KR20220164348A - A sulphur hexafluoride(SF6) refinement system and refineing method using the same - Google Patents

Abstract

The present invention relates to a sulfur hexafluoride (SF_6) refinement device and a sulfur hexafluoride (SF_6) refinement method and to a sulfur hexafluoride (SF_6) refinement device which is configured to refine sulfur hexafluoride (SF_6) that can be reused after refinement. The sulfur hexafluoride (SF_6) refinement device comprises: a supply unit formed to have a supply container for supplying a sulfur hexafluoride (SF_6) mixture; a recovery unit having a vacuum pump and a compressor and configured to transport the sulfur hexafluoride (SF_6) mixture; a pretreatment unit configured to remove solid and liquid impurities contained in the sulfur hexafluoride mixture; a separation unit configured to refine the sulfur hexafluoride (SF_6) mixture from which the impurities are removed; a storage unit configured to store sulfur hexafluoride (SF_6) purified from the separation unit; and a charging unit formed to fill a charging container with the purified sulfur hexafluoride (SF_6). The separation unit comprises: a first separation unit configured to refine the sulfur hexafluoride (SF_6) mixture from which the impurities are removed; a second separation unit configured to refine a first gas exhausted from the first separation unit; and A third separation unit configured to refine a second gas exhausted from the second separation unit.

Description

Sulfur hexafluoride (SF6) refinement system and refinement method using the same}

The present invention relates to a sulfur hexafluoride (SF ₆ , hereinafter referred to as “sulfur hexafluoride” or sulfur hexafluoride gas”) purification apparatus and method, and specifically, from a mixture containing sulfur hexafluoride (SF ₆ ) It relates to a purification device for purifying sulfur fluoride and a method for purifying sulfur hexafluoride from a mixture containing the sulfur hexafluoride.

Sulfur hexafluoride gas (SF ₆ ) has been used at high pressure since the early 1960s due to its high dielectric strength (about 3 times that of air), high thermal insulating ability (about 10 times that of air) and high heat transfer performance (about 2 times that of air). and medium voltage switchgear, GIS (Gas Insulated Switchgear), loop main circuit, auto circuit breaker, transformer, cable, etc. have been successfully used in electrical equipment.

In addition, the sulfur hexafluoride gas is used not only in the electric industry, but also in aluminum production, magnesium smelting, semiconductor production, flat screen production, nuclear fuel cycle, noise-proof windows, tires, high-performance radar, tracking gas for climate measurement, power plant pipes, and military applications. Sulfur hexafluoride gas with a high concentration of 90% to 100% is used in the electrical industry, and sulfur hexafluoride gas with a low concentration of about 1% is used in fields other than the electrical industry. are doing

On the other hand, in Korea, about 80% of the total sulfur hexafluoride gas consumption is used in the electrical industry. For example, GIS (Gas Insulated Switchgear), medium voltage gas switchgear, high voltage gas switchgear, high voltage gas insulated wire, gas insulated voltage SF6 is used as an insulator in power facilities such as transformers, and it is stored and recovered through a closed cycle.

When an arc is generated due to fault repair or an unexpected internal arc failure in a power facility using sulfur hexafluoride gas as an insulator, ions, radicals, and Various by-products such as neutral molecules are continuously generated. Most of these by-products recombine to form sulfur hexafluoride gas, while some combine with other materials used in equipment manufacturing, such as oxygen and water.

In this case, impurities such as HF, SO ₂ , SOF ₂ , SOF ₄ , SO ₂ F ₂ , SF ₄ , CF ₄ , in addition to sulfur hexafluoride gas may be included in the closed cycle. In addition, when sulfur hexafluoride gas is charged or discharged in a closed cycle for maintenance of power facilities, nitrogen, oxygen, water, etc. generated by the inflow of air and water vapor may become major impurities, and other handling and Air and oil components generated during the repair process may also become impurities.

Sulfur hexafluoride gas has a very high global warming potential (GWP) of 23,900 times that of carbon dioxide (CO ₂ ), and remains in the atmosphere for a long period of 3,200 _years without decomposing in the atmosphere. Recycling rather than discharging is environmentally and economically important. Therefore, it is necessary to prevent emissions in the atmosphere and manage them in an environmentally compatible manner in a series of processes such as development, design, production, service, maintenance and recovery.

To this end, various technologies, including pressure swing adsorption (PSA), membrane separation, deep-cold liquefaction/solidification using a freezer or refrigerant, distillation, and gas hydrate, are currently being used for polluted sulfur hexafluoride gas generated at industrial sites. being improved or developed.

The adsorption method is a type of gas separation method and is a technology using the fact that adsorption characteristics are different depending on the material. The adsorption method uses an adsorbent such as activated carbon or zeolite to separate materials by giving a pressure change (PSA) or temperature change (TSA, Temperature Swing Adsorption). There is a problem that the purity of the large and purified sulfur hexafluoride gas is low, and there is a limit to the enlargement and concentration of the facility.

The membrane separation method using the membrane is a gas separation technology using a difference in gas permeability, and hollow fiber membranes based on polysulfone and polyimide are mainly used. The membrane separation method is useful for concentrating low-concentration sulfur hexafluoride gas, but in order to commercialize high-concentration sulfur hexafluoride gas separation and purification technology using a separation membrane, high-selectivity membrane material, hollow fiber membrane processing technology, and large-area module development and process development for each application field is required.

Sulfur hexafluoride gas separation/purification technology using the deep cooling method (or liquefaction/solidification method) is a technology to separate and refine the sulfur hexafluoride gas to be separated into a liquid or solid state by using a refrigerator or liquid nitrogen as a refrigerant to be. