JP2010215932A - Gas generation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas generation apparatus capable of controlling the liquid level of an electrolyte bath in an electrolytic cell stably to a fixed range with simple constitution. <P>SOLUTION: It is detected by pressure meters 25, 26 whether the pressure in a cathode chamber 3 and the pressure in an anode chamber 4 are equal to or above atmospheric pressure or one of them is lower than atmospheric pressure. It is detected by a first liquid level detecting device 50A whether the liquid level in the cathode chamber 4 shows H or L and it is detected by a second liquid level detecting device 50B whether the liquid level in the anode chamber 4 shows H or L. Opening and closing of an automatic valve 11 of a gaseous hydrogen discharge pipe 7, an automatic valve 15 of a fluorine gas discharge pipe 8 and an automatic valve 21 of a HF supply pipe 20 are controlled based on the detected results of the pressure meters 25, 26, the first liquid level detecting device 50A and the second liquid level detecting device 50B. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas generator that generates gas by electrolysis.

Conventionally, fluorine gas has been used in various applications such as material cleaning and surface modification in semiconductor manufacturing processes and the like. In that case, although fluorine gas itself may be used, various kinds of gases such as NF ₃ (nitrogen trifluoride) gas, NeF (neon fluoride) gas, and ArF (argon fluoride) gas synthesized based on the fluorine gas may be used. Fluorine-based gas may be used.

  In such a field, in order to supply fluorine gas stably, for example, a fluorine gas generator that electrolyzes HF (hydrogen fluoride) to generate fluorine gas is used.

  The fluorine gas generator shown in Patent Document 1 includes an electrolytic cell. The electrolytic cell is partitioned into a cathode chamber and an anode chamber by partition walls. An electrolytic bath made of a KF-HF mixed molten salt is formed in the electrolytic cell. A cathode is provided in the cathode chamber, and an anode is provided in the anode chamber. HF is supplied to the electrolytic bath in the electrolytic cell through the HF supply line, and electrolysis of HF is performed. Thereby, hydrogen gas is generated from the cathode of the electrolytic cell, and fluorine gas is generated from the anode.

  In the upper part of the cathode chamber, an outlet for hydrogen gas is provided. Hydrogen gas generated in the cathode chamber is discharged from the outlet through a hydrogen gas line on the cathode side. An automatic valve and an HF adsorption tower are inserted in the hydrogen gas line. Further, the purge gas is supplied to the cathode chamber through a purge gas line.

  A fluorine gas outlet is provided in the upper part of the anode chamber. The fluorine gas generated in the anode chamber is discharged from the outlet through the fluorine gas line. An HF adsorption tower and an automatic valve are inserted in the fluorine gas line. A purge gas is supplied to the anode chamber through a purge gas line.

  The cathode chamber is provided with first liquid level detection means for detecting the liquid level of the electrolytic bath, and the anode chamber is provided with second liquid level detection means for detecting the liquid level of the electrolytic bath. It has been. The cathode chamber is provided with a pressure gauge for measuring the pressure in the cathode chamber, and the anode chamber is provided with a pressure gauge for measuring the pressure in the anode chamber.

JP 2004-52105 A

  In the above-described fluorine gas generator, when electrolysis (electrolysis) is performed normally, the inside of the electrolytic cell is maintained near atmospheric pressure, and the liquid level in the cathode chamber and the liquid in the anode chamber are maintained. The surface height is almost the same.

  During electrolysis, when the anode chamber becomes pressurized due to the generation of fluorine gas, the pressure in the anode chamber is controlled to be close to atmospheric pressure by, for example, exhausting the anode chamber by a decompressor or opening / closing an automatic valve. The When the cathode chamber becomes pressurized due to, for example, the generation of hydrogen gas and the introduction of nitrogen gas, the pressure in the cathode chamber is increased so that the pressure in the cathode chamber follows the pressure in the anode chamber by a combination of a decompressor such as an ejector and an automatic valve. Adjusted to near atmospheric pressure.

  Thus, in the conventional fluorine gas generator, the pressure in the anode chamber and the pressure in the cathode chamber are measured finely so that the pressure in the electrolytic cell is maintained near atmospheric pressure, and the pressure in the anode chamber and the pressure in the cathode chamber are measured. The liquid level in the anode chamber and the liquid level in the cathode chamber were adjusted by maintaining the pressure at the same level.

  However, in order to perform pressure-following control as described above, it is necessary to provide a high-performance and expensive pressure sensor capable of measuring pressure with high accuracy, and to perform fine pressure control. A complicated pressure regulation system was also required.

  In addition, for example, when the electrolytic cell is small, the allowable range in which the liquid level can be controlled is small, and the smaller the electrolytic cell, the more complicated the pressure adjustment system necessary for pressure control. There is a tendency.

  An object of the present invention is to provide a gas generator capable of stably controlling the liquid level of an electrolytic bath in an electrolytic cell within a certain range with a simple configuration.

  (1) A gas generator according to the present invention is a gas generator that generates a first gas and a second gas by electrolysis, and is a compound that is partitioned into a first chamber and a second chamber and is electrolyzed. An electrolytic bath containing an electrolytic bath containing, a first discharge path for discharging the first gas generated in the first chamber, and a second discharge for discharging the second gas generated in the second chamber A first opening / closing means for opening / closing the first discharge path, a second opening / closing means for opening / closing the second discharge path, a first pressure detecting means for detecting the pressure in the first chamber, The second pressure detecting means for detecting the pressure in the two chambers, and the height of the first liquid level, which is the liquid level in the first chamber, with the first allowable range above the reference liquid level and the lower first First liquid level detecting means for detecting which of the two allowable ranges, and a second liquid which is the liquid level in the second chamber Second liquid level detecting means for detecting whether the height of the liquid is in the first allowable range or the second allowable range, the first liquid level detecting means, the second liquid level detecting means, and the first Control means for controlling the first and second opening / closing means based on the detection results of the pressure detection means and the second pressure detection means.

  In the gas generator according to the present invention, the compound in the electrolytic bath accommodated in the electrolytic cell is electrolyzed, the first gas is generated in the first chamber, and the second gas is generated in the second chamber. . The first gas generated in the first chamber is discharged through the first discharge path, and the second gas generated in the second chamber is discharged through the second discharge path. The first and second opening / closing means are controlled by the control means based on the detection results of the first liquid level detecting means, the second liquid level detecting means, and the first pressure detecting means and the second pressure detecting means. Thus, the first discharge path and the second discharge path are opened and closed. Thereby, the height of the first liquid level that is the liquid level in the first chamber of the electrolytic cell and the height of the second liquid level that is the liquid level in the second chamber are controlled.

  Therefore, the liquid level of the electrolytic bath in the electrolytic cell can be stably controlled within a certain range with a simple configuration.

  (2) The control means is such that the pressure detected by the first pressure detecting means and the pressure detected by the second pressure detecting means are equal to or higher than a set pressure, and the first liquid level detecting means When the height is detected to be in the first allowable range and the second liquid level detecting means detects that the height of the second liquid level is in the second allowable range, the first opening / closing The first and second opening and closing means are controlled so that the means closes the first discharge path and the second opening and closing means opens the second discharge path, and the pressure detected by the first pressure detecting means and The pressure detected by the second pressure detecting means is equal to or higher than the set pressure, the first liquid level detecting means detects that the height of the first liquid level is in the second allowable range, and the second liquid When it is detected by the surface detection means that the height of the second liquid surface is in the first allowable range, the first Closing means opens the first exhaust path, a second opening and closing means to close the second exhaust path, it may control the first and second switching means.

  In this case, since the first and second pressure detection means are used to detect whether or not the pressures in the first chamber and the second chamber are approximately equal to or higher than the set pressure, the first and second pressure detection means are used. There is no need to provide a high-performance and expensive pressure gauge as a means.

  When the pressure in the first chamber and the pressure in the second chamber are equal to or higher than the set pressure, the height of the first liquid level is in the first allowable range, and the height of the second liquid level is in the second allowable range The first opening / closing means closes the first discharge path, and the second opening / closing means opens the second discharge path.

  As a result, the first gas generated in the first chamber is retained in the first chamber, and the second gas generated in the second chamber is discharged through the second discharge path. The pressure difference with the second chamber is reduced, the first liquid level is lowered, and the second liquid level is raised. As a result, the first liquid level and the second liquid level can be brought close to the reference liquid level.

  When the pressure in the first chamber and the pressure in the second chamber are equal to or higher than the set pressure, the height of the first liquid level is in the second allowable range, and the height of the second liquid level is in the first allowable range The first opening / closing means opens the first discharge path, and the second opening / closing means closes the second discharge path.

  Thereby, the second gas generated in the second chamber is retained in the second chamber, and the first gas generated in the first chamber is discharged through the first discharge path, thereby The pressure difference with the second chamber is reduced, the second liquid level is lowered, and the first liquid level is raised. Further, the pressure in the first chamber and the pressure in the second chamber are reduced. As a result, the first liquid level and the second liquid level can be brought close to the reference liquid level height, and the pressure in the electrolytic cell can be brought close to the set pressure.

