JP5584904B2 - Fluorine gas generator - Google Patents

Description

  The present invention relates to a fluorine gas generator that generates fluorine gas.

  Conventionally, in a semiconductor manufacturing apparatus, fluorine gas has been used for the purpose of cleaning the inside of the apparatus and etching of a semiconductor substrate, and a fluorine gas generator has been used as a fluorine source of this fluorine gas. A fluorine gas generator has an electrolytic bath having an electrolytic bath made of a molten salt such as hydrogen fluoride, and a device for generating fluorine gas by electrolyzing hydrogen fluoride in the electrolytic bath is known. However, since the electrolytic bath is warmed, mist of the electrolytic bath is generated from the electrolytic bath with the fluorine gas, and this mist passes through the piping and valves, but the piping and valves are blocked by the mist of the electrolytic bath, and the device It is difficult to perform continuous operation. Therefore, in order to prevent clogging by mist, for example, as shown in Patent Document 1 below, before passing the mist of the electrolytic bath accompanying the gas through a valve or the like, the filter is removed in advance and the filter is back-washed. A fluorine gas generation device is known that can clean the mist accumulated on the filter and operate with high operating efficiency even during long-time operation.

  Further, a dehalogenation processing apparatus that suppresses blockage of a discharge pipe or a valve is disclosed in Patent Document 2 below. In this apparatus, since the discharge port provided at the bottom of the reaction tank is closed by the bottom plug valve in a state where it is the same as or protrudes from the bottom of the reaction tank, the liquid to be treated is discharged from the discharge pipe or bottom plug. It is possible to suppress the storage in the valve and increase the processing efficiency.

JP 2005-264231 A JP 2005-319415 A

  However, even in the apparatuses of the above cited references 1 and 2, the electrolytic bath and the liquid to be treated are clogged in the pipe and valve upstream from the filter, the pipe is blocked and the valve is damaged, and the apparatus is operated continuously for a long time. Hateful.

  In addition, even in a hydrogen fluoride supply system that supplies hydrogen fluoride serving as an electrolytic bath into an electrolytic cell, piping may be blocked or a valve may be damaged by hydrogen fluoride. When hydrogen fluoride is not supplied to the electrolytic cell, in the hydrogen fluoride supply system, the piping for supplying hydrogen fluoride gas to the electrolytic cell is evacuated, and then an inert gas is supplied into the piping, and again in the piping. Is repeatedly exhausted to purge the gas inside the pipe. Here, when supplying the inert gas to the hydrogen fluoride gas supply pipe, if the cooled inert gas is supplied from another pipe, the hydrogen fluoride gas remaining inside the valve attached to the other pipe Cooled rapidly and liquefied, corroding the valve seal. Further, when the purge gas is rapidly cooled in the vicinity of the outlet of the pipe that sends the gas to the exhaust port, the hydrogen fluoride contained in the purge gas is liquefied and corrosion of the pipe occurs. In addition, a mass flow controller may be provided in the middle of the piping. When hydrogen fluoride remaining in the mass flow controller is liquefied, the inside of the mass flow controller is corroded and the mass flow controller is damaged. Therefore, the lifetime of these devices is short.

  Further, when hydrogen fluoride is liquefied, the number of moles (molecular weight) per unit volume is increased as compared with the case of gas, and corrosion inside the valve and the mass flow controller is promoted. In addition, since the inside of the valve and the mass flow controller are not straight like a pipe but have many bends, the probability of contact with a hydrogen fluoride liquid is high, and corrosion is further promoted.

  Accordingly, an object of the present invention is to provide a fluorine gas generator capable of suppressing long-term continuous operation while suppressing blockage of piping and damage to equipment such as valves.

  A fluorine gas generator according to the present invention is a fluorine gas generator provided with an electrolytic bath in which an electrolytic bath made of a molten salt containing hydrogen fluoride is housed, and is generated by electrolyzing the electrolytic bath. An exhaust passage through which the contained gas passes and an abatement tower that removes impurities from the fluorine-containing gas, and the exhaust path communicates with the gas phase portion of the electrolytic cell and the abatement tower. It is provided and has a 1st heating means to heat the gas which passes the said discharge path inner wall and / or the said discharge path more than melting | fusing point of the said electrolytic bath.

  According to the above configuration, since the inner wall of the discharge path and / or the discharge path is heated and maintained at the melting point (about 70 ° C.) or higher of the electrolytic bath, for example, about 75 ° C. by the first heating means, the mist scattered from the electrolytic bath When the molten salt passes through the discharge channel, it does not solidify. Therefore, blockage of piping provided in the discharge path and damage to equipment such as a valve and a mass flow controller can be reduced by molten salt scattered from the electrolytic bath, and the fluorine gas generator can be operated continuously for a long period of time.

  A fluorine gas generator according to the present invention includes an electrolytic bath in which an electrolytic bath made of a molten salt containing hydrogen fluoride is accommodated, and a discharge path for passing a fluorine-containing gas generated by electrolyzing the electrolytic bath and / or Alternatively, in the supply path for supplying hydrogen fluoride to the electrolytic cell, solidification of the molten salt contained in the fluorine-containing gas as mist and / or liquefaction of the hydrogen fluoride is suppressed.

  According to the above configuration, the molten salt scattered from the electrolytic bath passes through the discharge path in a gaseous state. Further, hydrogen fluoride passes through the supply path in a gaseous state. For this reason, there is no concern about corrosion of pipes and valves caused by solidification of molten salt or liquefaction of hydrogen fluoride, which occurs with conventional fluorine gas generators, and liquefaction of hydrogen fluoride that occurs with hydrogen fluoride gas supply devices It is possible to prevent the inside of equipment such as valves from being corroded by hydrogen fluoride. Therefore, blockage of piping and damage to devices such as valves and mass flow controllers can be reduced, and the fluorine gas generator can be operated continuously for a long period of time.

  The fluorine gas generator of the present invention has a pressure adjusting valve provided downstream from the detoxification tower, the pressure adjusting valve has a seal portion, and the seal portion has fluorine. It is preferable that a resin is used.

  According to the above configuration, the gas containing fluorine that has passed through the detoxification tower is not heated to a temperature higher than the melting point of the electrolytic bath, and therefore has a temperature lower than the melting point of the electrolytic bath. Since the gas containing fluorine becomes less reactive when the temperature is lower than the melting point of the electrolytic bath, even if it passes through the pressure regulating valve, the fluororesin, for example, PTFE, PCTFE (polyethylene) in the seal portion of the pressure regulating valve. Trifluoroethylene), PVDF (polyvinylidene fluoride), PVF (polyvinyl fluoride), VF2 (vinylidene fluoride), HFP (hexafluoropolypropylene), TFE (tetrafluoroethylene), PMVE (perfluoromethyl vinyl ether) Copolymers using monomers such as are less likely to be eroded, and the life of the pressure regulating valve can be extended.

  Moreover, it is preferable that the said 1st heating means is a heating body provided in contact with the outer wall of the said discharge path, and the said heating body is provided over the full length of the said discharge path. According to this configuration, since the first heating body is provided over the entire length of the discharge path, the temperature of the discharge path can be kept uniform, and melting due to partial excessive temperature rise or insufficient temperature of the discharge path. Solidification of salt and liquefaction of hydrogen fluoride can be suppressed.

  The apparatus further includes a hydrogen fluoride supply device that supplies hydrogen fluoride to the electrolytic bath, and the hydrogen fluoride supply device supplies a hydrogen fluoride supply source and the hydrogen fluoride supply source to the electrolytic cell. A hydrogen fluoride supply path for supplying hydrogen fluoride; a purge gas supply path for introducing an inert gas into the hydrogen fluoride supply path; and a fluorination from the hydrogen fluoride supply path by the introduced inert gas. An inert gas discharge path for discharging hydrogen, and a second heating means for heating the gas passing through the purge gas supply path and the inert gas discharge path to a temperature not lower than the boiling point of hydrogen fluoride. It is preferable to have.

  According to the above configuration, when purging the hydrogen fluoride supply path, the hydrogen fluoride remaining in the equipment such as the purge gas supply path and the inert gas discharge path, valves and valves is not solidified and liquefied. Damage to equipment such as pipes, valves, and mass flow controllers provided in the gas supply path and inert gas discharge path can be suppressed, and the life of these pipes and equipment can be extended. Further, even if the cooled inert gas is introduced from the inlet of the purge gas supply path or the inert gas is rapidly cooled at the outlet of the inert gas discharge path, the inert gas is heated. The hydrogen fluoride remaining inside the piping and equipment is not cooled, and equipment such as piping, valves, and mass flow controllers are not corroded by hydrogen fluoride.

  In the gas generator according to the present invention, the second heating means is a second heating body provided in contact with outer walls of the purge gas supply path and the inert gas discharge path, It is preferable that the heating body is provided over the entire length of the purge gas supply path and the inert gas discharge path. According to this configuration, since the second heating body is provided over the entire length of the purge gas supply path and the inert gas discharge path, the temperature of the purge gas supply path and the inert gas discharge path can be kept uniform. Therefore, it is possible to suppress solid salt solidification and liquefaction of hydrogen fluoride due to partial excessive temperature rise and insufficient temperature in the purge gas supply path and the inert gas discharge path.

