JPS5844759B2 - Electrolysis method and device using electrodes with fluid permeation function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolysis method and apparatus using an electrode having a fluid permeation function.

The main points of, for example, anodic oxidation coating treatment of aluminum by a conventional electrolytic method will be explained with reference to FIG.

1' is an electrolytic tank vehicle inspection, 1'-1 is an overflow tank, 2'
is the electrolyte, 3' is the electrode (counter electrode), 4' is the electrode (aluminum to be treated), 5' is the electrolyte absorption piping, 6' is the electrolyte circulation piping, 7' is the electrolysis power supply wiring, 8 ' is an exhaust duct, P' is an electrolyte absorption and circulation pump, B' is an electrolyte filtration device, C' is an electrolyte heat exchange device, R' is an electrolytic power supply device, and D' is an exhaust gas absorption duct. , MB2 is an exhaust cleaning device (
mist separator), and B' is an exhaust blower device.

Both electrodes 3 connected by wiring 7' from electrolytic power supply R'
' and 4'II, an electrolytic current flows through the electrolytic solution 2' in the vehicle model 1', for example, the power supply R'
→ Wiring 7' → Autopsy electrode 4'■ (object to be treated) → Electrolyte 2'+
(c) A circuit of electrode 3'I → wiring 7' → power supply R' is formed, and this causes electrode 4'I, electrolyte 2', and electrolyte 2'
Electrolytic action is performed between the electrode 3'I and the electrode 3'I.

As a result, the electrode 4'■, which is the object to be treated (aluminum), is electrolytically treated and an anodic oxide film is formed on the surface of the aluminum, and the counter electrode 3'I forms an electric path together with the electrolyte 2'. Hydrogen gas is generated from the electrolyte 2'.

Most of the gas generated in this electrolytic treatment step is hydrogen gas, and the presence of a large amount of hydrogen gas in the liquid surrounding the electrode 3'I may obstruct the passage of electrolytic current, and the mixed hydrogen gas When the bubbles rise from the liquid to the upper part of the tank 1' and attempt to disperse into the air, the phenomenon that the mist of the electrolytic solution 2' is brought into the air cannot be ignored.

In this case, in order to collect gas and mist scattered in the air around the tank, an exhaust absorption duct D' is usually provided on the upper side of the tank, and the exhaust duct 8' exhausts the air through the exhaust purifier MS'. It is connected to a blower device B' and discharged into the outside air, and on the other hand, both electrodes 3'I and 4' are connected in the electrolytic tank water tank 1'.
The electrolyte was circulated to maintain the electrolytic conditions in the tank, including around (2).

That is, the electrolytic solution 2' is overflowed from the electrolytic tank water tank 1', and the electrolytic solution 2' received in the overflow tank 1'-1 is
' reaches the electrolyte absorption reflux pump P' through the electrolyte absorption piping 5', and after removing the congested matter in the electrolyte with the electrolyte purging device S', the temperature is controlled with the electrolyte exchanger C'. Then, the electrolyte flows out into the electrolyte reflux pipe 6' and is circulated into the electrolytic tank water tank 1'.

Normal electrolytic treatment conditions are ensured by the combination of liquid management through liquid circulation, control of the electrolytic current from the power supply R', and exhaust gas treatment by the exhaust device, and safe operation is achieved.

However, even if the normal liquid circulation as described above is performed, the electrode 3
'The gas bubbles generated on the surface of I are not easily removed,
The reality is that the bubbles gradually grow and become attached to the surface of the electrode 3'I, or even if they are separated from the electrode surface, they are mixed in a floating state around the electrode surface.

In order to improve this situation, it is possible to increase the flow rate of the electrolyte on the electrode surface and its surroundings by increasing the flow rate of the electrolyte to separate and flush out the gas bubbles. Increasing the number of units will have a large impact on equipment space and funding.

In addition, the current exhaust method (method explained earlier with reference to Figure 1) is to use an exhaust device to collect the generated gas from the tank liquid level into the atmosphere above the tank, where it is about to be dissipated. In order to increase the collection rate, it is necessary to increase the absorption capacity and absorb a large amount of ambient air at the same time, so it is also inevitable that the equipment capacity, space, and funds will increase, so it will not be possible to increase the size and operate efficiently. has many contradictory elements.

The present invention has been devised in view of the above points, and in one electrolytic cell, for example, the object to be treated is used as one electrode, and the same electrode and the other counter electrode are arranged in a pear shape. In an electrolytic device that processes an object by performing an electrolytic action or a precipitation action between the object to be processed and its counter electrode, a material with good conductivity and fluid permeability (porous) is used as the counter electrode. Then, the gas bubbles generated on the wetted surface of the fluid-permeable electrode are permeated together with the electrolyte, most of the generated gas is absorbed in the electrolytic cell, and the electrolyte from which the generated scum has been separated is returned to the electrolytic cell. This relates to the electrolytic method and equipment used.

