JPS5914555B2 - How to supply power to the electrolytic cell - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a method of inserting a grounding electrode into the liquid supply and drainage piping when a large number of electrolytic cells are electrically connected in series and an electrolytic solution is supplied to each electrolytic cell in parallel. , relates to a method for supplying power and liquid to an electrolytic cell, which is characterized by being grounded.

Furthermore, the present invention relates to a power supply and liquid supply method characterized in that a pulp and a pump for supplying and discharging liquid are installed near the ground electrode or apart from the ground electrode when viewed from the rectifier.

Furthermore, insert a grounding electrode into the liquid supply/drainage pipe at half the rectifier voltage and ground it, and install the liquid supply/drainage valve and pump near the grounding electrode or with the grounding electrode separated from the rectifier. A method for supplying power to an electrolytic cell, characterized by
Regarding.

Furthermore, the present invention relates to a method for supplying power to an electrolytic cell, which is characterized by monitoring a current flowing through a ground electrode or a ground potential.

Industrial electrolytic cells generally have an electrolysis voltage of 2 to 1 per tank.
It is 0 volts.

Therefore, by connecting a large number of these electrolytic cells in series and boosting the a terminal voltage to about 100 to 1000 volts, increasing the 25th voltage of the rectifier and lowering the amount of DC current, the price of the rectifier can be reduced as much as possible. Lowering is done. In this case, liquid is normally supplied to each electrolytic cell in parallel. Conventionally, in such cases, the liquid supply and drainage piping was
Rather than actively grounding it, it was insulated from the earth as much as possible, and electrically it was kept floating in the air relative to the earth.

However, in reality, one of the points may touch the ground even slightly for some reason.

As a result, the 15 grounded locations have the same potential as the ground potential, so the pulp, meters, pumps, etc. in the fluid supply and drainage piping become positive or negative relative to the ground, depending on the grounded location. It fluctuates greatly. For this reason, there is a risk of electric shock if you touch valves, pumps, instruments, sampling nozzles, etc. that must be operated during operation. Additionally, metal parts such as pumps and pulp were subject to abnormal corrosion. Furthermore, since no attention has been paid to this point of view in the past, the practice has been to provide 25 pulps for supply and drainage in each electrolytic cell.

Furthermore, not only was it unclear which part was grounded, but it was also impossible to detect when it was grounded and how much grounding current was flowing through it. Therefore, conventionally, the terminal voltage of the rectifier is suppressed to a voltage that is safe even if the charged pulp or pump is touched, or a voltage that is not dangerous even if it is grounded somewhere.

For example, it was common to keep the voltage at about 100 to 250 volts. On the other hand, in the present invention, a 35-ground electrode is inserted into one end of the liquid supply/drainage pipe to ensure that it is grounded.

The principle of the present invention is shown in FIG. In FIG. 1, numeral 1 indicates a group of electrolytic cells electrically connected in series.

2 is a rectifier, 3 is a contact. Ground electrode, 4 is the valve, 5 is the ground ammeter, 6 is the ground, 7 is the pump, R'' is the resistance, 8 is the voltmeter, r is the electrical resistance of the piping that supplies liquid to each battery tank in parallel, R
represents the electrical resistance at the head of the piping that supplies liquid to each tank in parallel.

Places other than the grounding electrode should be insulated from the earth as much as possible.

If this insulation is perfect, the current flowing through the ground electrode to the earth will also be zero. However, in reality, it is grounded from one point to the other, so a closed loop is formed between those ground points and the ground point of the ground electrode, and due to differences in potential between the electrolytic cell 1 and the piping, etc. A circulating current flows through an ammeter 5 connected in series with the grounding electrode. Therefore, if you monitor the readings from the grounding ammeter 5, you will be able to tell if the grounding current has started flowing abnormally due to leakage of liquid from some other part, poor contact insulation of a metal part, etc., and a change in the current value. It can be detected from If the fluctuation value of the grounding ammeter 5 or grounding voltmeter 8 exceeds a certain value, the rectifier power supply can be automatically cut off or a warning can be created by installing a circuit to detect abnormalities in unspecified locations. Major accidents due to grounding can be prevented.

In addition, as shown in Figure 1, close to the ground electrode or away from the ground electrode when viewed from the rectifier, place items such as liquid supply/drain valves, pumps, meters, sampling nozzles, etc. that may cause an electric shock if touched during operation. The risk of electric shock or electrolytic corrosion can be significantly prevented by bringing potentially dangerous metal parts to approximately the same potential as the ground potential.

As shown in Figure 1, when grounding near the positive terminal of the rectifier, the potential difference to ground near the negative terminal of the rectifier in the opposite direction increases, so the danger level when the negative terminal is grounded increases. expensive.

Therefore, as shown in Figure 2, a grounding electrode is inserted into the liquid supply and drainage piping at about half of the rectifier voltage and grounded, and then the liquid supply and distribution valve is connected near the grounding electrode or separated from the grounding electrode when viewed from the rectifier. , a pump, a meter, a sampling nozzle, etc., will not only provide the above-mentioned effects, but also reduce the potential difference between any terminal of the rectifier to the ground by half, thereby reducing the risk in the event of grounding.

