a controller for controlling the discharge timing of the phosphate in the phosphate treatment tank by comparing the difference between the ion concentration in the phosphate solution and the measured ion concentration, it is possible to maintain a uniform surface quality of the strip and Waste can be prevented.

Description

Phosphate cleaning equipment for phosphate coating equipment {Apparatus for cleaning phosphate solution in the phosphate coating equipment}

The present invention relates to a device for cleaning phosphate in a post-treatment facility for forming a phosphate film on the surface of an electroplated strip, and more particularly in a phosphate solution over time in the post-treatment of an electroplated steel sheet. It is possible to solve the problem of inadequate solution exhaustion caused by the irregularity of the surface color of the product due to the nonuniformity of the proper acid ratio (TA / FA) and the increase of the concentration of impurity ions (Zn ⁺² , Fe ⁺² ) In addition, the present invention relates to a phosphate purifier for phosphate coating equipment capable of recycling the discharged solution.

In general, a phosphate coating facility is a facility for coating phosphate on the surface of an electroplated steel sheet upon demand, and includes a phosphate circulation tank in which a phosphate treatment solution is stored, and a phosphate treatment solution is supplied from the circulation tank. The plated steel sheet has a phosphate treatment tank which is coated as it passes.

In other words, in the phosphate coating facility, the film is pumped from the phosphate circulation tank in which the phosphate treatment solution is stored and supplied to the phosphate treatment tank, and the phosphoric acid particles containing Zn (H ₂ PO ₄ ) as the main component in the solution are By chemical reaction with the surface of the plated steel sheet, a phosphate film is attached to the surface of the galvanized strip.

When the phosphate coating operation is performed for a long time, zinc on the surface of the strip is eluted to increase the Zn ⁺² ion concentration in the phosphate solution and also to decrease the hydrogen (H ⁺ ) ion concentration, thereby freely forming the phosphoric acid film. H ₃ PO ₄ ) leads to an acid ratio (TA / FA in phosphate solution) imbalance due to lower free acid (FA). That is, the proper acid ratio (TA / FA) is 6-7, but when the acid ratio is large, the phosphate crystal is coarsened and the amount of adhesion increases, resulting in dark strip surface color. Small acid ratios lead to the refinement of phosphate crystals and a reduction in their adhesion.

For example, the impurity management standard in a phosphate solution is made into Zn ^{+ 2} : 4000 ppm or less, Fe ^{+ 2} : 500 ppm or less. However, elution of Fe ⁺² ions in the strip welds and zinc powder remaining on the strip surface and edges are the main causes of contamination of the phosphate solution. Due to these causes, contamination of various roll surfaces in the phosphate treatment tank causes roll mark defects and whiteness degradation on the strip surface.

Therefore, if the worker arbitrarily judges that there is a sign that a slight defect occurs in the strip product, a part of the phosphate solution is discarded and a fresh supplement solution is added to dilute the degree of contamination of the phosphate solution.

However, this working method causes the following problems.

First, since the degree of contamination of the phosphate solution can not be checked from time to time, it is not possible to respond quickly to changes in the solution composition that changes frequently because the Zn ⁺² , Fe ⁺² , FA, and TA values are controlled in the solution analyzed at predetermined intervals. Do not.

Second, since the color of the strip surface is sensitively affected by the solution contamination, the surface quality of the surface (whiteness, color difference) is checked online using a colorimeter in the product inspection room. There is no clear relationship between when and when a part of the contaminated solution has to be discharged and replenished with a new solution, which leads to variations in strip quality by managing the solution between workers.

Third, the cycle of discharging the solution by solution contamination in the usual phosphate coating operation is made by simple operation experience, resulting in waste of the phosphate solution.

The present invention was devised to solve the conventional problems as described above, and check the contamination of the phosphate solution and the surface color, which is a quality influencing factor of the product online, according to the time lapse of the phosphate coating operation. The purpose of the present invention is to provide a phosphate purifier for phosphate coating equipment that not only maintains the quality of the strip surface uniformly by discharging the working solution and recycles the discharged solution, but also prevents waste of the phosphate solution. have.

1 is a block diagram showing a state in which the phosphate purifier is installed in the phosphate coating equipment according to the present invention.

Figure 2 is a flow chart showing the process of determining the discharge timing of the phosphate solution in accordance with the present invention.

3 is a flow chart showing a solution reprocessing process of the phosphate solution discharged according to the present invention.