  (3) The volume of the first chamber is larger than the volume of the second chamber, and the control means is configured such that at least one of the pressures detected by the first and second pressure detection means is lower than the set pressure, The surface detecting means detects that the first liquid level is in the second allowable range and the second liquid level detecting means detects that the second liquid level is in the first allowable range. In this case, the first and second opening / closing means may be controlled such that the first opening / closing means closes the first discharge path and the second opening / closing means closes the second discharge path.

  In this case, since the first and second pressure detection means are used to detect whether or not the pressures in the first chamber and the second chamber are approximately lower than the set pressure, the first and second pressure detection means There is no need to provide a high-performance and expensive pressure gauge as a means.

  At least one of the pressure in the first chamber and the pressure in the second chamber is lower than the set pressure, the height of the first liquid level is in the second allowable range, and the height of the second liquid level is in the first allowable range. In this case, both the first and second discharge paths are closed by the first and second opening / closing means.

  Thereby, the pressure in the first chamber and the second chamber is increased by the first gas and the second gas generated in the first chamber and the second chamber, respectively. In this case, since the volume of the second chamber is smaller than the volume of the first chamber, the pressure difference between the pressure in the second chamber and the pressure in the first chamber is reduced. Thereby, the 2nd liquid level falls gradually and the 1st liquid level rises gradually.

  Therefore, the pressure difference between the first chamber and the second chamber can be gradually reduced to bring the first liquid surface and the second liquid surface close to the reference liquid surface height, and the pressure in the electrolytic cell is set to the set pressure. Can be approached. In this way, it is possible to prevent the pressure difference between the first chamber and the second chamber in the electrolytic cell from proceeding in an expanding direction, and to stably control the pressure and liquid level in the electrolytic cell within a certain range. can do.

  (4) The volume of the first chamber is larger than the volume of the second chamber, and the control means is configured such that at least one of the pressures detected by the first and second pressure detection means is lower than the set pressure, The detecting means detects that the height of the first liquid level is within the first allowable range, and the second liquid level detecting means detects that the height of the second liquid level is within the second allowable range. In this case, the first and second opening / closing means may be controlled such that the first opening / closing means closes the first discharge path and the second opening / closing means opens the second discharge path.

  In this case, since the first and second pressure detection means are used to detect whether or not the pressures in the first chamber and the second chamber are approximately lower than the set pressure, the first and second pressure detection means There is no need to provide a high-performance and expensive pressure gauge as a means.

  At least one of the pressure in the first chamber and the pressure in the second chamber is lower than the set pressure, the height of the first liquid level is in the first allowable range, and the height of the second liquid level is in the second allowable range. The first discharge path is closed by the first opening / closing means, and the second discharge path is opened by the second opening / closing means.

  As a result, the first gas generated in the first chamber is retained in the first chamber, and the second gas generated in the second chamber is discharged through the second discharge path. The pressure difference with the second chamber is reduced, the first liquid level is lowered, and the second liquid level is raised. Accordingly, the first liquid level and the second liquid level can be brought close to the reference liquid level height, and the pressure in the electrolytic cell can be brought close to the set pressure.

  (5) The volume of the first chamber is larger than the volume of the second chamber, and the control means is configured such that at least one of the pressures detected by the first and second pressure detection means is lower than the set pressure, The detecting means detects that the height of the first liquid level is in the first allowable range, and the second liquid level detecting means detects that the height of the second liquid level is in the first allowable range. In this case, the first and second opening / closing means may be controlled such that the first opening / closing means closes the first discharge path and the second opening / closing means closes the second discharge path.

  In this case, since the first and second pressure detection means are used to detect whether or not the pressures in the first chamber and the second chamber are approximately lower than the set pressure, the first and second pressure detection means There is no need to provide a high-performance and expensive pressure gauge as a means.

  At least one of the pressure in the first chamber and the pressure in the second chamber is lower than the set pressure, the height of the first liquid level is in the first allowable range, and the height of the second liquid level is in the first allowable range. In this case, both the first and second discharge paths are closed by the first and second opening / closing means.

  Thereby, the pressure in the first chamber and the second chamber is increased by the first gas and the second gas generated in the first chamber and the second chamber, respectively. Therefore, the pressure in the electrolytic cell can be brought close to the set pressure.

  (6) The first discharge path is further provided with decompression means for decompressing the first chamber, the volume of the first chamber is the same as the volume of the second chamber, and the control means includes the first and second pressures. At least one of the pressures detected by the detecting means is lower than the set pressure, the first liquid level detecting means detects that the first liquid level is in the first allowable range, and the second liquid level detecting means When it is detected that the second liquid level is in the second allowable range, the first opening / closing means closes the first discharge path, and the second opening / closing means closes the second discharge path, The first and second opening / closing means may be controlled.

  In this case, since the first and second pressure detection means are used to detect whether or not the pressures in the first chamber and the second chamber are approximately lower than the set pressure, the first and second pressure detection means There is no need to provide a high-performance and expensive pressure gauge as a means.

  Since the decompression means is provided in the first discharge path, even if the volume of the first chamber and the volume of the second chamber are the same, at least one of the pressure in the first chamber and the pressure in the second chamber is higher than the set pressure. May be lower. When at least one of the pressure in the first chamber and the pressure in the second chamber is lower than the set pressure, the first liquid level is in the first allowable range, and the second liquid level is in the second allowable range, Both the first and second discharge paths are closed by the first and second opening / closing means.

  Thereby, the pressure in the first chamber and the second chamber is increased by the first gas and the second gas generated in the first chamber and the second chamber, respectively. In this case, since the height of the first liquid level is higher than the height of the second liquid level, the pressure difference between the pressure in the first chamber and the pressure in the second chamber is reduced. Moreover, even if no pressure reducing means is provided in the second discharge path, it is possible to prevent the backflow of outside air or the like to the second chamber.

  Therefore, the pressure in the electrolytic cell can be brought close to the set pressure while preventing the first liquid level from decreasing and the backflow of outside air or the like to the second chamber. In this way, the pressure in the electrolytic cell is stably controlled within a certain range while preventing the fluctuation of the liquid level in the electrolytic cell, and the backflow of outside air or the like to the second chamber is prevented. be able to.

  (7) The gas generator further includes a supply path for supplying the compound into the electrolytic cell, and the control means detects that the first liquid level is in the second allowable range by the first liquid level detection means. In addition, when the second liquid level detecting unit detects that the second liquid level is in the second allowable range, the supply path may be controlled so as to supply the compound into the electrolytic cell.

  When the first liquid level is in the second allowable range and the second liquid level is in the second allowable range, the compound is supplied into the electrolytic cell through the supply path. Thereby, the first liquid level and the second liquid level rise. As a result, the first liquid level and the second liquid level can be brought close to the reference liquid level.

  (8) The first liquid level detection means is provided so that the lower end is positioned at the reference liquid level in the first chamber, and the lower end is first in the first chamber. A second probe for detecting the presence or absence of liquid provided to be located at the upper limit height of the first allowable range, and a lower end of the first chamber located at the lower limit height of the second allowable range. And a third probe for detecting the presence or absence of the liquid, and the first liquid level is based on the presence or absence of the liquid detection by the first, second and third probes, and the first allowable range and the second allowable range. A second probe for detecting the presence or absence of liquid, provided so that the lower end is positioned at the reference liquid level in the second chamber; The presence or absence of liquid is detected by providing the lower end of the two chambers at the upper limit height of the first allowable range. 5, and a sixth probe that is provided in the second chamber so that the lower end is positioned at the lower limit height of the second allowable range and detects the presence or absence of liquid. Whether the second liquid level is in the first allowable range or the second allowable range may be detected based on whether or not the liquid is detected by the probe.

  In this case, it is possible to detect whether the first liquid level is in the first allowable range or the second allowable range by the first, second, and third probes. With this probe, it can be detected whether the second liquid level is in the first allowable range or the second allowable range. Therefore, the configuration of the first and second liquid level detecting means is simplified.

  (9) One of the first and second gases may be hydrogen, and the other of the first and second gases may be fluorine.

  In this case, it is possible to stably control the liquid level of the electrolytic bath in the electrolytic cell that generates hydrogen and fluorine with a simple configuration within a certain range.

  According to the present invention, the liquid level of the electrolytic bath in the electrolytic cell can be stably controlled within a certain range with a simple configuration.