The present invention will be explained based on the embodiments shown in FIGS. 2 to 4.

2 and 3 are partial longitudinal sectional schematic views of different embodiments, and FIG. 4 is an explanatory diagram of the action of the fluid-permeable electrode (one example) used in the embodiment of FIG. 2. .

1st Embodiment Figure 2 shows an example corresponding to Figure 1, in which 1 is an electrolytic tank, 2 is an electrolytic solution, and 2-1 is a permeable electrolytic solution (the electrolyte/solution also contains generated gas bubbles). 3 is a cylindrical tube-shaped fluid-permeable electrode made of porous material (electrode I), 4 is the object to be treated (electrode), 6 is an electrolyte absorption pipe, 6 is an electrolyte circulation pipe, 7 is an electrolysis power supply wiring , 8 is an exhaust pipe, T is a gas-liquid separation device (airtight tank), P is a pump for electrolyte absorption and reflux, S is a filtration device for electrolyte, C is a deep exchange device for electrolyte, R is a power supply device for electrolysis, B indicates an exhaust blower device, and MS indicates an exhaust gas cleaning device (mist separator).

In the electrolyzer shown in FIG. 2 above, when the aluminum is anodized as shown in FIG. Then, an electrolytic current flows through the electrolyte 2 in the vehicle inspection 1, and the power supply R → wiring 7- + the object 4 of the electrode ■
→ Electrolyte 2 → (@Fluid-permeable electrode 3 of electrode I → Wiring 7 → Power supply R circuit is created, and as a result, the object to be treated 4■, electrolyte 2, electrolyte 2 and fluid-permeable electrode used in the present invention An electrolytic action is carried out between the electrodes 3 and 3I, and at this time, hydrogen gas bubbles are still generated and grown on the liquid contact surface of the electrode 3. Due to its characteristics of good conductivity and porous structure, the surrounding electrolyte 2
permeates into the cylinder, and this flows out into the C pipe 5 due to the suction force of the electrolyte absorption and reflux pump P, thereby absorbing most of the generated gas bubbles into the interior along with the liquid 2, By collecting gas bubbles around the electrodes just before they float, the amount of gas that escapes into the atmosphere from the top of the tank is drastically reduced.

Here, to explain the permeation effect by the fluid permeable electrode 3I with reference to FIG. 4, the electrode 3I is made of a porous material 3A having good conductivity and a hollow cylindrical tube shape, and the electrode lead portion 3-1 An electrolytic current (indicated by the arrow a) is applied from the porous material 3A, and the electrolytic solution 2 is energized in the direction of the arrow on the outer peripheral surface of the porous material 3A to perform an electrolytic action.

On the other hand, the hollow lower end of the porous material 3A forming the electrode 3I is connected to an exhaust blower device B and an electrolyte absorption/recirculation device via a permeate discharge pipe 32, piping 5, and a gas-liquid separator T as shown in the figure. Since it is connected to the inlet of the pump P, the internal pressure inside the porous material 3A becomes negative pressure, and the electrolytic solution 2 permeates from the surface of the porous material 3A toward the hollow portion.

Therefore, the gas bubbles generated on the surface of the porous material 3A pass through the porous electrode material 3A together with the permeated electrolyte 2-1 and are sucked into the hollow portion, and the permeated electrolyte (
Circulating fluid) is moved while being mixed with 2-1.

The permeated electrolyte 2-1 absorbed by gas-liquid mixing passes through the electrolyte absorption pipe 5 and is accommodated in the gas-liquid separator T.

If the capacity of the sealed tank that forms the gas-liquid separator T is sufficiently large compared to the flow rate of the absorbed permeated electrolyte 2-1, the gas-liquid mixture will have gas in the upper part and liquid (electrolyte) in the lower part. liquid)
are separated, and are absorbed from the upper and lower parts into the flow path (the flow path for the exhaust blower B1 electrolyte to the reflux pump P) to proceed to the next stage.

That is, if the electrolytic solution 2 contains sludge or foreign matter, it is removed when it is pushed out by the reflux pump P and passes through the filtration device S, and the electrolytic solution 2 in the vehicle type 1 is further removed in the heat exchange device C. The temperature is controlled to an effective temperature for temperature control, and the water is returned to the water tank 1 via the reflux pipe 6.

The gas absorbed by the blower device B via the exhaust pipe 8 can be removed from mixed mist and impurities by the cleaning device MS and then released into the atmosphere, or can be recovered and used.