<Description of the reference numerals for the main parts of the drawings>

1: phosphate circulation tank

2: phosphate chemical storage tank

3: settling tank

4: temporary storage tank

5: filter

6: phosphate treatment tank

7: ion analyzer

8: color difference meter

In order to achieve the above object, according to the present invention, a phosphate suitable for electroplating after-treatment equipment for forming a phosphate coating on the surface of the strip while passing the plated strip to the phosphate treatment tank supplied with phosphate from the phosphate circulation tank The apparatus for purifying includes an ion analyzer for measuring the concentration of ions dissolved in the phosphate solution supplied to the phosphate treatment tank, a color difference meter for measuring the whiteness of the surface of the strip passing through the phosphate treatment tank, and a color difference meter. And a controller for controlling the discharge timing of the phosphate in the phosphate treatment tank by comparing the difference between the ion concentration in the phosphate solution and the measured ion concentration corresponding to the whiteness of the strip surface.

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

First, as shown in FIG. 1, the phosphate coating facility has a phosphate circulation tank 1 and a phosphate treatment tank 6 through which a phosphate treatment solution is supplied from the circulation tank 1 and an electroplating strip passes.

The device for cleaning phosphate in the phosphate coating equipment is an ion analyzer (7) for collecting the phosphate treatment solution supplied from the phosphate circulation tank (1) to the phosphate treatment tank (6) and analyzing the concentration of ions contained in the treatment solution (7). And a color difference meter 8 provided at the exit side of the phosphate treatment tank 6 to inspect the color of the strip surface.

Therefore, in the phosphate coating process, which is a post-treatment of electroplated steel sheets, the degree of contamination of the treated solution and the color of the strip surface over time are measured using an on-line measuring instrument, and data of correlated factors are collected in an automatic control system. Then, the data of these factors constitutes a program that allows the solution to be discharged under the appropriate conditions for the degree of contamination of the solution and whether the color of the strip surface changes, and the solution automatically discharged by the program is recycled.

Permanently, the pumped solution in the circulation tank (1) containing the phosphate solution is supplied to the ion analyzer (7), the ion analyzer 7 in the phosphate solution FA, TA, The concentrations of Zn ⁺² and Fe ⁺² ions are analyzed and transmitted to the controller 9 which is a solution control system. In addition, the whiteness of the strip is checked by a color difference meter 8 which checks the strip surface quality color, which is a quality determining element of the strip, and data on this is also sent to the controller 9.

Using the data elements received from the ion analyzer 7 and the colorimeter 8, a program is first started to determine the solution discharge timing.

First, referring to FIG. 2, in order to secure the conditions for the system to determine the solution discharge, the operator visually checks the color of the strip surface and samples the discharge solution at the time of discharging the solution by experience. The solution discharge condition is established by combining the data with the data measured by the colorimeter of the product in that state.

That is, reading the whiteness data of the product that has the greatest influence on the timing of the phosphate solution discharge, if the measured value is, for example, '78' or less, signal to open the valve for a predetermined time period to discharge a portion of the circulating solution. Send. And if the measured value of whiteness is 78 or more, the valve 14 is closed.

And it reads in Zn ^{+ 2} ion concentration in a phosphate solution, and transmits it as a signal to open the valve 14, when Zn ^{+ 2} concentration is more than 4000 ppm which is a set value. Otherwise, read the TA and FA values in the phosphate solution to calculate the acid ratio (AR; TA / FA) and send a signal to open the valve 14 when the acid ratio measurement is above the set value of '7'. do. Otherwise valve 14 remains closed.

In the stepwise condition check, when the valve 14 is opened, it calculates the discharge amount (1.5 ~ 2㎥ / 1 time: the setting is 2㎥) by analyzing the results of the normal operation, as much as the set value when opening the valve 14 The opening timing is sent by calculating the opening timing of the valve 14 to be discharged. During the time that the open signal is sent out, the valve 14 is opened and the contaminated discharge solution is transferred to the settling tank 3.

At the end of the transfer of the solution by the set amount, the valve 14 is closed, and the phosphate chemical and the pure water stored in the phosphate chemical storage tank 2 are mixed and replenished to the circulation tank 1 to replenish the new solution by the discharge amount. The automatic control process of the work is currently controlled by the solution management system), diluting the contamination of the solution to fall within the solution concentration management range, thereby keeping the working solution clean.

After this, when the next data is received, it is repeatedly performed in the same manner.

On the other hand, if the phosphate solution contaminated beyond the storage capacity of the settling tank 3 is stored, the excess is no longer stored in the settling tank 3 and is discharged to the pit 16 through the valve 15.