It is a schematic diagram which shows the structure of a fluorine gas generator. (A) is a schematic diagram which shows an example of a decompressor. (B) is a schematic diagram which shows the other example of a decompressor. (C) is a schematic diagram showing a configuration of a hydrogen gas exhaust device. (A) is a schematic diagram which shows an example of a decompressor. (B) is a schematic diagram which shows the other example of a decompressor. (C) is a schematic diagram which shows the further another example of a pressure reduction device. It is a schematic diagram for explaining the liquid level control operation in the positive pressure operation state when the volume in the cathode chamber is larger than the volume in the anode chamber. FIG. 5 is a schematic diagram for explaining a liquid level control operation in a negative pressure operation state when the volume in the cathode chamber is larger than the volume in the anode chamber. A phenomenon that occurs when one automatic valve is opened and the other automatic valve is closed when the liquid level in the cathode chamber becomes L level and the liquid level in the anode chamber becomes H level in the negative pressure operation state will be described. It is a schematic diagram for. It is a flowchart which shows the control action by a control apparatus. It is a flowchart which shows the positive pressure operation control by a control apparatus. It is a flowchart which shows the negative pressure operation control by a control apparatus. It is a schematic diagram for explaining the liquid level control operation in the positive pressure operation state when the volume in the cathode chamber is smaller than the volume in the anode chamber. It is a schematic diagram for explaining the liquid level control operation in the negative pressure operation state when the volume in the cathode chamber is smaller than the volume in the anode chamber. It is a figure which shows the summary of the liquid level control operation | movement in a negative pressure operation state.

  Hereinafter, a gas generator according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a fluorine gas generator that generates fluorine gas will be described as an example of a gas generator.

(1) Overall Configuration of Fluorine Gas Generator FIG. 1 is a schematic diagram showing the configuration of a fluorine gas generator according to the present embodiment.

  As shown in FIG. 1, the fluorine gas generator includes an electrolytic cell 1. The electrolytic cell 1 is made of a metal or alloy such as Ni (nickel), monel, pure iron or stainless steel. The electrolytic cell 1 is partitioned into a cathode chamber 3 and an anode chamber 4 by a partition wall 2. The partition wall 2 is made of, for example, a metal or alloy such as Ni, Monel, pure iron, or stainless steel.

  An electrolytic bath 30 made of a KF-HF mixed molten salt is formed in the electrolytic cell 1. A cathode 5 made of, for example, Ni (nickel) is provided in the cathode chamber 3, and an anode 6 made of, for example, low polarizability carbon is provided in the anode chamber 4. HF is supplied to the electrolytic bath 30 in the electrolytic cell 1 through the HF supply pipe 20, and electrolysis of HF is performed. Thereby, hydrogen gas is mainly generated from the cathode 5 of the electrolytic cell 1, and fluorine gas is mainly generated from the anode 6.

  A cathode outlet 7 a is provided in the upper part of the cathode chamber 3. The hydrogen gas generated in the cathode chamber 3 is discharged from the cathode outlet 7a through the hydrogen gas discharge pipe 7. In the hydrogen gas discharge pipe 7, an HF adsorption tower 9, a flow rate adjustment valve 10 and an automatic valve 11 are inserted. A decompression means 12 such as a compressor is connected to the tip of the hydrogen gas discharge pipe 7. The HF adsorption tower 9 is filled with NaF or the like. The HF adsorption tower 9 adsorbs HF from a mixed gas of hydrogen gas and HF discharged from the cathode chamber 3.

  An anode outlet 8 a is provided in the upper part of the anode chamber 4. The fluorine gas generated in the anode chamber 4 is discharged from the anode outlet 8a through the fluorine gas discharge pipe 8. An HF adsorption tower 13, a flow rate adjustment valve 14, and an automatic valve 15 are inserted in the fluorine gas discharge pipe 8. In the present embodiment, a decompression means 16 such as a compressor is connected to the tip of the fluorine gas discharge pipe 8. The HF adsorption tower 13 is filled with NaF or the like. The HF adsorption tower 13 adsorbs HF from the mixed gas of fluorine gas and HF discharged from the anode chamber 4.

  The cathode chamber 3 is provided with a pressure gauge 25 for measuring the pressure in the cathode chamber 3, and the anode chamber 4 is provided with a pressure gauge 26 for measuring the pressure in the anode chamber 4.

  An automatic valve 21 and an orifice 22 are inserted in the HF supply pipe 20. In order to prevent the electrolytic bath 30 from being sucked into the HF supply pipe 20, a bypass valve 23 is connected between the HF supply pipe 20 downstream of the orifice 22 and the hydrogen gas discharge pipe 7. The HF supply pipe 20 is provided with a pressure gauge 27.

  The cathode chamber 3 is provided with a first liquid level detection device 50 </ b> A that detects the liquid level of the electrolytic bath 30, and the anode chamber 4 has a second level that detects the liquid level of the electrolytic bath 30. The liquid level detection device 50B is provided.

  The first liquid level detection device 50A includes three liquid level sensors (probes) 51, 52, and 53. The liquid level sensor 52 is arranged so that the tip thereof is positioned at the reference liquid level in the cathode chamber 3. The liquid level sensor 51 is disposed such that the tip thereof is positioned at a lower limit height lower than the reference liquid level height in the cathode chamber 3. The liquid level sensor 53 is disposed so that the tip thereof is positioned at an upper limit height higher than the reference liquid level height in the cathode chamber 3.

  Similarly, the second liquid level detection device 50B includes three liquid level sensors (probes) 54, 55, and 56. The liquid level sensor 55 is arranged so that the tip thereof is positioned at the reference liquid level in the anode chamber 4. The liquid level sensor 54 is disposed such that the tip thereof is positioned at a lower limit height lower than the reference liquid level height in the anode chamber 4. The liquid level sensor 56 is arranged so that the tip thereof is positioned at an upper limit height higher than the reference liquid level height in the anode chamber 4.

  The upper limit height is the height when the concentration of HF in the electrolytic bath 30 reaches the upper limit, and the lower limit height is the height when the concentration of HF in the electrolytic bath 30 reaches the lower limit.

  Hereinafter, an area between the reference liquid level height and the upper limit height is referred to as an H level, and an area between the reference liquid level height and the lower limit height is referred to as an L level. An area higher than the upper limit height is called an HH level, and an area lower than the lower limit height is called an LL level. The range of the H level and the L level is an allowable range (normal range). When the liquid level of the electrolytic bath 30 reaches the HH level or the LL level, the operation (electrolysis) of the fluorine gas generator is automatically stopped.

  The counter electrodes 50 of the liquid level sensors 51 to 56 are arranged so that their tips are immersed in the electrolytic bath 30. As the counter electrode 50, it is preferable to provide an independent counter electrode 50 as in the present embodiment, but the counter electrode 50 may be in contact with the electrolytic bath 30. For example, the cathode 5 may also serve as the counter electrode 50. .

  The control device 100 applies a voltage for electrolysis between the cathode 5 and the anode 6. The output signals of the pressure gauges 25, 26, and 27, the output signal of the first liquid level detection device 50A, and the output signal of the second liquid level detection device 50B are given to the control device 100. Based on the output signals of the pressure gauges 25, 26, and 27, the output signal of the first liquid level detection device 50A, and the output signal of the second liquid level detection device 50B, the control device 100 automatically valves 11, 15, and 21. And the opening and closing of the bypass valve 23 is controlled. The fluorine gas generator has a button for emergency stop.

  In this embodiment, since there is a potential difference between the cathode 5 made of Ni and the anode 6 made of carbon, when the cathode 5 and the anode 6 coexist in the electrolytic bath 30, Ni of the cathode 5 becomes the electrolytic bath 30. Elute in. Therefore, in order to prevent the cathode 5 from eluting into the electrolytic bath 30 after the electrolysis is stopped, a voltage (about 1.8 V) higher than the above potential difference is applied between the cathode 5 and the anode 6 while the electrolysis is stopped. Apply to.

  As the flow rate adjusting valves 10 and 14, manual needle valves are used. These flow rate adjusting valves 10 and 14 are set to an arbitrary fixed opening. A diaphragm valve or the like can be used in addition to the needle valve, and an orifice may be used instead of these, and a mass flow controller (MFC: mass flow controller) is used instead of these, and the mass flow controller is controlled. The flow rate may be adjusted by being controlled by the apparatus 100.

  FIG. 2A is a schematic diagram illustrating an example of the decompression unit 12, and FIG. 2B is a schematic diagram illustrating another example of the decompression unit 12. FIG. 2C is a schematic diagram showing the configuration of the hydrogen gas exhaust device.

  When the hydrogen gas generated in the cathode chamber 3 is stored in a gas cylinder or supplied to a production line of a factory, as shown in FIG. 2A, the hydrogen gas is discharged downstream of the automatic valve 11 in FIG. A pressure pump 121 is connected to the pipe 7 as the pressure reducing means 12. In this case, when the automatic valve 11 is opened, hydrogen gas generated in the cathode chamber 3 is sucked by the operation of the pressurizing pump 121, and the inside of the cathode chamber 3 is decompressed.

