JPS5818997B2 - Power supply device for metal strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the invention of a power supply device for a metal strip, which provides a stable voltage to a running metal strip, such as in a continuous electrolytic treatment facility for metal strips, with less voltage loss, and which does not damage the metal strip. The purpose of this paper is to propose a device that can effectively supply a large current without causing any damage.

When electrolytically treating metal strips, continuous electrolytic treatment, in which the desired strips are continuously fed into electrolytic equipment and processed, has the advantage of being highly productive and reducing manufacturing costs. It has been put to practical use in various ways, such as tin plating or galvanizing thin steel sheets, anodizing, electrolytic surface roughening, or electrolytic cleaning treatments on aluminum sheets.

By the way, in order to improve the productivity in such continuous electrolytic treatment, it is necessary to electrolyze the IJ tube at a high current density to achieve the desired electrolytic treatment in a short time.
This is also the reason why high line speed processing can be achieved even with relatively small-scale equipment, but for various purposes, it is an important technical issue to appropriately supply a large current such as 50OA/cIit to the strip. Therefore, the method conventionally used for this purpose is the direct power supply method.
Furthermore, even the indirect power feeding method is not necessarily preferable.

In other words, in the direct power supply method, power is supplied by bringing a conductor connected to the power source into contact with the strip, but the contact between the conductor such as the power supply roll and the running strip is not stable, causing discharge. In other words, an insulating oxide film or corrosion product layer is formed on the surface of the power supply roll, or the strip surface is partially covered with a deposit layer deposited from the solution in the previous process. Contact failure may occur depending on the cause, and even if a strip is wrapped around a power supply roll to supply power over a wide contact area, it is difficult to ensure high contact pressure in that contact area. There are many troubles involved in supplying such a large current.

For this purpose, a power supply roll or a power supply drum is installed in the electrolytic cell,
Electricity is sometimes supplied while being immersed in an electrolytic solution, but in this case, an electrolytic reaction occurs between the roll surface that is not in contact with the strip and the counter electrode, resulting in leakage current, and the roll There are disadvantages such as electrolytic corrosion of the material.

In particular, this electrolytic corrosion is related to the roll material, electrolyte, current waveform, electrolytic conditions, etc., and it is not easy to appropriately select these factors to achieve favorable operation without electrolytic corrosion, and it is difficult to prevent leakage current. This is difficult in practice, and a preferred method for supplying current to the power supply roll even if it collapses has not been established.

The indirect power supply method is also called the liquid power supply method, in which power is supplied to the strip from the counter electrode in the power supply tank through the power supply liquid, and then in the electrolytic tank again through the electrolyte [although electrolytic treatment is performed between it and the J electrode]. In this case, a type of electrolytic treatment is performed in the power supply tank, which generates an electrolytic voltage and causes a large voltage loss.Also, considerable care must be taken with the composition of the power supply solution, and the power supply solution and electrolyte If the composition of the electrolyte is different, the composition of the electrolyte will change during operation, so it is necessary to intervene in a cleaning process between them. There are many technical problems, such as voltage loss due to resistance.

The present invention was devised after repeated studies in view of the above-mentioned circumstances, and the specific embodiment thereof will be explained as shown in the attached drawings.As shown in Fig. 1, the strip 1 is an electrolytic cell. The electrolytic cell 10 is wound from a guide roll 1a provided at an appropriate position in front of the entrance side of the electrolytic cell 100 to a pass roll 2 provided at the upper part of the entrance side of the electrolytic cell 100.
is guided by the immersion roll 6 in the electrolytic cell 10, passes through the lower surface of the support body 10a in the electrolytic cell 10, and is pulled out to the exit side.
A necessary electrolytic treatment is applied while passing through an electrolytic zone 4 filled with an electrolytic solution between the support body 10a and the counter electrode 5 provided below the entry side immersion roll 6. In order to supply power to the strip 1, the above-mentioned pass roll 2 is formed of an insulating hard member such as hard rubber.
A power supply roll 3 made of a member with good electrical conductivity, that is, generally a metal material, is provided above, and a suppression mechanism 7 as shown in FIGS. 2 and 3 is provided for this power supply roll 3. Then, the power supply roll 3 is pressed against the pass roll 2.