  As another aspect, the gas generator according to the present invention further includes a hydrogen fluoride supply device that supplies hydrogen fluoride to the electrolytic bath, and the hydrogen fluoride supply device includes the hydrogen fluoride. A supply source, the hydrogen fluoride supply path, the purge gas supply path, and the inert gas discharge path, and at least a hydrogen fluoride supply source, the hydrogen fluoride supply path, and the purge It is preferable to have the 3rd heating means which heats all with a gas supply path. Here, the heating temperature is preferably higher than the boiling point of hydrogen fluoride (about 20 ° C. or higher). Thereby, the inside of the hydrogen fluoride supply source, the hydrogen fluoride supply path, the purge gas supply path, and the inert gas discharge path can be kept warm above the boiling point of hydrogen fluoride (about 20 ° C. or higher). As a result, even if the environmental temperature at the place where the hydrogen fluoride supply device is installed changes suddenly, the hydrogen fluoride supply source, the hydrogen fluoride supply path, the purge gas supply path, and the inert gas discharge path The hydrogen fluoride present inside does not liquefy. Therefore, corrosion of equipment such as piping and valves due to hydrogen fluoride can be reduced, and the life of these equipment can be extended.

Moreover, the gas generator according to the present invention is a third heating body in which the third heating means is provided in contact with outer walls of the hydrogen fluoride supply path and the purge gas supply path,
It is preferable that the third heating body is provided over the entire length of the hydrogen fluoride supply path and the purge gas supply path. According to this configuration, since the third heating body is provided over the entire length of the hydrogen fluoride supply path and the purge gas supply path, the temperature of the hydrogen fluoride supply path and the purge gas supply path can be kept uniform. Therefore, it is possible to suppress solid salt solidification and liquefaction of hydrogen fluoride due to partial excessive temperature rise and insufficient temperature in the hydrogen fluoride supply path and the purge gas supply path.

  In addition, it is preferable that a part of the hydrogen fluoride supply path from the middle to the electrolytic cell serves as the inert gas discharge path, and can be replaced by the inert gas when the supply of hydrogen fluoride is stopped. . Accordingly, the hydrogen fluoride supply path can be purged with a simple configuration while reducing corrosion of equipment such as piping and valves.

  Furthermore, it is preferable to have a tank heating means for heating the electrolytic bath and a tank cooling means for cooling the electrolytic bath.

  According to the above configuration, since the temperature of the electrolytic cell and the electrolytic bath can be adjusted and controlled to an appropriate temperature by the tank heating unit and the bath cooling unit, the excess of the electrolytic bath due to the supply of hydrogen fluoride to the electrolytic cell, etc. Temperature rise can be suppressed and scattering of mist derived from molten salt can be suppressed. Moreover, it can suppress that members, such as piping and a valve | bulb provided downstream from the electrolytic cell, are clogged with an electrolytic bath. Moreover, the temperature rise of the components which are not shown in figure which comprise the electrolytic cell, for example, a gas seal part, an attached valve, etc. can be suppressed, and the lifetime of these components can be lengthened.

  According to the fluorine gas generator of the present invention, it is possible to prevent the mist-like molten salt scattered from the electrolytic bath and hydrogen fluoride supplied to the electrolytic bath from being liquefied. Thereby, blockage of piping and damage to equipment such as valves can be reduced, and the fluorine gas generator can be operated continuously for a long time. Further, since the inside of the piping and valves of the hydrogen fluoride supply device is heated to the boiling point of hydrogen fluoride or higher, the hydrogen fluoride existing inside the piping and valves does not liquefy. Thus, damage to these devices due to hydrogen fluoride can be reduced, and the life of the components of the hydrogen fluoride supply device can be extended.

It is the schematic of the principal part of the fluorine gas generator by 1st Embodiment of this invention. It is the schematic of the principal part of the fluorine gas generator by reference embodiment of this invention. It is the schematic of the fluorine gas generator by one modification of this invention. It is the schematic of the fluorine gas generator by one modification of this invention. It is the schematic of the fluorine gas generator by one modification of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
Here, a first embodiment of the fluorine gas generator according to the present invention will be described. FIG. 1 is a schematic configuration diagram of a main part of a surface treatment apparatus according to an embodiment of the present invention. In FIG. 1, a fluorine gas generator 100 is included in an electrolytic cell 3 having an anode chamber 1 and a cathode chamber 2, an electrolytic bath 4 accommodated in the electrolytic cell 3, and fluorine gas generated from the anode chamber 1. The first detoxification tower 5a for removing the hydrogen fluoride gas, the second detoxification tower 5b for removing the hydrogen fluoride gas contained in the hydrogen gas generated from the cathode chamber 2, and the downstream of the first detoxification tower 5a The first pressure adjusting valve 6a provided in the second, the second pressure adjusting valve 6b provided downstream from the second detoxification tower 5b, and the fluorine gas generation provided on the anode chamber 1 side of the electrolytic cell 3 A first pipe 8a connected between the port 7a and the first abatement tower 5a, a hydrogen gas generation port 7b provided on the cathode chamber 2 side of the electrolytic cell 3, and a second abatement tower 5b. It has the 2nd piping 8b connected between. Here, the discharge path 11a is comprised by the electrolytic cell edge cutting valve 9a, the 1st piping 8a, and the detoxification tower inlet edge cutting valve 10a, and the electrolytic cell edge cutting valve 9b, the 2nd piping 8b, and the detoxification tower inlet edge cutting valve 10b are comprised. A discharge path 11b is configured. The discharge paths 11a and 11b are provided with a first line heater 12a and a second line heater 12b, respectively. An electrolytic bath warming heater 13 is provided outside the electrolytic bath 3, and an electrolytic bath warming heater protective cover 14 is further provided outside the electrolytic bath 3 and the electrolytic bath warming heater 13. Yes. A cooling fan 15 is provided in the vicinity of the electrolytic cell 3.

  The electrolytic cell 3 is made of a metal or alloy such as Ni, Monel, pure iron, or stainless steel. The electrolytic cell 3 is separated into an anode chamber 1 and a cathode chamber 2 by a partition wall 16 made of monel or the like. An anode 17 is disposed in the anode chamber 1. It is preferable to use a low polarizable carbon electrode or Ni (nickel) for the anode 17. A cathode 18 is disposed in the cathode chamber 2. The cathode 18 is preferably made of Ni or iron. The distance between the anode 17 and the partition 16 and the distance between the cathode 18 and the partition 16 are preferably substantially the same. As a result, the dissolution of the partition wall 16 caused by the bipolarization can be prevented, and the life extension effect of the electrolytic cell 3 can be obtained. On the upper lid of the electrolytic cell 3, a partition wall 16 separating the electrolytic cell 3 into the anode chamber 1 and the cathode chamber 2, a fluorine gas generating port 7 a for fluorine gas generated from the anode chamber 1, and the cathode chamber 2 are generated. Hydrogen gas generating port 7b for hydrogen gas to be generated, and a hydrogen fluoride introducing port into which a hydrogen fluoride supply pipe 31 for hydrogen fluoride supplied to the electrolytic bath 4 when the liquid level of the electrolytic bath 4 is lowered is inserted (Not shown), a first liquid level detection sensor 19 for detecting the liquid level of the electrolytic bath 4 in the anode chamber 1, and a second second liquid level detection for detecting the liquid level in the cathode chamber 2 in five stages. A sensor 20, a pressure gauge 21 that measures the pressure in the anode chamber 1, a pressure gauge 22 that measures the pressure in the cathode chamber 2, and a thermometer (not shown) for measuring the temperature of the electrolytic bath 4 are provided.

The electrolytic bath 4 is a mixed molten salt of potassium fluoride-hydrogen fluoride or ammonium fluoride-hydrogen fluoride, and is filled inside the electrolytic bath 3. Since many of the mixed molten salts used for the electrolytic bath 4 have a melting point higher than room temperature, an electrolytic bath heating heater 13 is provided on the outer periphery of the electrolytic bath 3. Examples of the melting point of the mixed molten salt used in the electrolytic bath 4 include, for example, about 70 ° C. (KF · 2HF) and about 50 ° C. (NH ₄ F · 2HF).

  The first abatement tower 5 a is for removing unnecessary components generated from the anode chamber 1. The first detoxification tower 5a is, for example, a case where hydrogen fluoride is contained in the electrolytic bath 4, and when generating fluorine gas by electrolysis, a material having corrosion resistance to fluorine gas and hydrogen fluoride, for example, , Stainless steel, monel, and Ni (nickel). Moreover, the inside of the 1st removal tower 5a is filled with removal agents, such as sodium fluoride (henceforth NaF), and removes hydrogen fluoride contained in the introduced fluorine gas. The fluorine gas from which hydrogen fluoride has been removed is led out through the lead-out path 23a downstream of the first detoxification tower.