Further, as shown in FIG. 2B, a vacuum generator 122 may be connected to the hydrogen gas discharge pipe 7 downstream of the automatic valve 11 of FIG. In this case, when the automatic valve 11 is opened, the hydrogen gas generated in the cathode chamber 3 is sucked by the ejector effect of the driving N ₂ gas, and the inside of the cathode chamber 3 is decompressed.

When the hydrogen gas generated in the cathode chamber 3 is exhausted to the atmosphere, as shown in FIG. 2C, a hydrogen gas exhaust device 130 is connected to the hydrogen gas discharge pipe 7 downstream of the automatic valve 11 in FIG. Connecting. Accordingly, when the automatic valve 11 is opened, the hydrogen gas is diluted with the diluting N ₂ gas in the hydrogen gas exhaust device 130 and is exhausted to the atmosphere. In this case, the inside of the cathode chamber 3 is opened to atmospheric pressure. 2A to 2C, a small amount of hydrogen contained in the hydrogen gas due to soda lime particles or the like further downstream of the HF adsorption tower 9 of the hydrogen gas discharge pipe 7. It is preferable to provide a detoxification tower (not shown) for removing hydrogen fluoride gas. Furthermore, in an environment where there is no problem with the hydrogen gas concentration, the hydrogen gas from which the hydrogen fluoride gas has been removed may be directly released into the atmosphere.

  3A is a schematic diagram showing an example of the decompression unit 16, FIG. 3B is a schematic diagram showing another example of the decompression unit 16, and FIG. It is a schematic diagram which shows the example of.

  When the fluorine gas generated in the anode chamber 4 is stored in a gas cylinder or supplied to a factory production line or the like, as shown in FIG. 3A, the fluorine gas is discharged downstream of the automatic valve 15 in FIG. A pressure pump 161 is connected to the pipe 8 as the pressure reducing means 16. In this case, when the automatic valve 15 is opened, the fluorine gas generated in the anode chamber 4 is sucked by the operation of the pressurizing pump 161, and the pressure in the anode chamber 4 is reduced.

  Further, as shown in FIG. 3B, a vacuum pump 164 may be connected to the fluorine gas discharge pipe 8 downstream of the automatic valve 15 in FIG. 1 via a container (reactor or the like) 162 and an on-off valve 163. . In this case, for example, an object (not shown) to be reacted with fluorine gas is placed in the container 162, and the inside of the container 162 is evacuated by opening the on-off valve 163 and operating the vacuum pump 164. Here, when the on-off valve 163 is closed and the automatic valve 15 is opened, the fluorine gas generated in the anode chamber 4 is sucked into the container 162 in a vacuum state, and the inside of the anode chamber 4 is decompressed. Thereby, fluorine gas is introduced into the container 162, and the introduced fluorine gas reacts with the object. Alternatively, the high-purity fluorine gas introduced into the container 162 may be supplied to a gas cylinder or a factory production line by evacuating the container 162 by operating the vacuum pump 164. In addition, in the case of multiple use, a vacuum pump is used to prevent failure and ensure safety due to the vacuum pump 164 sucking the fluorine gas or hydrogen fluoride gas remaining in the fluorine gas discharge pipe 8 or the container 162. It is preferable to provide a detoxification tower (not shown) filled with alumina grains or soda lime grains in the vicinity of the upstream side of 164.

Further, as shown in FIG. 3 (c), a vacuum generator 165 may be connected to the fluorine gas discharge pipe 8 downstream of the automatic valve 15 of FIG. In this case, when the automatic valve 15 is opened, the fluorine gas generated in the anode chamber 4 is sucked by the ejector effect of the driving N ₂ gas, and the pressure in the anode chamber 4 is reduced.

(2) Operation of Fluorine Gas Generator Next, the liquid level control operation of the electrolytic bath 30 in the electrolytic cell 1 of the fluorine gas generator of FIG. 1 will be described. In the fluorine gas generator of FIG. 1, control is performed so that the pressure in the electrolytic cell 1 becomes a preset pressure (set pressure). In the present embodiment, the set pressure is atmospheric pressure.

  Hereinafter, a state in which the pressures of both the cathode chamber 3 and the anode chamber 4 in the electrolytic cell 1 are equal to or higher than the atmospheric pressure is referred to as a positive pressure operation state, and the pressure of at least one of the cathode chamber 3 and the anode chamber 4 in the electrolytic cell 1 The state where is lower than the atmospheric pressure is called a negative pressure operation state.

  In the fluorine gas generator of FIG. 1, the liquid level control operation is performed according to the magnitude relationship between the volume in the cathode chamber 3 and the volume in the anode chamber 4, the presence or absence of a decompressor on the cathode outlet 7a side and the anode outlet side 8a, and the operating state. Is different. The volume in the cathode chamber 3 substantially indicates the volume of all spaces from the cathode chamber 3 to the automatic valve 11, and the volume in the anode chamber 4 is substantially automatic from the anode chamber 4. The volume of all the spaces up to the valve 15 is shown.

  First, the liquid level control operation when the volume in the cathode chamber 3 is larger than the volume in the anode chamber 4 will be described with reference to FIGS. 4 to 9, and the volume in the cathode chamber 3 will be described with reference to FIGS. The liquid level control operation when the volume is smaller than the volume in the anode chamber 4 will be described. FIG. 12 summarizes the liquid level control operation in the negative pressure operation state.

  4 to 6 and FIGS. 10 to 12, a state in which the automatic valves 11, 15, and 21 are open is represented by white circles, and a state in which the automatic valves 11, 15, and 21 are closed is represented by black circles. In FIG. 12, “Yin H”, “Yin L”, “Yang H” and “Yang L” indicate that when the liquid level in the cathode chamber 3 is at the H level, the liquid level in the cathode chamber 3 is In the L level, the liquid level in the anode chamber 4 is at the H level, and the liquid level in the anode chamber 4 is at the L level. Further, a state where the automatic valves 11 and 15 are open is represented by “◯”, and a state where the automatic valves 11 and 15 are closed is represented by “X”. “Δ” indicates that normal control is difficult regardless of whether the automatic valves 11 and 15 are opened or closed.

(2-1) Volume in Cathode Chamber 3> Volume in Anode Chamber 4 First, the liquid level control operation in which the volume in the cathode chamber 3 is larger than the volume in the anode chamber 4 will be described.

  FIG. 4 is a schematic diagram for explaining the liquid level control operation in the positive pressure operation state when the volume in the cathode chamber 3 is larger than the volume in the anode chamber 4. FIG. 5 is a schematic diagram for explaining the liquid level control operation in the negative pressure operation state when the volume in the cathode chamber 3 is larger than the volume in the anode chamber 4. 4 and 5, the decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side, and the decompression means 16 is connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side.

(A) Operation in the Positive Pressure Operation State First, the liquid level control operation in the positive pressure operation state will be described with reference to FIG.

  As shown in FIG. 4A, when the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 become H level, both the automatic valve 11 and the automatic valve 15 are opened. Further, the automatic valve 21 is closed. Thereby, hydrogen gas generated in the cathode chamber 3 is discharged from the cathode chamber 3 through the hydrogen gas discharge pipe 7, and fluorine gas generated in the anode chamber 4 is discharged from the anode chamber 4 through the fluorine gas discharge pipe 8. The Further, the inside of the cathode chamber 3 and the inside of the anode chamber 4 are decompressed by the decompression means 12 and 16, respectively. In this case, new HF is not supplied into the electrolytic cell 1. Therefore, the pressure in the electrolytic cell 1 decreases and the pressure in the electrolytic cell 1 approaches atmospheric pressure.

  As shown in FIG. 4B, when the liquid level in the cathode chamber 3 becomes H level and the liquid level in the anode chamber 4 becomes L level, the automatic valve 11 is closed and the automatic valve 15 is opened. Further, the automatic valve 21 is closed. Thereby, hydrogen gas generated in the cathode chamber 3 is retained in the cathode chamber 3. On the other hand, the fluorine gas generated in the anode chamber 4 is discharged from the anode chamber 4 through the fluorine gas discharge pipe 8. Further, the pressure in the anode chamber 4 is reduced by the pressure reducing means 16. Therefore, the liquid level in the cathode chamber 3 is lowered and the pressure in the cathode chamber 3 is lowered. Further, the pressure in the anode chamber 4 decreases, and the liquid level in the anode chamber 4 increases.

  As shown in FIG. 4C, when the liquid level in the cathode chamber 3 becomes L level and the liquid level in the anode chamber 4 becomes H level, the automatic valve 11 is opened and the automatic valve 15 is closed. Further, the automatic valve 21 is closed. Thereby, the fluorine gas generated in the anode chamber 4 is retained in the anode chamber 4. On the other hand, hydrogen gas generated in the cathode chamber 3 is discharged from the cathode chamber 3 through the hydrogen gas discharge pipe 7. Further, the inside of the cathode chamber 3 is decompressed by the decompression means 12. Therefore, the liquid level in the anode chamber 4 decreases and the pressure in the anode chamber 4 decreases. Further, the pressure in the cathode chamber 3 decreases, and the liquid level in the cathode chamber 3 increases.