In addition, in the above embodiment, the electrolytic solution absorbed in a gas-liquid mixed state from the electrolytic cell is transferred to the suction side (
The mixed gas is separated in a gas-liquid separator T connected to the negative pressure side (negative pressure side) and extracted by an exhaust blower device. It can also be connected and arranged on the discharge side (pressure side).

In this case, the separation of mixed gases proceeds under pressurized air pressure, so a decrease in separation speed and separation rate is observed, but since the separated gas is also in a pressurized state, the absorption effect of the exhaust blower device is reduced. You can omit the gas extraction and use the actual gun.

Second Embodiment This embodiment uses a flat fluid-permeable electrode as shown in Fig. 3, where 11 is an electrolytic tank vehicle inspection, 11-1 is a permeated liquid receiving tank, 12 is an electrolytic solution, and 13 is a fluid permeable electrode. Electrode ■, 1
Reference numeral 4 indicates the object to be treated, which is an electrode (1), 15 is an electrolyte absorption pipe, 16 is an electrolyte circulation pipe, 17 is an electrolytic power supply wiring, 18 is an exhaust pipe, and P, S, C, R, B, and MS are respective numbers. As in Figure 2, a pump for liquid absorption and circulation, a filtration device, a heat exchange device, a power supply device, a blower device, and a cleaning device are shown.

The operation is almost the same as the device of the first embodiment shown in FIG. 2, but the fluid permeable electrode 13I has a flat plate shape, and the electrolytic solution 12 is permeated from the water tank 11 side to the receiving tank 11-1 side, and the permeated liquid is The electrolytic solution 12-1 is separated into gas and liquid in the receiving tank 11-1,
Gas flows from the upper end via piping 18 to exhaust blower device B.
and discharge into the atmosphere through the exhaust cleaning device MS, or
to recover.

In other words, the fluid-permeable electrode of the second embodiment is flat, whereas that of the first embodiment is cylindrical.
Therefore, the only difference is the permeation direction of the electrolyte and gas bubbles and the gas-liquid separation device.

In other words, the part of the gas-liquid separator (airtight tank) T in the first embodiment is replaced with the fluid permeable electrode 13I on the side of the water tank 1.
It has a structure in which flat plate-shaped parts are attached and connected in the form of a partition, and that part serves as a permeated liquid receiving tank 11-1, and is connected via an electrolyte absorption pipe 15 and an exhaust pipe 18, respectively. Due to the action of the liquid absorption reflux pump P1 blower device B, the inside of the permeated liquid receiving tank 11-1 becomes negative pressure, and the water tank 1
An electrolytic solution 12 is sucked in from within the fluid-permeable electrode 1 .
It also absorbs gas bubbles generated on the inspection side surface of 3I.

In the water tank 11, the electrode 1, which is the object to be treated, is passed through the electrolyte 12.
It goes without saying that an electric path is formed between the electrode 411 and the fluid-permeable electrode 13I, and electrolytic action is performed in each case.

Furthermore, although not shown, as another embodiment, fluid-permeable electrodes can be used as both poles in the main tank of the electrolytic cell, and used as an electrolytic device for electrolyzing the electrolytic solution itself.

The material used for the above-mentioned fluid permeable electrode includes, for example, porous carbon with good conductivity, sintered metal, or compact metal, but the function as an electrode is (
1) In the case of polarity or negative polarity, there are inherent difficulties depending on various conditions such as when AC power is applied and chemical resistance depending on the type of electrolyte, so choose the appropriate one depending on each case. should be used.

In short, the present invention provides, for example, in one electrolytic cell, the object to be treated is used as one electrode, and a counter electrode is installed on the other side via an electrolyte, and the two electrodes are formed into a pear shape. In an electrolytic device that performs an electrolytic action or a precipitation action between an electrolytic solution, a workpiece, and its counter electrode to perform a treatment process on the workpiece, the counter electrode has good conductivity and fluid permeability. Most of the generated gas is absorbed in the electrolytic cell by using a material that has a material containing the fluid and allowing gas bubbles generated on the liquid-contacting surface of the fluid-permeable electrode by electrolysis or precipitation to permeate through the fluid-permeable electrode together with the electrolyte. This is an electrolysis method using an electrode having a fluid permeation function, which is characterized in that the generated gas is discharged or recovered into the atmosphere, and the electrolytic solution from which the generated gas is separated is returned to the electrolytic cell.