The second abatement tower 5b removes unnecessary components generated from the cathode chamber 2, and, for example, hydrogen fluoride is contained in the electrolytic bath 4 as in the first abatement tower 5a described above. When hydrogen gas is generated by electrolysis, it is preferably formed of a material having corrosion resistance to fluorine gas and hydrogen fluoride, such as stainless steel, monel, and Ni. Also, inside the second Jogaito 5b are loaded is NaF and CaCO _3, etc., is to remove the hydrogen fluoride contained in the introduced gas. The hydrogen gas from which hydrogen fluoride has been removed is led out through the lead-out path 23b downstream of the second detoxification tower 5b.

  The first pressure regulating valve 6a is provided in the middle of the outlet passage 23a downstream from the first detoxification tower 5a, and opens and closes according to the pressure of the pressure gauge 21 to regulate the pressure in the anode chamber 1. Is. Thereby, it can suppress that the anode chamber 1 becomes pressure reduction. The first pressure regulating valve 6a has a seal portion (not shown), and a fluororesin is used for the seal portion. For example, PTFE (tetrafluoroethylene resin), PCTFE (poly 3 Ethylene fluoride), PVDF (polyvinylidene fluoride), PVF (polyvinyl fluoride), VF2 (vinylidene fluoride), HFP (hexafluoropolypropylene), TFE (tetrafluoroethylene), PMVE (perfluoromethyl vinyl ether), etc. Copolymers using monomers can be used. When the seal portion having such a material is provided, the seal portion (not shown) is hardly eroded by fluorine gas passing through the first pressure regulating valve 6a or hydrogen fluoride contained in the fluorine gas, The life of the first pressure regulating valve 6a can be further extended. The seal portion is a portion that functions as a deadline when the first pressure adjusting valve 6a is closed by joining the metal member and the resin member constituting the first pressure adjusting valve 6a. Examples of the adjusting valve 6a include a diaphragm valve and a bellows valve. Further, in addition to the closing at the time of the closing operation described above, a seal portion for cutting the edge between the outside of the first pressure regulating valve 6a and the inside of the first pressure regulating valve 6a by joining the metal member and the resin member may be used. The pressure adjustment valve 6a may be a ball valve or the like having a seal portion for cutting the edge.

  The second pressure regulating valve 6b is provided in the middle of the outlet path 23b downstream from the second detoxification tower 5b, and is interlocked according to the pressure of the pressure gauge 22 in the same manner as the first pressure regulating valve 6a described above. The pressure in the cathode chamber 2 is adjusted by opening and closing. Thereby, it can suppress that the cathode chamber 2 becomes pressure reduction. Similarly to the first pressure adjustment valve 6a, the second pressure adjustment valve 6b also has a seal portion (not shown), and this seal portion is made of fluororesin. For example, PTFE, PCTFE (polyester) Trifluoroethylene), PVDF (polyvinylidene fluoride), PVF (polyvinyl fluoride), VF2 (vinylidene fluoride), HFP (hexafluoropolypropylene), TFE (tetrafluoroethylene), PMVE (perfluoromethyl vinyl ether) Copolymers using monomers such as can be used. When the seal portion having such a material is provided, the seal portion (not shown) is less likely to be eroded by fluorine gas passing through the second pressure regulating valve 6b or hydrogen fluoride contained in the fluorine gas, The lifetime of the second pressure regulating valve 6b can be further extended.

  The first pipe 8a is a pipe provided between the fluorine gas generation port 7a and the first abatement tower 5a so as to communicate the gas phase portion of the anode chamber 1 and the first abatement tower 5a. It is connected. The first line heater 12a provided in the first pipe 8a uniformly warms the inner walls of the first pipe 8a and the first pipe 8a, and the gas passing through the first pipe 8a is the melting point of the electrolytic bath 4. It is heated and maintained at (about 70 ° C.) or higher, for example, about 75 ° C.

  The second pipe 8b is a pipe provided between the hydrogen gas generation port 7b and the second removal tower 5b, and communicates the gas phase portion of the cathode chamber 2 with the second removal tower 5b. It is connected. The temperature inside the second pipe 8b and the second pipe 8b is uniformly warmed by the second line heater 12b provided in the second pipe 8b, and the gas passing through the second pipe 8b is the melting point of the electrolytic bath 4. It is heated and maintained at about 75 ° C. above (about 70 ° C.).

  The first line heater 12a is an exhaust gas provided with an electrolytic cell edge cutting valve 9a, a first pipe 8a, and a removal tower inlet edge cutting valve 10a over the entire length from the fluorine gas generation port 7a to the first removal tower 5a inlet. The path 11a is provided so as to be spirally wound. As shown in FIG. 1, the 1st line heater 12a is provided in contact with the outer wall of the electrolytic cell edge cutting valve 9a, the 1st piping 8a, and the abatement tower inlet edge cutting valve 10a. By this first line heater 12 a, the inner wall of the discharge path 11 a and / or the inside of the discharge path 11 a is maintained and heated uniformly above the melting point of the electrolytic bath 4. Thereby, it can suppress that the mist originating in the electrolytic bath 4 which generate | occur | produced from the fluorine gas generation port 7a is solidified in the discharge path 11a, and is between the vapor phase part of the anode chamber 1 and the 1st detoxification tower 5a. It is possible to prevent the molten salt from clogging the electrolytic cell edge cutting valve 9a, the first pipe 8a, and the detoxification tower inlet edge cutting valve 10a provided in the discharge passage 11a. The first line heater 12a is not limited to the one provided to be wound as shown in the present embodiment, but is in contact with or close to the first pipe 8a along the extending direction of the first pipe 8a. It is also possible to use a linear one, a spiral one, or a belt-like one wound around. Further, the first line heater 12a is preferably configured to increase the heating amount according to the heat capacity of a portion having a large heat capacity such as a valve portion. Further, as the first line heater 12a, for example, a normal heater including a heating wire, a ribbon heater that is insulated with silicon rubber, or the like may be used.

  The second line heater 12b is a discharge path provided with an electrolytic cell edge cutting valve 9b, a second pipe 8b, and a removal tower inlet edge cutting valve 10b in the entire length from the hydrogen gas generation port 7b to the second removal tower 5b inlet. 11b is provided so as to be spirally wound. As shown in FIG. 1, the 2nd line heater 12b is provided in contact with the outer wall of the electrolytic cell edge cutting valve 9b, the 1st piping 8b, and the abatement tower inlet edge cutting valve 10b. By the second line heater 12b, the inner wall of the discharge passage 11b and / or the inside of the discharge passage 11a are maintained and heated uniformly above the melting point of the electrolytic bath 4. Thereby, it can suppress that the mist originating in the electrolytic bath 4 which generate | occur | produced from the hydrogen gas generation port 7b solidifies in the discharge path 11b, and is between the gaseous-phase part of the anode chamber 1 and the 2nd detoxification tower 5b. It is possible to prevent the molten salt from clogging the electrolytic cell edge cutting valve 9b, the second pipe 8b, and the detoxification tower inlet edge cutting valve 10b provided in the discharge passage 11b. Similar to the first line heater 12a, the second line heater 12b is not limited to the one provided to be wound as shown in the present embodiment, but in a direction parallel to the length direction of the second pipe 8b. Also, it may be attached to the second pipe 8b. Moreover, you may use a normal heater etc. as the 2nd line heater 12b, for example.

  The electrolytic bath warming heater 13 is provided so as to surround the side surface of the electrolytic bath 3 and heats the electrolytic bath 4 through the electrolytic bath 3.

  The electrolytic bath warming heater protective cover 14 is provided so as to cover the side surface of the electrolytic bath 3 and the outer periphery of the electrolytic bath warming heater 13. The electrolytic bath warming heater protective cover 14 is provided with a space from the electrolytic bath warming heater 13.

  The cooling fan 15 is provided in the vicinity of the electrolytic bath 3. Air is sent from the outside between the electrolytic bath warming heater 13 and the electrolytic bath warming heater protective cover 14, and the electrolytic bath 3 and the electrolytic bath 4. Is adjusted to an appropriate temperature and controlled. Thereby, it is suppressed that the electrolytic cell 3 and the electrolytic bath 4 become too high temperature. Further, when the temperature of the electrolytic cell 3 rises, the temperature of a resin sealing material (not shown) or an insulating sheet (not shown) provided between the lid of the electrolytic cell 3 and the main body of the electrolytic cell 3 increases. The temperature rises and the durability of the resin sealing material (not shown) or the insulating sheet (not shown) may be reduced, but cooling with the cooling fan 15 suppresses the temperature rise of the electrolytic cell 3. Therefore, durability of these sealing materials and insulating sheets can be improved. Instead of the cooling fan, other air cooling means or water cooling means can be used as the tank cooling means. In particular, air cooling means such as a cooling fan used in the present embodiment is preferably used. Note that it is preferable to install a plurality of cooling fans in preparation for occurrence of cooling failure due to failure or the like.