  In this case, since the electrolytic cell 1 is in a positive pressure operation state, the hydrogen gas in the cathode chamber 3 is sucked by the decompression means 12 so that the inside of the cathode chamber 3 only returns to near atmospheric pressure.

  As shown in FIG. 4D, when the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 become L level, both the automatic valve 11 and the automatic valve 15 are opened. Moreover, the automatic valve 21 is opened. Thereby, hydrogen gas generated in the cathode chamber 3 is discharged from the cathode chamber 3 through the hydrogen gas discharge pipe 7, and fluorine gas generated in the anode chamber 4 is discharged from the anode chamber 4 through the fluorine gas discharge pipe 8. The Further, the inside of the cathode chamber 3 and the inside of the anode chamber 4 are decompressed by the decompression means 12 and 16, respectively. Further, HF is supplied into the electrolytic cell 1 through the HF supply pipe 20. Accordingly, the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 rise, and the pressure in the electrolytic cell 1 decreases. As a result, the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 approach the reference liquid level, and the pressure in the electrolytic cell 1 approaches atmospheric pressure.

  When the decompression means 12 is not connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side, the liquid level in the cathode chamber 3 becomes L level and the liquid level in the anode chamber 4 becomes H level in the positive pressure operation state. When the level is reached, the hydrogen gas in the cathode chamber 3 is released into the atmosphere through the hydrogen gas discharge pipe 7 so that the inside of the cathode chamber 3 only returns to atmospheric pressure.

(B) Operation in the Negative Pressure Operation State Next, referring to FIG. 5, the decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the decompression is performed on the fluorine gas discharge pipe 8 on the anode chamber 4 side. The liquid level control operation in the negative pressure operation state when the means 16 is connected will be described (see the control pattern P1 in FIG. 12).

  As shown in FIG. 5A, when the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 become H level, both the automatic valve 11 and the automatic valve 15 are closed. Further, the automatic valve 21 is closed. Thereby, the pressure in the cathode chamber 3 and the anode chamber 4 is increased by the hydrogen gas and the fluorine gas generated in the cathode chamber 3 and the anode chamber 4, respectively. In this case, new HF is not supplied into the electrolytic cell 1. Therefore, the pressure in the electrolytic cell 1 rises, and the pressure in the electrolytic cell 1 approaches atmospheric pressure.

  As shown in FIG. 5B, when the liquid level in the cathode chamber 3 becomes H level and the liquid level in the anode chamber 4 becomes L level, the automatic valve 11 is closed and the automatic valve 15 is opened. Further, the automatic valve 21 is closed. Thereby, hydrogen gas generated in the cathode chamber 3 is retained in the cathode chamber 3. On the other hand, the fluorine gas generated in the anode chamber 4 is sucked by the decompression means 12 and discharged through the fluorine gas discharge pipe 8. As a result, the liquid level in the cathode chamber 3 is lowered and the liquid level in the anode chamber 4 is raised.

  In this case, since the decompression means 16 is connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side, fluorine gas or other gas does not flow back into the anode chamber 4 through the fluorine gas discharge pipe 8.

  As shown in FIG. 5C, when the liquid level in the cathode chamber 3 becomes L level and the liquid level in the anode chamber 4 becomes H level, both the automatic valve 11 and the automatic valve 15 are closed. Further, the automatic valve 21 is closed. Thereby, the pressure in the cathode chamber 3 and the anode chamber 4 is increased by the hydrogen gas and the fluorine gas generated in the cathode chamber 3 and the anode chamber 4, respectively. In this case, the volume of the anode chamber 4 is smaller than the volume of the cathode chamber 3. Therefore, the pressure difference between the pressure in the anode chamber 4 and the pressure in the cathode chamber 3 is reduced. As a result, the liquid level in the anode chamber 4 is lowered and the liquid level in the cathode chamber 3 is raised. At this time, the liquid level in the anode chamber 4 does not instantaneously drop to the LL level. Details will be described later.

  As shown in FIG. 5D, when the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 become L level, both the automatic valve 11 and the automatic valve 15 are closed. Moreover, the automatic valve 21 is opened. Thereby, the pressure in the cathode chamber 3 and the anode chamber 4 is increased by the hydrogen gas and the fluorine gas generated in the cathode chamber 3 and the anode chamber 4, respectively. Further, HF is supplied into the electrolytic cell 1 through the HF supply pipe 20. As a result, the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 rise.

  In this way, the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 are controlled near the reference liquid level, and the pressure in the electrolytic cell 1 is controlled near atmospheric pressure.

  The liquid level control operation when the decompression means 12 is not connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the decompression means 16 is connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side is: This is the same as the liquid level control operation of FIG. 5 (see control pattern P4 of FIG. 12).

(C) Reason for Liquid Level Control Operation in FIG. 5 (c) Here, as shown in FIG. 5 (c), the liquid level in the cathode chamber 3 becomes L level in the negative pressure operation state, and the inside of the anode chamber 4 The reason why both of the automatic valves 11 and 15 are closed when the liquid level becomes H level will be described.

  FIG. 6 occurs when the automatic valve 11 is opened and the automatic valve 15 is closed when the liquid level in the cathode chamber 3 becomes L level and the liquid level in the anode chamber 4 becomes H level in the negative pressure operation state. It is a schematic diagram for demonstrating the phenomenon to do. FIG. 6A shows a case where the decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side, and FIG. 6B shows the decompression means 12 on the hydrogen gas discharge pipe 7 on the cathode chamber 3 side. Indicates a case where the connection is not established.

  In the case of FIG. 6A, when the automatic valve 11 is opened, the hydrogen gas generated in the cathode chamber 3 is sucked by the decompression means 12 and discharged through the hydrogen gas discharge pipe 7. When the automatic valve 15 is closed, the fluorine gas generated in the anode chamber 4 is retained in the anode chamber 4. Thereby, the liquid level in the cathode chamber 3 rises and the liquid level in the anode chamber 4 falls. In this case, since the volume of the anode chamber 4 is smaller than the volume of the cathode chamber 3, the liquid level in the anode chamber 4 rapidly decreases. Thereby, the liquid level in the anode chamber 4 may be instantaneously lowered to the LL level. Further, the decompression operation state is not preferable, and it is desired to return to the pressurization operation state.

  In the case of FIG. 6B, since the pressure reducing means 12 is not provided in the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the inside of the cathode chamber 3 is in a negative pressure state, the automatic valve 11 is opened. Then, the hydrogen gas and the air flow back through the hydrogen gas discharge pipe 7 into the cathode chamber 3. As a result, the pressure in the cathode chamber 3 rises to atmospheric pressure, and hydrogen gas and air may flow back into the cathode chamber 3 to cause corrosion or the like inside the electrolytic cell 1. On the other hand, when the automatic valve 15 is closed, the pressure in the anode chamber 4 increases due to the generation of fluorine gas. In this case, since the volume of the anode chamber 4 is smaller than the volume of the cathode chamber 3, the liquid level in the anode chamber 4 rises. As a result, the liquid level in the anode chamber 4 may rise to the HH level. Further, the decompression operation state is not preferable, and it is desired to return to the pressurization operation state.

  Therefore, in the present embodiment, when the liquid level in the cathode chamber 3 becomes L level and the liquid level in the anode chamber 4 becomes H level in the negative pressure operation state, as shown in FIG. Both the automatic valve 11 and the automatic valve 15 are closed. Thereby, it is possible to approach the pressurized operation state while preventing the liquid level in the anode chamber 4 having a small volume from changing suddenly.

  Thus, when the volume of the cathode chamber 3 is larger than the volume of the anode chamber 4, the automatic valve 11 on the cathode chamber 3 side is always closed as shown in FIG.

  When the decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the decompression means 16 is not connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side, the control pattern P7 of FIG. It becomes like this. In this case, when the liquid level in the cathode chamber 3 becomes H level and the liquid level in the anode chamber 4 becomes L level, normal liquid level control operation is difficult. That is, when the automatic valve 15 on the anode chamber 4 side is closed, the liquid level in the anode chamber 4 may be lowered to the LL level as in the case of FIG. On the other hand, when the pressure reducing means 16 is not provided in the fluorine gas discharge pipe 8 on the anode chamber 4 side, when the automatic valve 15 on the anode chamber 4 side is opened, fluorine gas or other gas is contained in the anode chamber 4 in the fluorine gas. It flows backward through the discharge pipe 8. In this case, the electrolytic bath 5 and the fluorine gas may be contaminated by the backflowed fluorine gas or other gas.

  Therefore, it is desirable to connect the decompression means 16 to at least the fluorine gas discharge pipe 8 on the anode chamber 4 side and perform the operations of the control patterns P1 and P4.