Examples of electrolytic cells to which the present invention can be applied include ion exchange K
There are many electrolytic cells for saline solution using the diaphragm method, electrolytic cells for saline solution using the mercury method, water electrolytic cells, electrolytic cells for producing adiponitrile, electrolytic cells for refining copper, nickel, etc.

Further, the type of the battery may be one in which a large number of unipolar electrolytic cells are connected in series, or a bipolar electrolytic cell. Alternatively, an electrodialyzer or the like may be used. Since it is desirable to reduce the leakage current through the parallel liquid supply pipes as much as possible, it is desirable to make the pipes thin and long in order to increase the electrical resistance r of the parallel liquid supply pipes as much as possible.

It is desirable that the grounding electrode in the liquid supply/drainage piping has as large a surface area as possible and has low liquid resistance.

For example, a wire mesh electrode is preferred. The material should be sufficiently corrosion resistant to commercial solution and resistant to electrodes. for example,
Electrodes coated with platinum or platinum metal oxide, graphite, stainless steel, nickel, etc. are preferable. Next, an example carried out to demonstrate the effects of the present invention will be described.

Example 1 In a bipolar electrolytic cell configured by connecting 90 electrolytic cells in series that are divided into an anode chamber and a cathode chamber by a cation exchange membrane, the energized area of each electrolytic cell is 1. 2m x 2.4
It was m.

A 1 m long hose with an internal diameter of 15 mm was connected in parallel from the anolyte tank through the pump, valve, and flow meter, through the ground wire mesh electrode, and through a 6 inch header using a system similar to that shown in Figure 1. The liquid was supplied to the anode chamber of the electrolytic cell.

The anolyte was saline. The anolyte supplied to each anode chamber, together with chlorine gas generated by electrolysis, is also
The liquid was drained from the anode chamber of each electrolytic cell in parallel using a 1 m hose with a length of 1 m, collected in a 6 inch header, passed through a ground wire mesh electrode, and circulated to the valve and then to the anolyte tank. Ru. The grounding wire mesh electrode provided in the anolyte pipe was made by cutting a titanium plate with notches and expanding it to have a porosity of 60%, which was then coated with a solid solution of ruthenium oxide and titanium oxide.

A catholyte circulation system, which is almost the same as the anolyte circulation system described above, was used to supply and drain the cathode chamber of each electrolytic cell in parallel. However, as the grounding wire mesh electrode, a nickel plate with a hole area ratio of 60% was used, which was obtained by cutting and expanding a nickel plate.

Further, the catholyte is caustic soda, and hydrogen gas is generated by resistive electrolysis. A direct current of 360 volts and 13 KA was applied from a rectifier to both ends of such a bipolar electrolytic cell consisting of 90 cells.

At this time, the grounding electrode provided in the anolyte pipe and the grounding electrode provided in the catholyte pipe were both provided on the positive terminal side of the rectifier, as shown in FIG.

The grounding electrode of the anolyte system and the grounding electrode of the catholyte system were connected, and the midpoint of the current meter was connected to the earth through the carbon rod electrode.

As a result, there is a potential difference of about 4V between the anolyte grounding electrode and the catholyte grounding electrode, and a current always flows.
Under normal conditions, the anolyte grounding electrode acts as a positive electrode with respect to the anolyte, and conversely, the catholyte grounding electrode acts as a negative electrode with respect to the catholyte.

However, as a result of insulating the electrolytic cell, headers, valves, piping, meters, pumps, and tanks from the ground as much as possible, the current flowing to the grounded carbon electrode was only about 100 milliamperes under normal conditions.

However, if liquid leaks from the battery container, the reading on the grounded ammeter will fluctuate, so safe operation was possible by installing a circuit that shuts off the rectifier power supply in case of excessive fluctuations in the ammeter. . Example 2 Almost the same as Example 1, but two bipolar electrolytic cells were constructed by connecting 90 cells in series, two of which were electrically connected in series as shown in Figure 2, and the terminal voltage of the rectifier was The difference was 920 volts and carried a current of 13 KA.

In addition, as shown in Figure 2 for both the anolyte and catholyte systems, a grounding electrode was provided in the circulation piping between the two bipolar electrolytic cells.

The grounding electrode and the grounding method are the same as in the first embodiment.

When operating such an electrolytic cell, although the rectifier voltage has doubled, the ground current is approximately 100 mA under normal conditions.
As in Example 1, the vehicle could be operated safely. As explained above, according to the present invention, it is possible to suppress voltage fluctuations in piping due to grounding, and it is possible to operate an electrolytic cell with a high degree of safety.

Furthermore, by monitoring the grounding current, prompt measures can be taken against grounding accidents.

[Brief explanation of drawings]

1 and 2 are piping diagrams showing the principle of the present invention. DESCRIPTION OF SYMBOLS 1... Electrolytic cell group, 2... Rectifier, 3... Grounding electrode, 4... Valve, 5... Grounding ammeter, 6... Grounding, 7... Pump, 8... ...Ammeter.

Claims (1)

[Claims] 1. When connecting a large number of electrolytic cells electrically in series and supplying electrolyte to each electrolytic cell in parallel, insert a grounding electrode into the liquid supply/drainage piping, ground it, and connect the grounding electrode to the ground. 1. A method for supplying power to an electrolytic cell, characterized by connecting an ammeter in series between the two or/and connecting a resistor and a voltmeter in parallel.