Therefore, the phosphate purifier according to the present invention is to temporarily store the discharged solution to secure the free storage space of the full settling tank (3) in order to recycle the discharged solution to remove the waste element of the phosphate solution It has a temporary storage tank (4) for the filter and a filter (5) for removing impurities from the discharged solution. On the other hand, automatic valves 11, 12, 13 are provided as an auxiliary device for automatically controlling the flow of the phosphate solution between the precipitation tank 3, the temporary storage tank 4, and the filter 5.

For example, the sedimentation tank (3) storage level is maintained at a level (15㎥) that can always accommodate the capacity (≒ 6㎥) discharged three times from the maximum capacity 20㎥, and temporarily stored about 3㎥ It is stored in the tank 4 (volume 5m 3) and precipitated for an appropriate time (for example, 4 hours at room temperature). The precipitated solution is passed through the filter 5 so that impurities are removed and only the clean solution is transferred to the circulation tank 1. By removing the need for new replenishment.

In addition, the filter 5 is provided with a filter cloth for removing the residue of the solution on the conveyor-shaped net in the tank that can receive the solution, and a motor for slowly moving the filter cloth while the solution is introduced.

Referring to FIG. 3, first, the data of the solution level gauge 9 of the settling tank 3 is read, and the solution level is' 2m 3 '(based on one discharge) and the level meter 10 of the temporary storage tank is' 2m 3. Below, the valve 11 is opened to transfer the contaminated phosphate solution to the temporary storage tank 4. The solution transferred to the temporary storage tank 4 is stored in the temporary storage tank for at least 4 hours to deposit impurities.

At this time, in order to increase the deposition effect of impurities, a cooling water supply line is installed inside the temporary storage tank (4). On the other hand, the immersion time setting basis is based on the working experience, and the cycle of one discharge was analyzed as about 2 hours and the deposition effect at a low temperature because the temperature of the working solution, for example, when transferred to a temporary storage tank at 80 ° C. Since it is good to have more than 4 hours to have a sufficient deposition effect, the experimental results were derived.

The solution transferred to the temporary storage tank is about 4 hours after the timer is 'on' so that the valve 13 is opened to filter the impurities in the deposited solution so that the solution is discharged to the top of the filter 5 and at the same time Drive the motor to move the filter cloth. When the solution of the temporary storage tank is completely discharged, the valve 13 is closed and at the same time the driving of the motor is terminated.

Through this process, the deposited solution passes through the filter filter cloth, impurity is trapped, and the clean solution is replenished into the circulation tank (1) to be recycled.

Mutual signal transmission and reception between the ion analyzer for automatic control and the additionally installed automatic valve and controller used a communication method called RS-232C and spare I / O among I / F.

Therefore, according to the present invention, in order to ensure the quality of the surface of the strip during phosphate treatment, the worker has to visually check the surface of the strip by hand, and if the quality is poor, instead of working with experience, it is correlated with the contamination of the solution. When the solution is automatically discharged by setting the correlation data between the surface of the product and the contamination of the solution by receiving the whiteness data, which is an indicator of the surface quality of the product, through the colorimeter and the ion analyzer, which shows the contamination of the solution. It is possible to ensure the uniform surface quality of the strip by determining the and also to reduce the cost by recycling the discharged solution.

The foregoing is merely illustrative of the preferred embodiments of the present invention, and those skilled in the art to which the present invention pertains may make modifications and changes to the present invention without departing from the spirit and gist of the present invention as set forth in the appended claims. It should be recognized.

Claims (3)

A phosphate purifier suitable for an electroplating aftertreatment facility for passing a plated strip through a phosphate treatment tank supplied with phosphate from a phosphate circulation tank to form a phosphate coating on the surface of the strip, An ion analyzer for measuring the concentration of ions dissolved in the phosphate solution supplied to the phosphate treatment tank; A color difference meter for measuring the whiteness of the strip surface passing through the phosphate treatment tank; A phosphate coating comprising a controller for controlling the discharge timing of the phosphate in the phosphate treatment tank by comparing the difference between the ion concentration in the phosphate solution corresponding to the whiteness of the strip surface measured by the color difference meter and the measured ion concentration. Phosphate purifier for equipment. The method of claim 1, And a temporary storage tank for temporarily storing the phosphate solution discharged from the phosphate treatment tank by the controller, and a filter for removing impurities from the phosphate solution stored in the temporary storage tank. Phosphate Purifier. The method of claim 2, The temporary storage tank is phosphate cleaning device for phosphate coating equipment, characterized in that the cooling water flow line is installed.