  One end of the hydrogen fluoride supply pipe 31 is connected to the hydrogen fluoride supply device 30, and the other end is located in the electrolytic bath 4 of the cathode chamber 2 of the electrolytic cell 3. Then, the hydrogen fluoride gas supplied from the hydrogen fluoride supply device 30 is supplied to the electrolytic bath 4. The hydrogen fluoride supply device 30 has a hydrogen fluoride gas cylinder. Hydrogen fluoride introduced into the electrolytic cell 3 from the hydrogen fluoride supply pipe 31 is dissolved in the electrolytic bath 4 and electrolyzed.

  In the present embodiment, a pipe for introducing an inert gas into the gas phase portion of the cathode chamber 2 of the electrolytic cell 3 may be provided. As a result, when the liquid level of the electrolytic bath 4 in the cathode chamber 2 becomes higher than that of the anode chamber 1, an inert gas is introduced into the electrolytic bath 3, and the liquid level of the electrolytic bath 4 is kept low. The liquid level can be controlled. For example, nitrogen gas can be used as the inert gas.

  Next, the flow of gas generated from the electrolytic cell 3 when the fluorine gas generator 100 of this embodiment is operated will be described. Electrolysis of the electrolytic bath 4 is performed, and the gas containing fluorine gas and hydrogen fluoride generated from the anode chamber 1 and staying in the anode chamber 1 is combined with the mist-like molten salt scattered from the electrolytic bath 4 and the fluorine gas generating port 7a. Released from. And it passes along the discharge path 11a which has the electrolytic cell edge cutting valve 9a, the 1st piping 8a, and the removal tower entrance edge cutting valve 10a, and is guide | induced to the 1st removal tower 5a. Here, the inside of the electrolytic cell edge cutting valve 9a, the first piping 8a, and the detoxification tower inlet edge cutting valve 10a is heated and maintained above the melting point of the electrolytic bath 4 by the first line heater 12a. The gas is guided to the first detoxification tower 5a in a liquid state, and liquefaction of hydrogen fluoride and solidification of mist in the gas containing fluorine gas are suppressed. Then, the hydrogen fluoride is removed by the first detoxification tower 5a and guided to the outside of the fluorine gas generator 100.

  On the other hand, in the cathode chamber 2, the electrolytic bath 4 is electrolyzed, and the hydrogen gas generated from the cathode chamber 2 and the gas containing hydrogen fluoride is melted in the form of mist scattered from the electrolytic bath 4. It is discharged from the hydrogen gas generating port 7b together with the salt. And it passes along the discharge path 11b which has the electrolytic cell edge cutting valve 9b, the 2nd piping 8b, and the removal tower entrance edge cutting valve 10b, and is guide | induced to the 2nd removal tower 5b. Here, the inside of the electrolytic cell edge cutting valve 9b, the second pipe 8b, and the detoxification tower inlet edge cutting valve 10b is heated and maintained above the melting point of the electrolytic bath 4 by the second line heater 12b. The gas is guided to the second detoxification tower 5b in a liquid state, and liquefaction of hydrogen fluoride and solidification of mist in the gas containing fluorine gas are suppressed. Then, the hydrogen fluoride is removed by the second detoxification tower 5b and guided to the outside of the fluorine gas generator 100.

  According to the present embodiment, the inner wall and / or the discharge path of the discharge path 11a provided with the electrolytic cell edge cutting valve 9a, the first pipe 8a, and the detoxification tower inlet edge cutting valve 10a by the first line heater 12a and the second line heater 12b. 11a and the inner wall of the discharge passage 11b and / or the inside of the discharge passage 11b provided with the electrolytic cell edge cutting valve 9b, the second pipe 8b and the detoxification tower inlet edge cutting valve 10b are heated to the melting point (about 70 ° C.) or more of the electrolytic bath 4 Therefore, the mist-like molten salt scattered from the electrolytic bath 4 does not solidify when contacting the inner walls of the discharge passages 11a and 11b and / or passing through the discharge passages 11a and 11b. As a result, the first pipe 8a and the second pipe 8b provided in the discharge passages 11a and 11b are blocked, the electrolytic cell edge cutting valves 9a and 9b, the detoxification tower inlet edge cutting valves 10a and 10b are not damaged, and fluorine gas is generated. The apparatus 100 can be operated continuously for a long time.

  Further, the gas that has passed through the first detoxification tower 5 a and the second detoxification tower 5 b is not heated to a temperature higher than the melting point of the electrolytic bath 4, so that the temperature is lower than the melting point of the electrolytic bath 4. Since the gas containing fluorine becomes less reactive when the temperature is lower than the melting point of the electrolytic bath 4, even if it passes through the first pressure adjusting valve 6a and the second pressure adjusting valve 6b, the fluorine in the seal portion of the valve The resin is not eroded, and the life of the first pressure regulating valve 6a and the second pressure regulating valve 6b can be extended.

  Further, the first line heater 12a is provided over the entire length of the discharge path 11a provided with the electrolytic cell edge cutting valve 9a, the first pipe 8a, and the detoxification tower inlet edge cutting valve 10a, and the electrolytic cell edge cutting valve 9b, the second Since the second line heater 12b is provided over the entire length of the discharge path 11b provided with the pipe 8b and the removal tower inlet edge cutting valve 10b, the electrolytic cell edge cutting valve 9a, the first pipe 8a and the removal tower inlet edge cutting are provided. The temperature of the discharge path 11a provided with the valve 10a, the electrolytic cell edge cutting valve 9b, the second pipe 8b, and the discharge path 11b provided with the detoxification tower inlet edge cutting valve 10b can be kept uniform, and the discharge paths 11a and 11b. The occurrence of partial temperature unevenness or solidification of the molten salt due to insufficient temperature can be suppressed.

  The temperature of the electrolytic bath 3 and the electrolytic bath 4 can be adjusted and controlled to an appropriate temperature by the electrolytic bath warming heater 13 and the cooling fan 15, so that the electrolytic bath 4 caused by the supply of hydrogen fluoride to the electrolytic bath, etc. An excessive increase in temperature can be suppressed and scattering of mist derived from the electrolytic bath 4 can be suppressed. As a result, the electrolyzer edge cutting valves 9a and 9b, the first pipe 8a, the second pipe 8b, the detoxification tower inlet edge cutting valves 10a and 10b, the first pressure adjusting valve 6a, 2 It is possible to prevent clogging of members such as the pressure adjusting valve 6b by the electrolytic bath 4. Moreover, the temperature rise of the components which are not shown in figure which comprise the electrolytic cell 3, for example, a gas seal part, an attached valve, etc. can be suppressed, and the lifetime of these components can be made longer.

[Reference embodiment]
Next, a second embodiment of the fluorine gas generator according to the present invention will be described. FIG. 2 is a schematic configuration diagram of a fluorine gas generator according to a reference embodiment of the present invention. In addition, about the thing similar to 1st Embodiment, it shows with the same code | symbol and abbreviate | omits description.

  As shown in FIG. 2, the fluorine gas generation device 200 in the present embodiment uses a hydrogen fluoride supply device 230 instead of the hydrogen fluoride supply device 30 in the first embodiment, and is connected to the hydrogen fluoride supply pipe 31. A heater 232 is wound. Further, the first line heater 12a, the second line heater 12b, the electrolytic bath warming heater 13, the electrolytic bath warming heater protective cover 14 and the cooling fan 15 are not attached. Other than this, the description is omitted because it is almost the same as the first embodiment.

  The hydrogen fluoride supply device 230 includes a hydrogen fluoride cylinder 251, a hydrogen fluoride supply pipe 31, a purge gas supply pipe 253, a vent pipe 254, and a cabinet 255. A hydrogen fluoride cylinder cutting valve 256 is attached to the inlet of the hydrogen fluoride cylinder 251. Further, an edge cutting valve 257 is provided in the middle of the hydrogen fluoride supply pipe 31, an edge cutting valve 258 is provided in the middle of the purge gas supply pipe 253, and an edge cutting valve 259 is provided in the middle of the vent pipe 254. Yes.

  The hydrogen fluoride cylinder 251 is a source of hydrogen fluoride supplied to the electrolytic bath 4. Heaters 271 and 272 are disposed on the bottom and side surfaces of the hydrogen fluoride cylinder 251, respectively. The heater 271 is disposed so as to cover the entire bottom surface of the hydrogen fluoride cylinder 251. The heater 272 surrounds substantially the entire side surface of the hydrogen fluoride cylinder 251. By the heater 271 and the heater 272, the inside of the hydrogen fluoride cylinder 251 is maintained at a temperature equal to or higher than the boiling point of hydrogen fluoride. Thus, hydrogen fluoride inside the hydrogen fluoride cylinder 251 can be stored in a gaseous state, and hydrogen fluoride gas can be supplied from the hydrogen fluoride cylinder 251. Moreover, the gas pressure by the hydrogen fluoride in the hydrogen fluoride cylinder 251 can be raised to a pressurized state so that the hydrogen fluoride gas itself is supplied by the gas pressure.