(D) Control Operation by Control Device 100 Next, a control operation by the control device 100 of FIG. 1 will be described. FIG. 7 is a flowchart showing a control operation by the control device 100 of FIG.

  Here, the opening / closing control of the automatic valves 11, 15, 21 by the control device 100 in the positive pressure operation state is referred to as positive pressure operation control, and the opening / closing control of the automatic valves 11, 15, 21 by the control device 100 in the negative pressure operation state. This is called negative pressure operation control.

  As shown in FIG. 7, first, the control device 100 determines that both the pressure in the cathode chamber 3 and the pressure in the anode chamber 4 of the electrolytic cell 1 are higher than the atmospheric pressure based on the output signals of the pressure gauges 25 and 26. Whether or not (step S1).

  When both the pressure in the cathode chamber 3 and the pressure in the anode chamber 4 of the electrolytic cell 1 are equal to or higher than atmospheric pressure, the control device 100 performs the positive pressure operation control shown in FIG. 4 (step S2). Thereafter, the control device 100 returns to the process of step S1.

  On the other hand, when at least one of the pressure in the cathode chamber 3 and the pressure in the anode chamber 4 of the electrolytic cell 1 is lower than the atmospheric pressure, the control device 100 performs the negative pressure operation control shown in FIG. S3). Thereafter, the control device 100 returns to the process of step S1.

  FIG. 8 is a flowchart showing the positive pressure operation control by the control device 100 of FIG. Here, the opening / closing control of the automatic valves 11, 15, 21 shown in FIG. 4 (a) is referred to as opening / closing control 4a, and the opening / closing control of the automatic valves 11, 15, 21 shown in FIG. 4 (b) is referred to as opening / closing control 4b. The open / close control of the automatic valves 11, 15, 21 shown in FIG. 4C is called an open / close control 4c, and the open / close control of the automatic valves 11, 15, 21 shown in FIG. Call it.

  The control device 100 determines whether the liquid level in the cathode chamber 3 is at the H level or the L level based on the output signal of the first liquid level detection device 50A, and the second liquid level detection device. Based on the output signal of 50B, it is determined whether the liquid level in the anode chamber 4 is at the H level or the L level.

  First, the control device 100 determines whether or not both the liquid levels in the cathode chamber 3 and the anode chamber 4 are at the H level (step S11). When both the liquid levels in the cathode chamber 3 and the anode chamber 4 are at the H level, the control device 100 performs the opening / closing control 4a (control in FIG. 4A) (step S12). If at least one of the liquid levels in the cathode chamber 3 and the anode chamber 4 is not at the H level, the control device 100 proceeds to the process of step S13.

  Next, the control device 100 determines whether or not the liquid level in the cathode chamber 3 is at the H level and the liquid level in the anode chamber 4 is at the L level (step S13). When the liquid level in the cathode chamber 3 is at the H level and the liquid level in the anode chamber 4 is at the L level, the control device 100 performs the opening / closing control 4b (control of FIG. 4B) (step). S14). If the liquid level in the cathode chamber 3 is not at the H level or the liquid level in the anode chamber 4 is not at the L level, the control device 100 proceeds to the process of step S15.

  Next, the control device 100 determines whether or not the liquid level in the cathode chamber 3 is at the L level and the liquid level in the anode chamber 4 is at the H level (step S15). When the liquid level in the cathode chamber 3 is at the L level and the liquid level in the anode chamber 4 is at the H level, the control device 100 performs the opening / closing control 4c (control of FIG. 4C) (step). S16). If the liquid level in the cathode chamber 3 is not at the L level or the liquid level in the anode chamber 4 is not at the H level, the control device 100 proceeds to the process of step S17.

  Further, the control device 100 determines whether or not both the liquid levels in the cathode chamber 3 and the anode chamber 4 are at the L level (step S17). When both the liquid levels in the cathode chamber 3 and the anode chamber 4 are at the L level, the control device 100 performs the opening / closing control 4d (control in FIG. 4D) (step S18). When at least one of the liquid levels in the cathode chamber 3 and the anode chamber 4 is not at the L level, the control device 100 returns to the process of step S1 in FIG.

  FIG. 9 is a flowchart showing negative pressure operation control by the control device 100 of FIG. Here, the opening / closing control of the automatic valves 11, 15, 21 shown in FIG. 5A is referred to as opening / closing control 5a, and the opening / closing control of the automatic valves 11, 15, 21 shown in FIG. 5B is referred to as opening / closing control 5b. The open / close control of the automatic valves 11, 15, 21 shown in FIG. 5C is called an open / close control 5c, and the open / close control of the automatic valves 11, 15, 21 shown in FIG. Call it.

  The control device 100 determines whether the liquid level in the cathode chamber 3 is at the H level or the L level based on the output signal of the first liquid level detection device 50A, and the second liquid level detection device 50B. Based on the output signal, it is determined whether the liquid level in the anode chamber 4 is at the H level or the L level.

  First, the control device 100 determines whether or not both the liquid levels in the cathode chamber 3 and the anode chamber 4 are at the H level (step S21). When both the liquid levels in the cathode chamber 3 and the anode chamber 4 are at the H level, the control device 100 performs the opening / closing control 5a (control in FIG. 5A) (step S22). If at least one of the liquid levels in the cathode chamber 3 and the anode chamber 4 is not at the H level, the control device 100 proceeds to the process of step S23.

  Next, the control device 100 determines whether or not the liquid level in the cathode chamber 3 is at the H level and the liquid level in the anode chamber 4 is at the L level (step S23). When the liquid level in the cathode chamber 3 is at the H level and the liquid level in the anode chamber 4 is at the L level, the control device 100 performs the opening / closing control 5b (control in FIG. 5B) (step). S24). If the liquid level in the cathode chamber 3 is not at the H level or the liquid level in the anode chamber 4 is not at the L level, the control device 100 proceeds to the process of step S25.

  Next, the control device 100 determines whether or not the liquid level in the cathode chamber 3 is at the L level and the liquid level in the anode chamber 4 is at the H level (step S25). When the liquid level in the cathode chamber 3 is at the L level and the liquid level in the anode chamber 4 is at the H level, the control device 100 performs the opening / closing control 5c (control of FIG. 5C) (step). S26). If the liquid level in the cathode chamber 3 is not at the L level or the liquid level in the anode chamber 4 is not at the H level, the control device 100 proceeds to the process of step S27.

  Further, the control device 100 determines whether or not both the liquid levels in the cathode chamber 3 and the anode chamber 4 are at the L level (step S27). When both the liquid levels in the cathode chamber 3 and the anode chamber 4 are at the L level, the control device 100 performs the opening / closing control 5d (control in FIG. 5D) (step S28). When at least one of the liquid levels in the cathode chamber 3 and the anode chamber 4 is not at the L level, the control device 100 returns to the process of step S1 in FIG.

(E) Effects of the above-described liquid level control operation As shown in FIG. 5C, the liquid level in the cathode chamber 3 having a large volume is at the L level and the liquid level in the anode chamber 4 having a small volume is H. In the case of the level, by closing both of the automatic valve 11 on the cathode chamber 3 side and the automatic valve 15 on the anode chamber 4 side, the liquid level in the anode chamber 4 is prevented from abruptly decreasing and the cathode level is reduced. The liquid level in the chamber 3 and the anode chamber 4 can be brought close to the reference liquid level, and the pressure in the electrolytic cell 1 can be brought close to atmospheric pressure.

  Further, as shown in FIG. 5B, when the liquid level in the cathode chamber 3 having a large volume is at the H level and the liquid level in the anode chamber 4 having a small volume is at the L level, the cathode chamber By closing the automatic valve 11 on the 3 side and opening the automatic valve 15 on the anode chamber 4 side, fluorine gas or other gas does not flow back into the anode chamber 4 through the fluorine gas discharge pipe 8, and the cathode chamber 3 and The liquid level in the anode chamber 4 can be brought close to the reference liquid level height.

(2-2) Volume in Cathode Chamber 3 <Volume in Anode Chamber 4 Next, the liquid level control operation when the volume in the cathode chamber 3 is smaller than the volume in the anode chamber 4 will be described.

  FIG. 10 is a schematic diagram for explaining the liquid level control operation in the positive pressure operation state when the volume in the cathode chamber 3 is smaller than the volume in the anode chamber 4. FIG. 11 is a schematic diagram for explaining the liquid level control operation in the negative pressure operation state when the volume in the cathode chamber 3 is smaller than the volume in the anode chamber 4. 10 and 11, a decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side, and a decompression means 16 is connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side.

(A) Operation in Positive Pressure Operation State As shown in FIG. 10, the liquid level control operation in the positive pressure operation state when the volume in the cathode chamber 3 is smaller than the volume in the anode chamber 4 is shown in FIG. As shown, this is the same as the liquid level control operation in the positive pressure operation state when the volume in the cathode chamber 3 is larger than the volume in the anode chamber 4.