A conductive liquid lance 9 is provided on the front side between the pass roll 2 and the power supply roll 3 as described above, and the conductive liquid is discharged and supplied to the portion of the power supply roll 3 to be crimped as described above. Another coolant lance 8 is provided on the rear side between the pass roll 2 and the power supply roll 3, that is, on the side of the electrolytic cell 10, facing the lance 9, so that the strip 1 receiving power can be appropriately cooled. be.

The details of the arrangement and operational relationship of the pressing mechanism 7 with respect to the power supply roll 3 as described above are as shown in FIG.
The shaft portion 2d of the power supply roll 3 is supported by the housing 2c mounted on the frame 2b, i.e., is fixedly supported, whereas the shaft portion 3d of the power supply roll 3 is mounted on the bracket 3c mounted on the frame 2b. A sliding guide 3b that can be slid in the vertical direction is disposed, and the housing 3a is supported by a bearing on the housing 3a, which is attached to the sliding guide 3b. The rods 7a of the pressure mechanism 7 are connected to each other so as to apply the required contact pressure.

As shown in FIG. 2, the guide roll 1a and the dipping roll 6 are supported by bearings attached to the fixed stand 2a.

The mechanism for supplying a large current to the power supply roll 3 as described above is as shown in FIG. A fixed shaft 13 is connected to the fixed shaft 13, and a slip ring 14 is installed with respect to the fixed shaft 13 so as to cover the periphery of the universal joint mechanism 16.
4, a plurality of power supply brushes 15 are disposed to supply power from an external power source to the slip ring 14.
A flexible conducting wire 17 is provided between the coupling 18 provided on the shaft portion 3d to supply power to the power supply roll 3, and the fixed shaft 13 and the universal joint mechanism 16 are connected to the slip ring 14. and insulates the coupling 18.

That is, according to such a power supply mechanism, it is possible to supply a large current to the power supply roll 3, and the flexible joint mechanism 16 and the flexible conductor 17 can be bent as appropriate, so that the power supply roll can be bent in the vertical direction. and strip 1
It is easy to make contact with or break away from the person.

Moreover, the connected power supply with the external power supply is fixed axis 13V? - It is always stable because it is performed on the provided slip ring 14.

A balance weight 20 is appropriately attached to the end of the fixed shaft 13.

To explain the operation of the device according to the present invention as described above, as described above, the strip 1 passing through the pass roll 2 is not supplied with electricity from the pass roll 2, and the pass roll 2 is used as an insulator to further move the strip 1 upward. Although supplying power via another power supply roll 3 appears to have a small contact area with the power supply roll such as strip 1, according to the results of practical studies conducted by the present inventors regarding large current supply, it is very large. For current supply, it is important to apply a large contact pressure, and even if the contact area is small, stable power supply can be achieved by applying a large contact pressure.

Winding the strip 1 as in the case of supplying power between the pass roll 2 and the strip 1 shown in the figure forms an apparently large contact area, but the contact pressure P in this case is From the tension q given to the strip, the roll radius γ and the plate thickness t to obtain a stable running condition, P-q-
The strip tension q is given by t/γ (kg/ff1), and there is a limit to this strip tension q due to the strength of the line equipment and strip material. It becomes only about 2 kg/i.

However, when using the method of the present invention as described above, this contact pressure can be sufficiently increased, and both rolls 2 and 3 are interlocked with gears 11° and 11 so that they have the same circumferential speed as shown in FIG. As a result, even if the strip 1 is operated at a high contact pressure, the strip 1 can be operated without causing problems such as scratches.

Furthermore, when power is supplied to the strip 1 through concentrated contact and a large current is applied in this way, the strip 1 generates considerable heat between its power supply roll 3 and the electrolytic cell 10, and in some cases, distortion occurs in the strip 1. However, such heat generation is cooled by the cooling liquid from the lance 8, and this cooling lance 8 is lowered toward the electrolytic cell 10 from the power supply roll 3 on the electrolytic cell 10 side as shown in FIG. Since the strip surface is supplied to the electrolytic cell 10 in a completely wet state, the first surface of the strip is introduced into the electrolytic cell in a completely wet state and preferably cooled. Cooling, which is advantageous in terms of equipment and operation, can be achieved by supplying a portion of the water to be supplied to the electrolyte storage tank.

The conductive liquid sprayed from the conductive lance 9 assists the conduction at the above-mentioned contact points and prevents the occurrence of sparks, etc. As this conductive liquid cannot avoid being mixed into the electrolytic cell to some extent, it has a negative effect on the electrolytic characteristics. Select a material that does not cause corrosion, wear, or elution of the roll.