  One end of the hydrogen fluoride supply pipe 31 is connected to the hydrogen fluoride cylinder 251 through a hydrogen fluoride cylinder edge cut-off valve 256. The other end is disposed in the electrolytic bath 4 on the cathode chamber 2 side of the electrolytic cell 3. When the edge cutting valve 257 is closed, the flow of fluorine gas from the hydrogen fluoride cylinder 251 stops. The hydrogen fluoride supply pipe 31 and the edge cut valve 257 constitute a hydrogen fluoride supply path.

  One end of the purge gas supply pipe 253 is connected to a nitrogen gas source (not shown). The nitrogen gas source is disposed outside the cabinet 255, and in this embodiment, nitrogen gas is used as the purge gas. The other end of the purge gas supply pipe 253 is connected to the hydrogen fluoride supply pipe 31, and is connected between the edge cutting valve 256 and the hydrogen fluoride edge cutting valve 257 in the hydrogen fluoride supply pipe 31. The purge gas supply pipe 253 and the edge cut valve 258 constitute a nitrogen gas supply path. When the edge cut valve 258 is closed, the flow of nitrogen gas from the nitrogen gas source stops. Nitrogen gas is introduced when the hydrogen fluoride supply pipe 31 is purged or when the hydrogen fluoride gas is discharged from the hydrogen fluoride supply pipe 31. Nitrogen gas introduced from the nitrogen gas source into the purge gas supply pipe 253 is guided to the hydrogen fluoride supply pipe 31, and the hydrogen fluoride remaining in the hydrogen fluoride supply pipe 31 is guided to the vent pipe 254.

  The vent pipe 254 has one end connected to a vent port (discharge port) (not shown) and the other end connected to a purge gas supply tube 253. The other end is connected to a position downstream of the edge cut valve 258 in the purge gas supply pipe 253. The vent pipe 254 and the edge cutting valve 259 constitute a nitrogen gas purge path. The hydrogen fluoride gas discharged from the hydrogen fluoride supply pipe 31 flows through the vent pipe 254. This hydrogen fluoride gas is a gas discharged from the hydrogen fluoride supply pipe 31 by nitrogen gas, and nitrogen gas is also mixed. The hydrogen fluoride gas that has flowed through the vent pipe 254 is guided to the vent port and released to the outside of the cabinet 255.

  The line heater 232 is attached to the side surfaces of the hydrogen fluoride supply pipe 31, the purge gas supply pipe 253, and the vent pipe 254 by being spirally wound over the entire length of the pipe. The line heater 232 attached to the hydrogen fluoride supply pipe 31 is attached from the hydrogen fluoride cylinder edge cutting valve 256 to the inlet of the electrolytic cell 3, and is also wound around the hydrogen fluoride cylinder edge cutting valve 256 and the edge cutting valve 257. The line heater 232 attached to the purge gas supply pipe 253 is attached from the inlet of a nitrogen source (not shown) to the connection portion with the hydrogen fluoride supply pipe 31 and is also wound around the edge cutting valve 258. The line heater 232 attached to the vent pipe 254 is attached from the discharge port (not shown) of the cabinet 255 to the connection portion with the purge gas supply pipe 253, and is also wound around the edge cutting valve 259. As shown in FIG. 2, the line heater 232 includes a hydrogen fluoride supply pipe 31, a purge gas supply pipe 253, a vent pipe 254, a hydrogen fluoride cylinder edge cutting valve 256, an edge cutting valve 257, and an edge cutting valve 258. And in contact with the outer wall of the edge cut valve 259. By this line heater 232, the inner walls and the interior of the hydrogen fluoride supply pipe 31, the purge gas supply pipe 253, and the vent pipe 254 are uniformly heated above the boiling point of hydrogen fluoride (about 20 ° C. or more). Further, the insides of the hydrogen fluoride cylinder edge cutting valve 256 and the edge cutting valves 257, 258, and 259 are also uniformly heated to the boiling point of hydrogen fluoride or higher. In addition, since the boiling point of hydrogen fluoride changes with the internal pressure in the piping, it is preferable to set the temperature for heating (heating temperature of the line heater 232) assuming a possible pressure in the piping.

  Similar to the first line heater and the second line heater of the first embodiment, the line heater 232 is provided with a linear heater or a spiral heater in contact with the pipe along the extending direction of the pipe, or close to it. May be provided. Moreover, you may wind a strip | belt-shaped heater around the side surface of piping. Moreover, it is preferable to set so that the heating amount may be increased according to the heat capacity at a portion having a large heat capacity such as the hydrogen fluoride cylinder edge cutting valve 256 and the edge cutting valves 257, 258, and 259. Instead of the line heater 232, for example, a normal heater including a heating wire, a ribbon heater that is covered with silicon rubber, or the like may be used.

  The cabinet 255 stores a hydrogen fluoride cylinder 251, a hydrogen fluoride supply pipe 31, a purge gas supply pipe 253, and a vent pipe 254. In addition, the cabinet 255 is formed with an air supply port 261 for supplying air into the cabinet 255 and an air discharge port 262 for discharging the air inside the cabinet 255. Then, when hydrogen fluoride gas or nitrogen gas leaks from the hydrogen fluoride cylinder 251, piping and valves, it is discharged from the air discharge port 262, and then air is introduced from the air supply port 261, and the environment in the cabinet 255 is adjusted. . The cabinet 255 is a movable housing, and the installation location of the hydrogen fluoride supply device 230 can be changed according to a change in environmental temperature.

  Next, the operation of the hydrogen fluoride supply device 230 and the gas flow when the fluorine gas generation device 200 in the present embodiment is operated will be described.

  In order to supply hydrogen fluoride from the hydrogen fluoride supply device 230 to the cathode chamber 2, the edge cutting valve 258 and the edge cutting valve 259 are closed, and the hydrogen fluoride gas cylinder edge cutting valve 259 and the edge cutting valve 259 are opened. As a result, the hydrogen fluoride gas in the hydrogen fluoride cylinder 251 passes through the hydrogen fluoride supply pipe 31 and is introduced into the cathode chamber 2. At this time, since the inner wall and the inside of the hydrogen fluoride supply pipe 31 are heated to the boiling point of hydrogen fluoride or more by the line heater 232, the hydrogen fluoride passing through the hydrogen fluoride supply pipe 31 is not liquefied.

  When electrolysis of the molten salt containing hydrogen fluoride is performed in the electrolytic cell 3, fluorine gas containing hydrogen fluoride is generated in the anode chamber 1, and the generated fluorine gas is released from the fluorine gas generating port 7a. Is done. These gases pass through a discharge path 11a having an electrolytic cell edge cutting valve 9a, a first pipe 8a, and a detoxification tower inlet edge cutting valve 10a, and are led to the first detoxification tower 5a. Then, hydrogen fluoride is removed by the first detoxification tower 5a. The fluorine gas that has passed through the first detoxification tower 5a is guided to the outside of the fluorine gas generator 100 and stored in a storage tank or the like.

  On the other hand, in the cathode chamber 2, hydrogen gas containing hydrogen fluoride is generated, and the generated hydrogen gas is discharged from the hydrogen gas generation port 7b. These gases pass through a discharge passage 11b having an electrolytic cell edge cutting valve 9b, a second pipe 8b, and a detoxification tower inlet edge cutting valve 10b, and are led to the second detoxification tower 5b. And hydrogen fluoride is removed in the 2nd detoxification tower 5b. The hydrogen gas that has passed through the second detoxification tower 5 b is guided to the outside of the fluorine gas generator 100.

  Next, an operation of stopping the electrolysis and purging the hydrogen fluoride supply pipe 31 will be described. The hydrogen fluoride cylinder edge-cutting valve 256, the edge-cutting valve 257 and the edge-cutting valve 258 are closed, the edge-cutting valve 259 is opened, and hydrogen fluoride remaining in the hydrogen fluoride supply pipe 31 is discharged from a vent port (not shown). The inside of the hydrogen fluoride supply pipe 31 is exhausted. Then, the edge cutting valve 258 is opened, the edge cutting valve 259 is closed, and nitrogen gas is introduced into the purge gas supply pipe 253 from a nitrogen gas source (not shown). Nitrogen gas passes through the purge gas supply pipe 253 and flows to the hydrogen fluoride supply pipe 31. When the edge cut valve 259 is opened, the hydrogen fluoride gas remaining in the hydrogen fluoride supply pipe 31 is led to the vent pipe 254 by the nitrogen gas and released from the vent port (not shown). Thus, the hydrogen fluoride gas remaining in the hydrogen fluoride supply pipe 31 is discharged from the hydrogen fluoride supply pipe 31. The introduction of the nitrogen gas and the exhaust in the hydrogen fluoride supply pipe 31 are repeated, and the inside of the hydrogen fluoride supply pipe 31 is purged.

  At this time, the purge gas supply pipe 253, the vent pipe 254, the edge-cutting valve 258 and the edge-cutting valve 259 are heated by the line heater 232 above the boiling point of hydrogen fluoride (about 20 ° C. or higher). The remaining hydrogen fluoride passes through the purge gas supply pipe 253, the vent pipe 254, the edge cutting valve 258 and the edge cutting valve 259 without being liquefied, and is discharged from the discharge port.