(B) Operation in the Negative Pressure Operation State Next, referring to FIG. 11, the decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the decompression is performed on the fluorine gas discharge pipe 8 on the anode chamber 4 side. The liquid level control operation in the negative pressure operation state when the means 16 is connected will be described (see the control pattern P3 in FIG. 12).

  As shown in FIG. 11A, the liquid level control operation when the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 become H level in the negative pressure operation state is shown in FIG. This is the same as the liquid level control operation shown.

  As shown in FIG. 11B, when the liquid level in the cathode chamber 3 becomes H level and the liquid level in the anode chamber 4 becomes L level, both the automatic valve 11 and the automatic valve 15 are closed. Further, the automatic valve 21 is closed. Thereby, the pressure in the cathode chamber 3 and the anode chamber 4 is increased by the hydrogen gas and the fluorine gas generated in the cathode chamber 3 and the anode chamber 4, respectively. In this case, the volume of the cathode chamber 3 is smaller than the volume of the anode chamber 4. Therefore, the pressure difference between the pressure in the cathode chamber 3 and the pressure in the anode chamber 4 is reduced. As a result, the liquid level in the cathode chamber 3 is lowered and the liquid level in the anode chamber 4 is raised. At this time, the liquid level in the cathode chamber 3 does not fall to the LL level for the same reason as in FIG.

  As shown in FIG. 11C, when the liquid level in the cathode chamber 3 becomes L level and the liquid level in the anode chamber 4 becomes H level, the automatic valve 11 is opened and the automatic valve 15 is closed. Further, the automatic valve 21 is closed. Thereby, the fluorine gas generated in the anode chamber 4 is retained in the anode chamber 4. On the other hand, hydrogen gas generated in the cathode chamber 3 is sucked by the decompression means 12 and discharged through the hydrogen gas discharge pipe 7. Thereby, the liquid level in the cathode chamber 3 rises and the liquid level in the anode chamber 4 falls.

  In this case, since the decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side, hydrogen gas or other gas does not flow back into the cathode chamber 3 through the hydrogen gas discharge pipe 7.

  As shown in FIG. 11 (d), the liquid level control operation when the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 become L level in the negative pressure operation state is shown in FIG. 5 (d). This is the same as the liquid level control operation shown.

  In this way, the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 are controlled near the reference liquid level, and the pressure in the electrolytic cell 1 is controlled near atmospheric pressure.

  The liquid level control operation when the decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the decompression means 16 is not connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side is shown in FIG. 11 (see control pattern P9 in FIG. 12).

  When the decompression means 12 is not connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the decompression means 16 is connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side, the control shown in FIG. It becomes like pattern P6. In this case, normal liquid level control operation is difficult when the liquid level in the cathode chamber 3 becomes L level and the level of the liquid level in the anode chamber 4 becomes H level. That is, when the automatic valve 11 on the cathode chamber 3 side is closed, the liquid level in the cathode chamber 3 may be lowered to the LL level. On the other hand, when the pressure reducing means 12 is not provided in the hydrogen gas discharge pipe 7 on the cathode chamber 3 side, when the automatic valve 11 on the cathode chamber 3 side is opened, the hydrogen gas and the atmosphere enter the hydrogen gas discharge pipe 7 in the cathode chamber 3. Back flow through. In this case, the corrosion inside the electrolytic cell 1 is promoted by the moisture in the backflowed atmosphere. Further, water is dissolved in the electrolytic bath 5 and the purity of the generated fluorine gas is lowered.

  Therefore, it is desirable to connect the decompression means 12 to at least the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and perform the operations of the control patterns P3 and P9.

(C) Effects of the above-described liquid level control operation As shown in FIG. 11B, the liquid level in the cathode chamber 3 having a small volume is at the H level and the liquid level in the anode chamber 4 having a large volume is L. In the case of the level, by closing both the automatic valve 11 on the cathode chamber 3 side and the automatic valve 15 on the anode chamber 4 side, the liquid level in the cathode chamber 3 is prevented from drastically lowering, while The liquid level in the chamber 3 and the anode chamber 4 can be brought close to the reference liquid level, and the pressure in the electrolytic cell 1 can be brought close to atmospheric pressure.

  As shown in FIG. 11C, when the liquid level in the cathode chamber 3 having a small volume is at the L level and the liquid level in the anode chamber 4 having a large volume is at the H level, the cathode chamber By opening the automatic valve 11 on the 3 side and closing the automatic valve 15 on the anode chamber 4 side, the hydrogen gas or other gas does not flow back into the cathode chamber 3 through the hydrogen gas discharge pipe 7 and in the cathode chamber 3 and The liquid level in the anode chamber 4 can be brought close to the reference liquid level height, and the pressure in the electrolytic cell 1 can be brought close to the atmospheric pressure.

(2-3) Volume in Cathode Chamber 3 = Volume in Anode Chamber 4 Next, a liquid level control operation when the volume in the cathode chamber 3 and the volume in the anode chamber 4 are equal will be described.

(A) Operation in Positive Pressure Operation State The liquid level control operation in the positive pressure operation state is the same as the liquid level control operation in the positive pressure operation state shown in FIG.

(B) Operation in Negative Pressure Operation State Next, the liquid level control operation in the negative pressure operation state will be described with reference to FIG.

  As shown in FIG. 12, when the decompression means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the decompression means 16 is connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side, The liquid level control operation of P2-1 or the liquid level control operation of control pattern P2-2 is performed.

  In the liquid level control operation of the control pattern P2-1, when the liquid level in the cathode chamber 3 is at the H level and the liquid level in the anode chamber 4 is at the L level, the automatic valve 11 is the same as in the control pattern P1. , 15 are opened and closed. When the liquid level in the cathode chamber 3 is at the L level and the liquid level in the anode chamber 4 is at the H level, the automatic valves 11 and 15 are opened and closed in the same manner as in the control pattern P3.

  In the liquid level control operation of the control pattern P2-2, both automatic valves 11 and 15 are closed in all cases. In this case, the liquid levels in the cathode chamber 3 and the anode chamber 4 do not change. Accordingly, the pressure in the cathode chamber 3 and the anode chamber 4 increases due to the generation of hydrogen gas and fluorine gas, and the state shifts to the positive pressure operation state. Thereby, the operation in the positive pressure operation state described in FIG. 4 is performed.

  When the decompression means 12 is not connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the decompression means 16 is connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side, the control pattern P5-1 The liquid level control operation or the liquid level control operation of the control pattern P5-2 is performed. The liquid level control operation of the control pattern P5-1 is the same as the liquid level control operation in the control pattern P4. Further, the liquid level control operation of the control pattern P5-2 is the same as the control operation of the control pattern P2-2.

  When the pressure reducing means 12 is connected to the hydrogen gas discharge pipe 7 on the cathode chamber 3 side and the pressure reducing means 16 is not connected to the fluorine gas discharge pipe 8 on the anode chamber 4 side, the liquid of the control pattern P8-1 is used. The surface control operation or the liquid level control operation of the control pattern P8-2 is performed. The liquid level control operation of the control pattern P8-1 is the same as the liquid level control operation of the control pattern P9. Further, the liquid level control operation of the control pattern P8-2 is the same as the control operation of the control pattern P2-2.

  In this way, the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 are controlled near the reference liquid level, and the pressure in the electrolytic cell 1 is controlled near atmospheric pressure.

(3) Effect of Embodiment In the fluorine gas generator according to the present embodiment, whether or not the pressure in the cathode chamber 3 and the pressure in the anode chamber 4 are equal to or higher than atmospheric pressure by the pressure gauges 25 and 26. In addition, the first liquid level detection device 50A detects whether the liquid level in the cathode chamber 3 is at the H level or the L level, and the second liquid level detection device 50B detects whether the liquid level in the anode chamber 4 is in the anode chamber 4 or not. Whether the liquid level is at the H level or the L level is detected. Based on these detection results, the opening / closing of the automatic valves 11, 15, 21 is controlled. As a result, the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 are controlled near the reference liquid level, and the pressure in the electrolytic cell 1 is controlled near atmospheric pressure.

  In this case, the pressure gauges 25 and 26 are used to detect whether or not the pressure in the cathode chamber 3 and the pressure in the anode chamber 4 are approximately equal to or higher than atmospheric pressure. It is not necessary to provide a high-performance and expensive pressure gauge capable of detecting the pressure at Further, a complicated pressure control system is not required.

  Further, the first liquid level detection device 50A has a simple configuration including three liquid level sensors 51, 52, and 53, and the second liquid level detection device 50B includes three liquid level sensors 54, 55, 56 has a simple configuration.

  As a result, the liquid level in the cathode chamber 3 and the liquid level in the anode chamber 4 can be brought close to the reference liquid level with a simple configuration, and the pressure in the electrolytic cell 1 can be brought close to atmospheric pressure. .

(4) Other Embodiments In the above embodiment, the set pressure is atmospheric pressure, but the present invention is not limited to this, and the set pressure may be another pressure. The set pressure is preferably atmospheric pressure.