In reality, almost all of the current flows through the contact area between the power supply roll 3 and the strip 1, so the current flows from the power supply roll 3 to the strip through the conductive liquid in the vicinity of the contact area, causing the current to flow through the power supply roll 3 and the strip. Select roll materials and conductive liquids that are less likely to cause electrolytic corrosion and prevent oxide films or passive layers from forming on the surface of the power supply port or strip. In most cases, this will not cause any problems.

In this embodiment, in which current is supplied to the power supply roll 3 with the configuration shown in FIG. 3, when the current is not supplied, the power supply roll 3 is moved from the strip 1 by switching the circuit for the cylinder of the pressing mechanism 7 in the opposite direction. It is obvious that it will be disengaged, and in this state the gears it, i'
The engagement between i is also released, so you can inspect the power supply roll and other parts.
This is convenient for maintenance, and of course, by rotating only the pass roll 2 in this state, sheet threading operations can also be carried out advantageously.

To specifically explain an example of operation using the device of the present invention as described above, the thickness is 0.2 to 0.37 fLm and the width is 3
When conveying a 0 omm strip at a line speed of 2 to 20 m/mm and electrolytically treating it in the above-mentioned apparatus, the pass roll 2 has a diameter of 250 m, a length of 400 rt, and a surface length of 400 rt.
tm hard rubber was used, and the power supply roll 3 was made of industrial cotton Atsubenium with a diameter of 200 mm and a surface length of 40077!7M, and the contact between the power supply roll 3 and the strip 1 weighed 2 kg. /ciF, 4500A
As a result of operation with alternating current applied, good contact conditions and power supply were obtained, and the contact voltage between the power supply roll 3 and the IJ knob 1 was stable at an extremely low value of 0.2 V. was confirmed.

A 0.7 to 1% nitric acid solution with the same composition as the electrolyte was used as the cooling liquid and conductive liquid, but the operation was stable for 6 months, and subsequent inspections revealed that the power supply roll and other parts were It was confirmed that no problem-like damage was observed and that good surface quality was maintained, and the amount of current per unit surface length of the power supply roll was 150A/cm, which was still ample, and the voltage loss was small and stable. We were able to continue supplying power.

According to the present invention as explained above, a metal strip is wound around a pass roll provided close to the entrance side of the electrolytic cell and fed into the electrolytic cell, and a power supply roll provided above the pass roll is used to feed the metal strip into the electrolytic cell. By crimping it onto the strip surface and forming a close contact state, it is possible to stably supply a large current to the metal strip without any voltage loss and of course without the occurrence of sparks. Moreover, since a cooling lance is provided on the rear side between the pass roll and the power supply roll to cool the strip receiving power, the heat generated by the strip to which a large current is applied is cooled, causing distortion in the strip. Therefore, it is possible to realize efficient electrolytic treatment in a short time due to high current density, and to carry out advantageous electrolytic work due to high line speed with relatively small-scale equipment, making it suitable for industrial use. This is a highly effective invention.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIG. 1 is a cutaway side view showing the overall structural relationship of an example of continuous electrolytic treatment equipment for metal strips using the power supply device according to the present invention; FIG. 2 is a cutaway side view of the bearing structure in the pass roll and power supply roll portions, and FIG. 3 is a partially cutaway front view showing an example of the power supply relationship to the power supply roll. However, in these drawings, 1 is a metal strip, 2 is a metal strip,
is a pass roll, 3 is a power supply roll, 4 is a %i solution zone, and 5 is a
6 is a counter electrode, 6 is an immersion roll, 7 is a pressurizing mechanism, 8 is a cooling lance, 9 is a conductive liquid lance, and 10 is an electrolytic cell.

Claims (1)

[Claims] 1. A pass roll provided close to the electrolytic cell and above the entrance side thereof is formed in an insulating manner, and a metal strip is wound around the pass roll to form a pass line for passing through the electrolytic zone of the electrolytic cell, and this A power supply roll made of an electrically conductive material is disposed with respect to the pass roll, and a pressure mechanism is provided on the power supply roll so that the power supply roll is brought into linear pressure contact with the above-described wound strip on the circumferential surface of the pass roll. A power supply device for a metal strip, characterized in that a cooling lance for cooling the strip receiving power is provided on the rear side between the power supply roll and the power supply roll.