  As described above, in the fluorine gas generator 200 of the present embodiment, the inside of the purge gas supply pipe 253, the vent pipe 254, the edge cutting valve 258, and the edge cutting valve 259 is heated to about 20 ° C. or more by the line heater 232. The liquefaction of the fluorine gas remaining inside the purge gas supply pipe 253, the vent pipe 254, the edge cutting valve 258 and the edge cutting valve 259 can be suppressed. As a result, even when nitrogen gas cooled from the inlet of the purge gas supply pipe 253 is introduced, the fluorine gas remaining in the pipes and valves as described above is not liquefied. Even when the outlet of the vent pipe 254 is rapidly cooled, the fluorine gas that has passed through the vent pipe 254 together with the nitrogen gas is not liquefied. Therefore, corrosion of the purge gas supply pipe 253 and the vent pipe 254 and damage to the edge cutting valve 258 and the edge cutting valve 259 can be reduced, and the fluorine gas generator 200 can be operated continuously for a long period of time.

  Further, since the line heater 232 is attached over the entire length of the hydrogen fluoride supply pipe 31, the purge gas supply pipe 253, and the vent pipe 254, the inner walls of the hydrogen fluoride supply pipe 31, the purge gas supply pipe 253, and the vent pipe 254 are provided. And the inside can be heated uniformly, and solidification and liquefaction of hydrogen fluoride due to the occurrence of partial temperature unevenness in the piping and insufficient temperature can be suppressed.

  Subsequently, modified examples in which various changes are made to the present embodiment will be described. 3 and 4 are schematic configuration diagrams of a fluorine gas generator according to a modification of the present invention. In addition, about the thing similar to 1st Embodiment and reference embodiment, it shows with the same code | symbol and abbreviate | omits description.

[First Modification]
In the fluorine gas generator 300 of the first modification shown in FIG. 3, the heater 350 is provided on the side surface of the cabinet 255 in the reference embodiment shown in FIG. The heater 350 is a hollow cylindrical heater that surrounds the side surface of the cabinet 255, and surrounds the entire side surface of the cabinet 255. The heater 350 heats the cabinet 255 from the outside, and makes the cabinet 255 a thermostat. Accordingly, the temperature inside the cabinet 255 is controlled to be equal to or higher than the boiling point of hydrogen fluoride (20 ° C. or higher) regardless of the temperature outside the cabinet 255. As the heater 350, a normal heater including a heating wire is used, but a line heater or the like that is directly wound around the side surface of the cabinet 255 may be used.

  In the fluorine gas generator 300 of the first modification, the same effects as those of the fluorine gas generator 100 according to the first embodiment and the fluorine gas generator 200 according to the reference embodiment can be obtained. Moreover, since the cabinet 255 is a thermostat by the heater 350, even if the environmental temperature of the installation place of the hydrogen fluoride supply apparatus 230 changes rapidly, the temperature inside the cabinet 255 is not affected. Therefore, the insides of the hydrogen fluoride supply pipe 31, purge gas supply pipe 253, vent pipe 254, edge cutting valve 257, edge cutting valve 258 and edge cutting valve 259 can always be set to the boiling point or higher (20 ° C. or higher). Since the hydrogen fluoride passing through the apparatus 230 is not solidified and liquefied, corrosion of equipment such as piping and valves of the hydrogen fluoride supply apparatus can be suppressed, and the life of these equipment can be extended. Moreover, since almost all the side surfaces in the hydrogen fluoride supply device 230 are heated by the heater 350, the inside of the hydrogen fluoride supply device 230 can be heated uniformly.

[Second Modification]
In the second modification, as shown in FIG. 4, in the first embodiment, the hydrogen fluoride supply device 230 used in the reference embodiment and the first modification is used instead of the hydrogen fluoride supply device 30. Yes. Moreover, the heater 350 similar to a 1st modification is provided in the side surface of the cabinet 255 of the hydrogen fluoride supply apparatus 230 in a reference embodiment and a 1st modification.

  In the fluorine gas generator 400 of the second modification, the same effect as that of the fluorine gas generator 100 of the first embodiment can be obtained. Further, like the fluorine gas generator 200 of the reference embodiment and the fluorine gas generator 300 of the first modified example, liquefaction of hydrogen fluoride in the hydrogen fluoride supply device 230 can be suppressed, so that the remaining hydrogen fluoride In addition, damage to the hydrogen fluoride supply pipe 31, the purge gas supply pipe 253, and the vent pipe 254, and damage to the edge cutting valve 257, the edge cutting valve 258, and the edge cutting valve 259 can be suppressed.

[Third Modification]
In the third modification, as shown in FIG. 5, in the first embodiment, a mass flow controller 501 is provided in the middle of the hydrogen fluoride supply pipe 31. Further, the hydrogen fluoride supply pipe 31 is connected to the purge gas supply pipe 502 at a position upstream of the mass flow controller 501. A line heater 510 is wound around the entire length of the hydrogen fluoride supply pipe 31 and the purge gas supply pipe 502. In this modification, nitrogen gas is used as a gas for purging the hydrogen fluoride supply pipe 31.

  The mass flow controller 501 measures the flow rate and flow rate of the hydrogen fluoride gas introduced from the inlet of the hydrogen fluoride supply pipe 31 and the nitrogen gas introduced from the purge gas supply pipe 502. Further, the flow rate and flow rate of hydrogen fluoride gas and nitrogen gas supplied to the electrolytic cell 3 are controlled. The mass flow controller 501 receives a command from the second liquid level detection sensor 20 and the pressure gauge 22 and controls the gas flow rate.

  When the liquid level of the electrolytic bath 4 in the cathode chamber 2 becomes higher than the liquid level of the electrolytic bath 4 in the anode chamber 1, the pressure gauge 21 detects a pressure higher than normal, and the second liquid level detection sensor 20. The liquid level is detected by the shortest sensor or the second shortest sensor. These results are transmitted to the mass flow controller 501, and the mass flow controller 501 reduces the supply amount of hydrogen fluoride and increases the supply amount of nitrogen gas so that the hydrogen fluoride supply pipe 31 does not become negative pressure. On the other hand, when the liquid level of the electrolytic bath 4 in the cathode chamber 2 is lower than the electrolytic bath 4 in the anode chamber 1, the pressure gauge 21 detects a pressure lower than normal, and the second liquid level detection sensor. 20 detects the height of the liquid level with the longest sensor or the second longest sensor. These results are transmitted to the mass flow controller 501, and the mass flow controller 501 increases the supply amount of hydrogen fluoride and decreases the flow rate of nitrogen gas. As described above, the flow rate and flow rate of the hydrogen fluoride gas and the nitrogen gas supplied to the electrolytic cell 3 are controlled according to the fluctuation of the liquid level of the electrolytic bath 4.

  One end of the purge gas supply pipe 502 is connected to a nitrogen gas supply source (not shown), and the other end is connected to the hydrogen fluoride supply pipe 31 via an edge cut valve 503. The edge cutting valve 503 is provided on the hydrogen fluoride supply pipe 31 and is closed when the supply of hydrogen fluoride is stopped.

  The nitrogen gas introduced from the purge gas supply pipe 502 indicates that the hydrogen fluoride supply pipe 31 becomes negative when the supply of hydrogen fluoride is stopped or the supply amount of hydrogen fluoride is reduced. Introduced to prevent. When the hydrogen fluoride supply pipe 31 has a negative pressure, the electrolytic bath flows back to the hydrogen fluoride supply pipe 31, and the backflowed electrolytic bath solidifies in the hydrogen fluoride supply pipe 31, thereby blocking the hydrogen fluoride supply pipe 31. Or the mass flow controller 501 and the edge cutting valve 503 are blocked or corroded. In order to prevent such blockage and damage of the piping and equipment, nitrogen gas is introduced to prevent the inside of the hydrogen fluoride supply pipe 31 from becoming a negative pressure.

  The line heater 510 is wound around the entire length of the hydrogen fluoride supply pipe 31 and the purge gas supply pipe 502, the mass flow controller 501, and the edge cut valves 503 and 504. As a result, the inner walls and the inside of the hydrogen fluoride supply pipe 31 and the purge gas supply pipe 502 are heated to a temperature equal to or higher than the boiling point of hydrogen fluoride. Similarly, the inside of the mass flow controller 501 and the edge cutting valves 503 and 504 are also heated to a temperature equal to or higher than the boiling point of hydrogen fluoride. As a result, the total length of the hydrogen fluoride supply pipe 31 and the purge gas supply pipe 502, the hydrogen fluoride existing in the mass flow controller 501 and the edge-cutting valves 503 and 504 are not liquefied, and these pipes and valves are formed of hydrogen fluoride. Corrosion does not occur. In the present embodiment, the line heater 510 wound around the hydrogen fluoride supply pipe 31 is wound up to the entrance of the electrolytic cell 3. Moreover, you may attach a heat insulating material with the line heater 510 around piping and a valve | bulb. As a result, a temperature above the boiling point of hydrogen fluoride (about 20 ° C. or higher) can be stably maintained for a long time.

