JPH08209367A - Iron electrolyzer - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an iron electrolysis apparatus in which electrocoating does not deposit inside the electrolytic cell during operation of the iron electrolysis apparatus, the iron anode can be easily replaced, and the utilization rate of the iron electrode is high. [Structure] An iron electrode installed inside the electrolytic cell 1 is installed so as to be insulated from the main body of the electrolytic cell 1, an anode 6 is electrically connected and fixed to the base, and the iron anode is insulated from the base. It is constructed integrally with the cathode 12 fixed to the outer peripheral portion of the electrode, and due to the structure separated from the internal structural material, the situation of adhesion of the electrocoating to the internal structural material is eliminated, the replacement work is facilitated, and the iron is The electrode surface utilization rate was improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron electrolysis device for preventing the inner surface of a copper alloy cooling pipe such as a heat exchanger from being corroded by seawater.

[0002]

2. Description of the Related Art Generally, corrosive seawater is used as cooling water in heat exchangers used in factories or ships in coastal industrial areas. As a method to prevent corrosion by seawater,
(A) a method of preventing corrosion of the inner surface of a copper alloy cooling pipe by adding ferrous sulfate to cooling water such as seawater and mixing, and (b) providing a bypass in the cooling water channel of seawater and By connecting the electrolyzer, electrolyzing the iron plate for iron ion generation in the seawater supplied into the electrolyzer through the bypass, and using the seawater containing the electrogenerated iron ions as cooling water There is known a method of preventing the inner surface of a copper alloy cooling pipe such as an exchanger from being corroded by seawater.

However, the above-mentioned method of adding ferrous sulfate has a problem in that in addition to manpower required for injection management of chemicals, ferrous sulfate is released into the ocean and pollutes nearby seawater. From the point of view, it is in the direction of self-regulation.
Therefore, a method of producing electrolytic iron ions by using the iron electrolysis apparatus of the above (b) and injecting the electrolytic iron ions to protect the inner surface of the cooling pipe from corrosion is widely used. FIG. 2 shows a longitudinal sectional view of a conventional iron electrolysis apparatus, and FIG. 3 shows a transverse sectional view thereof.

In FIGS. 2 and 3, reference numeral 1 denotes an electrolytic cell body having an inner surface rubber-lined. Inside the electrolytic cell body 1, a pair of insulative synthetic resin plates 19 and 19 'such as FRP having vertical grooves having a U-shaped cross section as an iron electrode holding frame are arranged facing each other at a predetermined interval. It is fixed to the main body 1 via flanges 22 and 23 of insulating structural material. Both ends of the plate-shaped iron electrodes 18a, 18b, ... 18n are fitted and attached to the groove. The iron electrodes 18a, 18b,
18n is a pair of wire connecting members 20 connected in parallel at the upper end,
It is connected to the DC power supply 17 by 20 '.

Bypass pipe 21 and seawater inlet nozzle 13
The seawater flowing into the electrolytic cell body 1 from the iron electrode 18a, 18
18n is discharged to the seawater outlet nozzle 14 and the bypass pipe 21 '. At this time, the iron electrode 18
When an electric current is applied from a, 18b, ... 18n, iron ions (Fe ²⁺ ) are eluted from the surface of the anode part of the iron electrode, seawater containing iron ions is mixed with the cooling seawater, and copper of a heat exchanger or the like is mixed. Corrosion of the inner surface of the alloy cooling pipe is prevented.

When the electric current is passed through the iron electrodes 18a, 18b, ... 18n, the electrolysis of seawater causes CaCO ₃ or Mg (O 2
H) ₂ etc. adheres to the surface of the cathode part and accumulates as the amount of electrolysis increases and narrows the flow path of seawater. Therefore, the polarity of the DC power supply device 17 is reversed at regular intervals to the cathode surface. The deposited electrocoating is forcibly removed.

[0007]

However, the surroundings of the iron electrode are insulating synthetic resin plates 19 and 19 'and the flange 2.
In the portions such as 2 and 23 which are in contact with the insulating structural material inside the electrolytic cell, when the electrocoating is deposited on the cathode surface, a part of the electrocoating also adheres to the insulating structural material. The electrocoating adhered to the insulating structural material cannot be forcibly removed like the electrocoating deposited on the cathode surface.

Therefore, when the iron electrolytic cell is opened, it is necessary to remove a large amount of electrocoating adhered to the insulating structural material, but the insulating synthetic resin plates 19 and 19 'are used.
In addition, the flanges 22 and 23 fixed in the tank must be accessed in the tank, which requires a great deal of labor for cleaning. On the other hand, this iron electrode 18
18n are inserted into the vertical grooves of the insulating synthetic resin plates 19 and 19 'after being mounted on the upper portion of the electrolytic cell as described above, and the iron electrodes are considerably heavy. If the corners collide with the insulating synthetic resin plates 19 and 19 ', the insulating synthetic resin plates may be damaged.

The iron electrode is made of an insulating synthetic resin plate 19,
Since the vertical groove 19 'is used as the supporting portion, the size of the iron electrode, the interval of the insulating synthetic resin plate, and the size of the vertical groove are substantially the same to prevent rattling. Therefore, the work of exchanging the iron electrode must be performed accurately and carefully, which requires a great deal of labor and time. Further, the iron electrodes 18a, 1
Insulating synthetic resin plates 19, 19 'around 8b, ... 18n
Since it is covered with an insulating structure such as, the exposure rate is low, and this portion cannot be used as an iron electrode, resulting in a low utilization rate.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to improve the structure for supporting electrodes in the electrolytic cell,
An object of the present invention is to provide an iron electrolysis device that eliminates the adhesion of electrocoating to the internal structural material of an electrolytic cell, simplifies the work of replacing the iron electrode, and improves the utilization rate of the iron electrode.

[0011]

In order to achieve the above object, in an iron electrolysis apparatus of the present invention, an electrolytic cell body made of metal, an iron electrode installed inside the electrolytic cell body, and the iron electrode are provided. An iron electrolysis device basically composed of a direct current power supply device for supplying a direct current to a base, the iron electrode being insulated from the main body of the electrolytic cell, and fixed to the base by conducting. The iron anode and the cathode which is insulated from the base and fixed to the outer periphery of the iron anode are integrally formed.

The iron electrode is composed of a pedestal whose base is insulated and fixed to the electrolytic cell main body, and a core rod made of an insoluble metal which is erected from the pedestal to the inner surface side of the electrolytic cell main body. It is an iron anode having a central hole that fits into a core rod made of an insoluble metal, and the cathode arranged on the outer peripheral portion of the iron anode may be rod-shaped.

[0013]

With the structure in which the cathode portion does not come into contact with the internal structural material of the electrolytic cell, it is possible to prevent the electrocoating from adhering to the internal structural material of the electrolytic cell even if the electrocoating is deposited on the cathode portion. Cleaning work inside the electrolyzer becomes easy. The pedestal is installed so as to be insulated from the electrolytic cell, the anode part having a central hole that fits into the core rod made of insoluble metal erected on the pedestal is electrically connected and fixed, and the cathode part is insulated from the pedestal. Since it is fixed to the outer peripheral portion of the anode portion to have an integral structure, the work of replacing the iron electrode is easy.

Further, since the periphery of the iron electrode is covered with an insulating synthetic resin plate or the like, the unused portion of the iron electrode surface is reduced.

[0015]

The operation and structure of the iron electrolysis apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of an iron electrolysis device showing one embodiment of the present invention. The main body of the electrolytic cell 1 shown in the figure is made of a steel material whose inner surface is rubber-lined, and a lid 2 made of steel material whose inner surface is also rubber-lined is fixed to the upper portion of the main body by a bolt and a nut. Has been done. Further, the lid 2 is provided with a seat 3 for attaching an iron electrode.