  In the above embodiment, the fluorine gas generator has been described as an example of the gas generator. However, the present invention provides a gas generator that generates other gases such as oxygen gas, nitrogen trifluoride gas, and carbon tetrafluoride gas. Can be applied similarly.

(5) Correspondence between each constituent element of claim and each element of the embodiment Hereinafter, an example of correspondence between each constituent element of the claim and each element of the embodiment will be described. It is not limited to.

  In the above embodiment, one of the cathode chamber 3 and the anode chamber 4 is an example of a first chamber, the other of the cathode chamber 3 and the anode chamber 4 is an example of a second chamber, and the electrolytic cell 1 is an example of an electrolytic cell. And one of the hydrogen gas discharge pipe 7 and the fluorine gas discharge pipe 8 is an example of the first discharge path, and the other of the hydrogen gas discharge pipe 7 and the fluorine gas discharge pipe 8 is an example of the second discharge path. The HF supply pipe 20 is an example of a supply path, one of the automatic valve 11 and the automatic valve 15 is an example of a first opening / closing means, and the other of the automatic valve 11 and the automatic valve 15 is an example of a second opening / closing means. The automatic valve 21 is an example of the third opening / closing means.

  One of the pressure gauge 25 and the pressure gauge 26 is an example of the first pressure detection means, and the other of the pressure gauge 25 and the pressure gauge 26 is an example of the second pressure detection means, and the first liquid level detection. One of the device 50A and the second liquid level detection device 50B is an example of the first liquid level detection means, and the other of the first liquid level detection device 50A and the second liquid level detection device 50B is the second liquid. It is an example of a surface detection means, and the control apparatus 100 is an example of a control means.

Furthermore, atmospheric pressure is an example of a set pressure, one of hydrogen gas and fluorine gas is an example of a first gas, and the other of hydrogen gas and fluorine gas is an example of a second gas,
One of the liquid level sensors 52 and 55 is an example of the first probe, the other of the liquid level sensors 52 and 55 is an example of the fourth probe, and one of the liquid level sensors 53 and 56 is the second probe. For example, the other of the liquid level sensors 53 and 56 is an example of the fifth probe, one of the liquid level sensors 51 and 54 is an example of the third probe, and the other of the liquid level sensors 51 and 54 is the first. It is an example of 6 probes.

  The present invention can be used to generate a gas such as fluorine gas or hydrogen gas by electrolysis.

DESCRIPTION OF SYMBOLS 1 Electrolysis tank 2 Partition 3 Cathode chamber 4 Anode chamber 5 Cathode 6 Anode 7 Hydrogen gas discharge pipe 8 Fluorine gas discharge pipe 7a Cathode outlet 8a Anode outlet 9 HF adsorption tower 10, 14 Flow control valve 11, 15, 21 Automatic valve 12 Depressurization Means 13 HF adsorption tower 16 Pressure reducing means
20 HF supply pipe 22 Orifice 23 Bypass valve 25, 26, 27 Pressure gauge 30 Electrolytic bath 50 Counter electrode 50A, 50B Liquid level detection device 51, 52, 53 Liquid level sensor (probe)
54, 55, 56 Liquid level sensor (probe)
DESCRIPTION OF SYMBOLS 100 Control apparatus 121,161 Pressurization pump 122,165 Vacuum generator 130 Hydrogen gas exhaust apparatus 162 Container (buffer tank)
163 On-off valve 164 Vacuum pump

Claims (9)

A gas generator for generating a first gas and a second gas by electrolysis,
An electrolytic cell that is partitioned into a first chamber and a second chamber and contains an electrolytic bath containing a compound to be electrolyzed;
A first discharge path for discharging the first gas generated in the first chamber;
A second discharge path for discharging the second gas generated in the second chamber;
First opening and closing means for opening and closing the first discharge path;
Second opening and closing means for opening and closing the second discharge path;
First pressure detecting means for detecting the pressure in the first chamber;
Second pressure detecting means for detecting the pressure in the second chamber;
First detecting whether the height of the first liquid level, which is the liquid level in the first chamber, is in the upper first allowable range or the lower second allowable range across the reference liquid level height Liquid level detecting means,
Second liquid level detection means for detecting whether the height of the second liquid level, which is the liquid level in the second chamber, is in the first allowable range or the second allowable range;
The first and second opening / closing means are controlled based on detection results of the first liquid level detecting means, the second liquid level detecting means, and the first pressure detecting means and the second pressure detecting means. A gas generating device comprising: The control means includes
The pressure detected by the first pressure detecting means and the pressure detected by the second pressure detecting means are equal to or higher than a set pressure, and the height of the first liquid level is set by the first liquid level detecting means. When it is detected that the first allowable range is detected and the second liquid level detecting means detects that the height of the second liquid level is within the second allowable range, Controlling the first and second opening / closing means so that the opening / closing means closes the first discharge path and the second opening / closing means opens the second discharge path;
The pressure detected by the first pressure detecting means and the pressure detected by the second pressure detecting means are equal to or higher than a set pressure, and the height of the first liquid level is set by the first liquid level detecting means. When it is detected that the second liquid level is within the second allowable range and the second liquid level detecting means detects that the height of the second liquid level is within the first allowable range, The first and second opening / closing means are controlled so that the opening / closing means opens the first discharge path and the second opening / closing means closes the second discharge path. The gas generator according to 1. The volume of the first chamber is larger than the volume of the second chamber,
The control means is configured such that at least one of the pressures detected by the first and second pressure detection means is lower than a set pressure, and the height of the first liquid level is determined by the first liquid level detection means. When the second liquid level detecting means detects that the second liquid level is within the first allowable range, the first opening / closing is performed. The first and second opening / closing means are controlled so that means closes the first discharge path and the second opening / closing means closes the second discharge path. 2. The gas generator according to 2. The volume of the first chamber is larger than the volume of the second chamber,
The control means is configured such that at least one of the pressures detected by the first and second pressure detection means is lower than a set pressure, and the height of the first liquid level is determined by the first liquid level detection means. The first opening and closing when the second liquid level detection means detects that the second liquid level is within the second allowable range. 2. The first and second opening / closing means are controlled so that means closes the first discharge path and the second opening / closing means opens the second discharge path. 4. The gas generator according to any one of 3. The volume of the first chamber is larger than the volume of the second chamber,
The control means is configured such that at least one of the pressures detected by the first and second pressure detection means is lower than a set pressure, and the height of the first liquid level is determined by the first liquid level detection means. The first opening and closing when the second liquid level detecting means detects that the second liquid level is within the first allowable range. 2. The first and second opening / closing means are controlled so that means closes the first discharge path and the second opening / closing means closes the second discharge path. 4. The gas generator according to any one of 4 above. The first discharge path is further provided with a decompression means for decompressing the first chamber,
The volume of the first chamber is the same as the volume of the second chamber;
The control means is configured such that at least one of the pressures detected by the first and second pressure detection means is lower than a set pressure, and the first liquid level is detected by the first liquid level detection means. And when the second liquid level detecting means detects that the second liquid level is in the second allowable range, the first opening / closing means is the first opening / closing means. 3. The gas generating device according to claim 1, wherein the first and second opening / closing means are controlled such that the discharge path is closed and the second opening / closing means closes the second discharge path. . A supply path for supplying the compound into the electrolytic cell;
The control means detects that the first liquid level is within the second allowable range by the first liquid level detection means, and the second liquid level is detected by the second liquid level detection means. The gas generator according to claim 1, wherein the supply path is controlled so as to supply a compound into the electrolytic cell when it is detected to be within an allowable range of 2. . The first liquid level detection means includes a first probe that is provided so that a lower end thereof is positioned at the reference liquid level in the first chamber and detects the presence or absence of liquid, and a lower end that is positioned in the first chamber. A second probe which is provided to be positioned at an upper limit height of the first allowable range and detects the presence or absence of liquid; and a lower end of the first chamber is positioned at a lower limit height of the second allowable range And a third probe for detecting the presence or absence of liquid, and the first liquid level is determined based on whether or not the liquid is detected by the first, second and third probes. Detecting whether it is within a range and the second tolerance range;
The second liquid level detection means includes a fourth probe that is provided so that a lower end is positioned at the reference liquid level in the second chamber and detects the presence of liquid, and a lower end in the second chamber. A fifth probe that is provided so as to be positioned at the upper limit height of the first allowable range and detects the presence or absence of liquid, and a lower end of the second chamber is positioned at a lower limit height of the second allowable range And a sixth probe for detecting the presence or absence of liquid, and the second liquid level is determined based on whether or not the liquid is detected by the fourth, fifth and sixth probes. The gas generator according to any one of claims 1 to 7, wherein it is detected which of the range and the second allowable range is present. The gas generator according to claim 1, wherein one of the first and second gases is hydrogen, and the other of the first and second gases is fluorine.

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