  The hydrogen fluoride supply pipe 31 is a pipe that supplies hydrogen fluoride gas from a hydrogen fluoride supply source (not shown) to the electrolytic cell 3, but in this modification, when the supply of hydrogen fluoride gas is stopped, a purge is performed. The pipe (hydrogen fluoride supply pipe 31) from the connection position where the gas supply pipe 502 is connected to the electrolytic cell 3 also becomes the vent pipe 254 in the reference embodiment and the first and second modifications. When the supply of hydrogen fluoride gas to the electrolytic cell 3 is stopped and nitrogen gas is introduced from the purge gas supply pipe 502, the nitrogen gas is supplied to the hydrogen fluoride supply pipe 31 (hydrogen fluoride supply pipe 31 downstream from the valve 503). Flowing. The hydrogen fluoride gas remaining in the hydrogen fluoride supply pipe 31 (downstream from the valve 503) is sent into the electrolytic cell 3 by this nitrogen gas. In the hydrogen fluoride supply pipe 31, the hydrogen fluoride gas is replaced with nitrogen gas to be purified.

  In the fluorine gas generator 500 of the third modified example, the same effect as that of the fluorine gas generator 100 of the first embodiment can be obtained. Further, the entire length of the hydrogen fluoride supply pipe 31 and the purge gas supply pipe 502, the mass flow controller 501, the edge cut valve 503, and the inside of the edge cut valve 504 are heated by the line heater 510 to a temperature equal to or higher than the boiling point of hydrogen fluoride. Therefore, liquefaction of hydrogen fluoride remaining in these pipes and valves can be suppressed. Further, since the inside of the purge gas supply pipe 502 is heated, the heated nitrogen gas can be supplied to the hydrogen fluoride supply pipe 31. Thus, even when the cooled nitrogen gas is supplied from the inlet of the purge gas supply pipe 502, the hydrogen fluoride gas introduced from the hydrogen fluoride supply pipe 31 is not liquefied. The insides of the mass flow controller 501 and the hydrogen fluoride gas demarcation valve 503 are not corroded by fluorine gas, and the life of these devices can be extended.

  The hydrogen fluoride supply pipe 31 can be used as a vent pipe when not only supplying hydrogen fluoride from the hydrogen fluoride supply source to the electrolytic cell 3 but also stopping the supply of hydrogen fluoride gas to the electrolytic cell 3. Therefore, it is possible to purify the hydrogen fluoride supply pipe 31 while reducing the corrosion of the hydrogen fluoride supply pipe 31, the mass flow controller 501, and the hydrogen fluoride gas edge cutting valve 503 with a simple configuration without providing a vent pipe. it can.

  In both the above embodiment and the modification, the heating of the hydrogen fluoride supply pipe 31 is performed up to the entrance of the electrolytic cell 3, but the upper side (upstream) of the electrolytic bath 4 in the electrolytic cell 3. The hydrogen fluoride supply pipe 31 may be heated above the melting point of the molten salt in the electrolytic bath 4 by an in-bath pipe heating means (not shown). The temperature inside the hydrogen fluoride supply pipe 31 may be lower than the temperature of the molten salt above the liquid level of the electrolytic bath 4, and even slightly, the molten salt that has flowed back in the hydrogen fluoride supply pipe 31 is not enough. If the liquid flows back above the liquid level of the electrolytic bath 4, there is a risk of clogging due to solidification. It is also possible to prevent the occurrence of the above-mentioned blockage by providing an in-bath tube heating means and heating the upper part of the electrolytic bath 4 above the liquid surface to the melting point or higher of the molten salt.

  Next, a description will be given using an example.

Example 1
In the fluorine gas generator according to the present embodiment shown in FIG. 1, the fluorine gas generator without the pressure adjustment valve and the cooling fan was operated. Here, the first line heater and the second line heater were heated above the melting point of the electrolytic bath and at about 80 ° C. or lower. Moreover, the 1st piping and 2nd piping used the piping diameter of 9.525 * 10 < ^-3 > m.

(Comparative Example 1)
In the fluorine gas generator used in Example 1, the fluorine gas generator without the first line heater and the second line heater was operated. In addition, it drive | operated on the conditions similar to Example 1 except the conditions which have not attached the 1st line heater and the 2nd line heater. The results of Example 1 and Comparative Example 1 are shown in Table 1.

From Table 1, although Example 1 uses the pipe | tube with a pipe diameter smaller than the pipe | tube with a pipe diameter of 12.7 * 10 < ^-3 > m normally used, accumulated electric quantity is 72000 Ah or more. I was able to drive. As a result, it is possible to prevent the mist of the electrolytic bath from being solidified and clogged by the electrolytic cell edge cutting valve, the first piping, the second piping, and the detoxification tower inlet edge cutting valve, and to be able to operate the fluorine gas generator longer and continuously. I understood. On the other hand, in Comparative Example 1, since the mist of the electrolytic bath solidified and clogged when passing through the thawing edge cutting valve, the first piping, the second piping, and the detoxification tower inlet cutting valve, the accumulated amount of electricity was 35911 Ah and fluorine. The gas generator has stopped operating.

(Example 2)
In the fluorine gas generator used in Example 1, as shown in FIG. 1, a first pressure adjusting valve is provided in the middle of the outlet passage downstream of the first detoxification tower, and the outlet of the outlet passage downstream of the second elimination tower. A second pressure regulating valve was provided on the way to operate the fluorine gas generator. Here, both the positions where the first pressure adjustment valve and the second pressure adjustment valve were provided were about 35 ° C.

(Comparative Example 2)
In the fluorine gas generator used in Example 1, each of the first pipe and the second pipe to which the first line heater and the second line heater are attached between the electrolytic cell edge cutting valve and the detoxification tower inlet edge cutting valve, respectively. A pressure regulating valve was provided to operate the fluorine gas generator. Here, each position where the pressure adjusting valve was provided was about 70 ° C.

  In Example 2, it was found that the pressure regulating valve could be used for about 6 months or longer. On the other hand, in Comparative Example 2, the life of the pressure regulating valve is about 3 months, and the reactivity of fluorine gas and hydrogen fluoride gas increases at a high temperature of about 70 ° C., and the resin used for the seal portion of the pressure regulating valve. Was found to have been eroded.

(Example 3)
In the fluorine gas generator used in Example 2, the fluorine gas generator was operated using the fluorine gas generator according to the present embodiment shown in FIG. 1 in which a cooling fan was provided around the electrolytic cell. Here, the electrolytic bath heating heater and the cooling fan were operated to adjust the electrolytic bath temperature to 85 to 87 ° C.

  In Example 3, it turned out that scattering of an electrolytic bath can be suppressed. In addition, the temperature of the electrolytic cell itself can be adjusted by the electrolytic bath warming heater and the cooling fan, and the life can be extended by suppressing deterioration and corrosion of the gas seal part of the electrolytic cell (not shown) and the attached valve. all right.

Example 4
Using the fluorine gas generator according to the reference embodiment shown in FIG. 2, a cycle purge of the hydrogen fluoride supply device was performed. Here, the inside of the hydrogen fluoride supply pipe 31, the purge gas supply pipe 253, the vent pipe 254, the hydrogen fluoride cylinder edge cutting valve 256, and the edge cutting valves 257, 258, and 259 was heated to 20 ° C. or more by the line heater 232. The cycle purge means that the edge cutting valve 256 and the edge cutting valve 257 are closed, the edge cutting valve 259 is opened, the hydrogen fluoride supply pipe 31 is exhausted, nitrogen gas is introduced from the purge gas supply pipe 253, and then the edge cutting valve 259 is opened. The exhaust gas in the hydrogen fluoride supply pipe 31 and the introduction of nitrogen gas into the hydrogen fluoride supply pipe 31 are repeated so that the inside of the hydrogen fluoride supply pipe 31 is exhausted again. Is a method of purging. Then, the number of times of maintenance until the gas vent edge cutting valve leaks was measured.

(Example 5)
Using the fluorine gas generator according to the first modification shown in FIG. 3, the cycle purge of the hydrogen fluoride supply device and the gas flow in the cabinet were performed. As in Example 4, the insides of the hydrogen fluoride supply pipe 31, purge gas supply pipe 253, vent pipe 254, hydrogen fluoride cylinder edge cutting valve 256 and edge cutting valves 257, 258, and 259 were raised to 20 ° C. or higher by a line heater. Warmed up. The cabinet 255 was heated to a constant temperature layer by heating with a heater 350 provided around the cabinet 255, and the temperature inside the cabinet 255 was always set to 20 ° C. or higher. In the same manner as in Example 4, the number of maintenance until the edge cutting valve 259 provided in the middle of the vent pipe 254 leaks was measured.

(Comparative Example 3)
Using the fluorine gas generator according to the reference embodiment shown in FIG. 2, the cycle purge of the hydrogen fluoride supply device and the gas flow in the cabinet were performed. Here, heating by a line heater was not performed. The environmental temperature of the cabinet was 18 degrees. And the frequency | count of the maintenance until the edge cutting valve 259 provided in the middle of the vent pipe 254 leaks was measured. These results are shown in Table 2.