4 is a pedestal having a flange 4a,
The pedestal 4 is fitted in the hole of the seat 3, and is fixed to the seat 3 by being insulated from the seat 3 with bolts and nuts. Reference numeral 5 denotes a core rod made of a noble metal such as titanium, stainless steel, and niobium whose one end is screwed to the pedestal 4 and which is more precious than iron. Reference numeral 6 denotes an iron anode having a center hole fitted and fixed to the core rod 5. In the illustrated example, a plurality of split pieces 6a are stacked in the axial direction and stacked. The pedestal 4 serves as a power supply terminal for the iron anode 6 by passing the current from the DC power supply device 17 through the core rod 5. A cathode mounting plate 7 having a diameter larger than the outer diameter of the iron anode 6 is closely attached to the end surface of the iron anode 6 facing the lid 2. The cathode mounting plate 7 is a lead wire penetrating the pedestal 4 or other means. It is connected to the negative electrode side of the DC power supply device 17.

The cathode mounting plate 7 is made of a mild steel plate for conduction with the lead wire and a cathode 12 which will be described later, and is covered with an insulating coating on the entire surface to insulate the iron electrode 6 and the pedestal 4. On the other hand, on the end surface of the iron anode 6 on the side opposite to the lid 2 side, a current shield plate 8 as a member having a current interruption function by being made larger than the outer diameter of the iron anode 6 itself is closely contacted. . The tip of the core rod 5 is threaded, and the washer 9 and the nut 10 are screwed together to press-fit the above members.

If necessary, a cap 11 is put on the nut 10. Reference numeral 12 denotes a cathode mounted on the outer peripheral portion of a cathode mounting plate 7 arranged around the iron anode 6, one end of which is fixed to the cathode mounting plate 7 and the other end of which is fitted into a hole of the current shield plate 8. It is desirable that a plurality of cathodes 12 are arranged at equal intervals on the concentric circles of the cathode mounting plate 8 in order to make the dissolution of the iron anode 6 uniform.

Reference numeral 13 is a seawater inlet nozzle, and 14 is seawater.
Outlet nozzle, 15 is hydrogen gas or oxygen generated during electrolysis
Degassing to discharge gas and chlorine gas, 16 is drain
It is a pipe. Predetermine the seawater level in the electrolyzer body 1
After maintaining the level, turn on the DC output circuit of the DC power supply device 17.
When activated and a DC voltage is applied to the iron anode 6 and cathode 12,
An electric current flows from the iron anode 6 to the cathode 12 through water, and at the same time,
From the surface of the iron anode 6, iron ions (Fe ²⁺) Elutes.

On the other hand, electrocoating is deposited on the surface of the cathode 12 by electrolysis of seawater. Since the surface area of the cathode of the iron electrolysis apparatus of the present invention is smaller than the surface area of the anode, the cathode current density is large. , If the cathode current density is set to 1 A / dm ³ or more, the growth of electrocoating is suppressed, so the polarity of the anode and cathode is periodically reversed as in conventional iron ion generators where the surface areas of the anode and cathode are almost the same. There is no need to provide a means for doing so.

Further, since the cathode 12 is separated from the inner surface of the electrolytic cell body 1 and the inner surface of the lid 2, the electrocoating deposited on the surface of the cathode 12 is applied to the electrolytic cell body 1 and the lid 2.
Does not adhere to the inner surface and accumulate. To remove the iron anode, the nut 10, the washer 9, and the current shield plate 8 screwed onto the tip of the core rod 4 may be sequentially removed, and then the split piece 6a may be sequentially removed from the top.

Although the figure shows an example in which one set of iron electrodes is attached to the lid 2 of the electrolytic cell, the number of iron electrodes is arbitrary, and the seat 3 and the iron electrode are attached to the electrolytic cell body 1. Good. A specific example will be described. Width 100 cm, length 80 cm, height 9
Five JIS5Kg150A flanges are installed in a 0 cm electrolytic cell, and the pedestal 4, the core rod 5, the iron anode 6, the cathode 12, the cathode mounting plate 7, and the current shield plate 8 shown in FIG. 1 are mounted on these flanges.
And the iron electrode constituted by the nut 10 was attached.

Each iron anode 6 has a diameter of 120 mm and a thickness of 20 mm.
4 pieces of the divided pieces 6a were used. Cathode 1
2 is a steel rod with a diameter of 5 mm, and in order to investigate the relationship between the molten state of the iron anode and the number of cathodes, the number of cathodes of each iron electrode is 6,
Eight, twelve, sixteen, and twenty-four were arranged at equal intervals on the concentric circles on the outer periphery of the iron anode 6.

The positive electrode of the DC power supply device 17 was connected to the pedestal 4 and the negative electrode was connected to the cathode mounting plate 7 to prepare the iron electrolysis device of the present invention. Seawater was supplied to the electrolytic cell so that the flow rate in the electrolytic cell was 0.4 m / sec, and an electric current of about 3 A per iron electrode set was passed for 30 days to examine the presence or absence of deposition of electrocoating. Converting a current of 3 A per set of iron electrodes into a cathode current density, 3 A / dm ² when the number of cathodes is 8, 1.5 A / dm ² when the number of cathodes is 16, 2
In case of four lines, it becomes 1 A / dm ² .

As a result of the test, almost no electrocoating was observed on the inner surface of the electrolytic cell, but the electrocoating was found to have adhered to the root and tip of the cathode 12 5 days after the start of energization. It was observed and grew in a convex shape centering on the cathode 12 with the passage of time. For this reason, when the root portion and the tip portion of the cathode 12 were subjected to an insulation treatment and electricity was continued, no adhesion of electrocoating to this portion was observed.

Further, when the number of the cathodes 12 was 8 or more, the iron anode was dissolved in a substantially uniform disk shape, so it was found that the number of the cathodes is preferably 8 or more.

[0027]

Since the present invention is configured as described above, it has the following effects. (1) Since the iron anode is fitted into a core rod protruding from a pedestal fixed to the electrolytic cell and is easily removable, the work of replacing the iron anode is easy. (2) Since the iron anode is separated from the inner surface of the electrolytic cell, the iron electrode does not collide with the inner surface of the electrolytic cell and damage the rubber lining or the like during the replacement of the anode. (3) Since the electrode is supported and the supporting internal structural material does not need to be protruded in the tank, the electrocoating may adhere and accumulate on the inner surface of the electrolytic cell and the structural material inside the electrolytic cell. Since the surface area of the cathode is small and the surface area of the cathode is small as compared with the surface area of the anode, the electrocoat deposited on the cathode does not deposit. (4) Therefore, the labor for removing the electrocoating adhering to the inside of the electrolytic cell and the cathode is reduced, and the stable operation of the iron electrolysis apparatus can be maintained for a long period of time. (5) If there are eight or more cathodes arranged concentrically around the iron anode at regular intervals, the iron anode will dissolve into a uniform disc shape, so that the unused portion of the iron anode will decrease and Utilization rate improves.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an iron electrolysis device of the present invention.

FIG. 2 is a vertical sectional view of a conventional iron electrolysis device.

FIG. 3 is a cross-sectional view of a conventional iron electrolysis device.

[Explanation of symbols]

 1 Electrolyzer Main Body 2 Lid 3 Seat 4 Pedestal 4a Flange 5 Core Rod 6 Iron Anode 6a Dividing Piece 7 Cathode Mounting Plate 8 Current Shielding Plate 9 Washer 10 Nut 11 Cap 12 Cathode 13 Sea Water Inlet Nozzle 14 Seawater Outlet Nozzle 15 Gas Drain 16 Drain Pipe 17 DC power supply device 18a, 18b, 18n Flat iron electrode 19, 19 'Insulating synthetic resin plate 20, 20' Connection material 21, 21 'Bypass pipe 22 Flange 23 Flange

Claims (2)

[Claims] 1. An iron electrolysis apparatus comprising a metal electrolytic cell body, an iron electrode installed inside the electrolytic cell body, and a DC power supply device for supplying a DC current to the iron electrode.
A base part installed to insulate the iron electrode from the electrolytic cell body, an iron anode electrically connected to the base part and fixed, and a cathode part insulated to the base part and fixed to the outer peripheral part of the iron anode. An iron electrolysis device characterized by being configured. 2. The iron electrode comprises a pedestal whose base is insulated and fixed to the electrolytic cell body, and a core rod made of insoluble metal which is erected from the pedestal to the inner surface side of the electrolytic cell body. 2. The iron electrolysis apparatus according to claim 1, wherein is an iron anode having a central hole that fits into the core rod made of insoluble metal, and the cathode arranged on the outer peripheral portion of the iron anode is rod-shaped. .