That is, when using the method of the present invention, (i) a material with good conductivity and fluid permeability is used as the counter electrode of the object to be treated, and the gas generated on the liquid contact surface of the fluid permeable electrode during electrolysis is Since most of the bubbles are absorbed together with the electrolyte, the gas bubbles around the pole can be collected before they become floating, and the amount of gas dissipated into the atmosphere above the tank can be drastically reduced.

In other words, the effect is very efficient because the pollution caused by gas dissipation is absorbed at the source before it is diffused.

([1), Also, the type of gas generated depends on the type of electrode ((+) or (→ pear-shaped)) depending on the type of electrolysis.
If the electrolysis method of the present invention is utilized, it is possible to absorb and collect gas with extremely high purity, so great benefits can be expected when it is desired to recover and utilize gas or when it is desired to process gas.

(iii) Since the floating gas bubbles in the electrolyte are drastically reduced by the above (1), the energization conditions are improved and the electrolytic capacity is increased.

(■) Also, the capacity of the exhaust system is small, the size of the equipment and its space can be reduced, and there are excellent effects such as a significant reduction in funds.

Further, in the present invention, in an electrolytic cell, a material having good conductivity and fluid permeability is used as a counter electrode to the object to be treated, which is one electrode, and the electrolytic solution permeated by the fluid permeable electrode is transferred to the electrolytic cell. a liquid circulation device with a suction pump for returning the liquid; and an exhaust blower for recovering gas bubbles generated on the liquid contact surface of the fluid permeable electrode absorbed with the permeating electrolyte or releasing them into the atmosphere. This is an electrolytic device using electrodes having a fluid permeation function, characterized in that a gas extraction device and a gas extraction device are provided separately.

That is, in the apparatus of the present invention, most of the gas bubbles generated on the liquid contact surface of one electrode, the fluid permeable electrode used as the counter electrode of the object to be treated, are removed by the exhaust blower of the gas extraction device and By operating the electrolyte absorption and reflux pump, the electrolyte passes through the electrode along with the electrolyte from the surface of the counter electrode and is absorbed in the electrolytic cell, and the generated gas is separated and the electrolyte is returned to the electrolytic cell by the liquid circulation device. At the same time, the gas after one of the separations can be released into the atmosphere by a gas extraction device or used for recovery. In addition to being able to reliably carry out the method of the present invention, the following effects can also be achieved. have

In conventional devices, a large amount of gas generated on the liquid contact surface of the counter electrode mixes in the surrounding liquid and obstructs the passage of electrolytic current, and when it dissipates into the air from the liquid, it causes foreign matter such as air or electrolyte mist. The gas recovery rate is poor because the gas is entrained, and the surrounding air is also absorbed, which increases the capacity of the exhaust blower and increases equipment capacity, space, and funding.
According to the device of the present invention, gas bubbles generated on the wetted surface of the fluid-permeable electrode are absorbed together with the electrolyte before they float, so the gas trapping effect can be greatly enhanced, thus eliminating the problems caused by the conventional device described above. do.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view of a part of a conventional electrolysis apparatus, FIGS. FIG. 3 is a cross-sectional view for explaining the structure and operation of the fluid-permeable electrode used in the illustrated embodiment. In the figure, 1, 11... Electrolytic tank water tank, 2, 1
2... Electrolyte, 3, 13... Fluid permeable electrode, 4, 14... Object to be treated, P...
Electrolyte absorption and reflux pump, S...filtration device, C
...Heat exchange device, liquid circulation device with suction pump, B...Exhaust blower 1M5...Cleaning device, gas extraction device with exhaust blower

Claims (1)

[Claims] In the 11 electrolytic cells, for example, the object to be treated is used as one electrode, and a counter electrode is installed on the other side via an electrolyte, and an electric current is applied to the two electrodes. In an electrolytic device that performs a treatment process on a workpiece by performing an electrolytic action or a precipitation action between an electrolytic solution, a workpiece, and its counter electrode, the counter electrode has good conductivity and fluid permeability. Most of the generated gas can be absorbed into the electrolytic cell by using a material having a material having 1. An electrolysis method using an electrode having a fluid permeation function, characterized in that the generated gas is absorbed and released into the atmosphere or recovered, while the electrolytic solution from which the generated gas is separated is returned to an electrolytic cell. 2 In the electrolytic cell, for the object to be treated which is one electrode,
A liquid circulation device with a suction pump for returning the electrolyte permeated by the fluid permeable electrode to the electrolytic cell, with a material having good conductivity and fluid permeability as a counter electrode, and the fluid absorbed together with the permeated electrolyte. It also has a fluid permeation function, characterized in that it is equipped with a separate gas extraction device with an exhaust blower to collect gas bubbles generated on the liquid contact surface of the transmission electrode or release them into the atmosphere. Electrolytic device using electrodes.