  From Table 2, it can be seen that Example 4 in which the inside of the piping and the valve was set to a temperature equal to or higher than the boiling point of hydrogen fluoride by the line heater has a larger number of maintenance than the Comparative Example 3, and the valve is not easily damaged. Further, in Example 5, since the inside of the cabinet is maintained at a temperature equal to or higher than the boiling point of hydrogen fluoride, liquefaction of hydrogen fluoride can be further prevented, the life of the valve is further prolonged, and the number of maintenance is further increased. doing. In contrast, in Comparative Example 3, it can be seen that the maintenance frequency is small, hydrogen fluoride remaining in the piping and the edge-cutting valve 259 is liquefied, and the edge-cutting valve 259 is corroded by hydrogen fluoride. From these results, by using a heater around the line heater or cabinet, liquefaction of hydrogen fluoride can be prevented, damage to the valve can be reduced, and the life of the valve can be extended.

(Example 6)
The operation of the mass flow controller 501 was examined using the fluorine gas generator according to the third modification shown in FIG. In addition, a line heater 510 and a heat insulating material are attached to the hydrogen fluoride supply pipe 31, the purge gas supply pipe 502, the mass flow controller 501, and the edge cut valves 503 and 504, and the inside is higher than the boiling point of hydrogen fluoride (about 20 ° C. or higher). The temperature was adjusted. The operation of the fluorine gas generator is performed by closing the edge-cutting valve 504, opening the edge-cutting valve 503, introducing hydrogen fluoride into the hydrogen fluoride supply pipe 31, and then closing the edge-cutting valve 503 and opening the edge-cutting valve 504. By introducing the gas, the position downstream of the edge cutting valve 503 of the hydrogen fluoride supply pipe 31 is purged, and then the edge cutting valve 504 is closed again and the gas edge cutting valve 503 is opened again to supply hydrogen fluoride with hydrogen fluoride. The introduction into the tube 31 was repeated. Then, the operation of the mass flow controller 501 when switching between introduction of hydrogen fluoride gas and nitrogen gas was examined.

(Comparative Example 4)
The fluorine gas generator according to the third modification shown in FIG. 5 was operated without operating the line heater 510. In addition, like Example 6, the fluorine gas generator unit was operated, and the operation of the mass flow controller 501 was examined.

  In Comparative Example 4, the mass flow controller was operating in an unstable manner when switching the gas to be introduced. This is presumably because the hydrogen fluoride remaining in the hydrogen fluoride supply pipe and the mass flow controller was liquefied and the mass flow controller was corroded by this hydrogen fluoride. Moreover, it is considered that the corrosion of the mass flow controller is promoted by the liquefaction of hydrogen fluoride. On the other hand, in Example 6, the unstable operation | movement like the comparative example 4 was not seen, but it operate | moved stably. As a result, the hydrogen fluoride gas existing in the hydrogen fluoride supply pipe, the mass flow controller, and the edge cutting valve was not liquefied by the line heater and the heat insulating material, so that damage to the mass flow controller due to hydrogen fluoride could be suppressed. Recognize.

  As mentioned above, although the fluorine gas generator of embodiment of this invention was demonstrated, this invention is not limited to the above-mentioned embodiment, As long as it describes in the claim, various changes are possible. . For example, in the present embodiment shown in FIG. 1, instead of using a line heater as the tank heating means, a sheet heater that covers the entire electrolytic cell edge cutting valve, first piping, second piping, and abatement tower inlet edge cutting valve is used. Alternatively, a heater may be arranged around the entire electrolytic cell edge cutting valve, the first piping, the second piping, and the detoxification tower inlet edge cutting valve.

  In the present embodiment, the electrolytic bath warming heater provided so as to surround the side surface of the electrolytic cell is used as the cell heating means. Instead, a line heater may be used to wrap around the electrolytic cell. . This also provides the same effect.

  Moreover, in this embodiment, instead of air cooling means such as a fan used as a tank cooling means, a water cooling means in which a metal tube is wound around an electrolytic cell may be used.

  Further, in the present embodiment and this modification, the line heater 232 wound around the hydrogen fluoride supply pipe 31 is wound up to the inlet of the electrolytic cell 3 downstream of the hydrogen fluoride supply pipe 31. It is also possible to wrap up to just before the hydrogen fluoride supply pipe 31 contacts the electrolytic bath 4.

  In the embodiment and the modification described above, the valve may be a manual valve, an automatic valve, or a combination thereof. Even if any of these valves is used, the same effect as in the embodiment and the modification described above can be obtained. can get.

DESCRIPTION OF SYMBOLS 1 Anode chamber 2 Cathode chamber 3 Electrolysis tank 4 Electrolytic bath 5a 1st detoxification tower 5b 2nd detoxification tower 6a 1st pressure regulation valve 6b 2nd pressure regulation valve 7a Fluorine gas generation port 7b Hydrogen gas generation port 8a 1st piping 8b Second piping 9a, 9b Electrolyzer edge cutting valve 10a, 10b Detox tower inlet edge cutting valve 11a, 11b Discharge path 12a First line heater 12b Second line heater 13 Electrolytic bath warming heater 14 Electrolytic bath warming heater protective cover 15 Cooling fan 16 Bulkhead 17 Anode 18 Cathode 19 First liquid level detection sensor
20 Second liquid level detection sensor 21, 22 Pressure gauges 23a, 23b Lead-out path 30, 230 Hydrogen fluoride generator 31 Hydrogen fluoride supply pipe 232 Line heater 251 Hydrogen fluoride cylinder 253 Purge gas supply pipe 254 Vent pipe
257, 258, 259 Edge cut valve 350 Heater 100, 200, 300, 400, 500 Fluorine gas generator

Claims (10)

A fluorine gas generator comprising an electrolytic cell containing an electrolytic bath made of a molten salt containing hydrogen fluoride,
A discharge passage for passing a fluorine-containing gas generated by electrolyzing the electrolytic bath;
A detoxification tower for removing impurities from the fluorine-containing gas,
The discharge path is provided to communicate the gas phase portion of the electrolytic cell and the detoxification tower;
A fluorine gas generator having a first heating means for heating a gas passing through the discharge passage inner wall and / or the discharge passage to a temperature equal to or higher than a melting point of the electrolytic bath. Including the electrolytic bath electrolytic bath is housed comprising a molten salt containing hydrogen fluoride, Oite the discharge passage through which the fluorine-containing gas and the electrolytic bath is generated by electrolysis, as a mist in the fluorine-containing gas fluorine gas generator, wherein a solid of melting salt contained is adapted to be suppressed. It has a pressure regulating valve provided downstream from the detoxification tower,
The pressure regulating valve has a seal portion;
The fluorine gas generator according to claim 1, wherein a fluorine resin is used for the seal portion. The first heating means is a first heating body provided in contact with an outer wall of the discharge path;
The said 1st heating body is provided over the full length of the said discharge path, The fluorine gas generator of Claim 1 or 3 characterized by the above-mentioned. And a hydrogen fluoride supply device for supplying hydrogen fluoride to the electrolytic bath,
The hydrogen fluoride supply device is
A hydrogen fluoride source,
A hydrogen fluoride supply path for supplying hydrogen fluoride from the hydrogen fluoride supply source to the electrolytic cell;
A purge gas supply path for introducing an inert gas into the hydrogen fluoride supply path;
An inert gas discharge path for discharging hydrogen fluoride from the hydrogen fluoride supply path by the introduced inert gas;
5. The second heating means for heating the gas passing through the purge gas supply path and the inert gas discharge path to a temperature equal to or higher than the boiling point of hydrogen fluoride. The fluorine gas generator according to any one of the above. The second heating means is a second heating body provided in contact with outer walls of the purge gas supply path and the inert gas discharge path;
The fluorine gas generator according to claim 5, wherein the second heating body is provided over the entire length of the purge gas supply path and the inert gas discharge path. And a hydrogen fluoride supply device for supplying hydrogen fluoride to the electrolytic bath,
The hydrogen fluoride supply device is
The hydrogen fluoride supply source, the hydrogen fluoride supply path, the purge gas supply path, and the inert gas discharge path, and at least a hydrogen fluoride supply source and the hydrogen fluoride supply path 5. The fluorine gas generator according to claim 1, further comprising third heating means for heating all of the purge gas supply path. The third heating means is a third heating body provided in contact with outer walls of the hydrogen fluoride supply path and the purge gas supply path;
The fluorine gas generator according to claim 7, wherein the third heating body is provided over the entire length of the hydrogen fluoride supply path and the purge gas supply path. In the hydrogen fluoride supply path, a part from the middle of the hydrogen fluoride supply path to the electrolytic cell serves as the inert gas discharge path,
6. The inert gas discharge path, wherein the hydrogen fluoride can be replaced with an inert gas introduced from the hydrogen fluoride supply path when the supply of hydrogen fluoride is stopped. The fluorine gas generator of any one of -8.   Furthermore, it has a tank heating means for heating the said electrolytic bath, and a tank cooling means for cooling the said electrolytic bath, The any one of Claims 1 to 3-9 characterized by the above-mentioned. The fluorine gas generator as described.

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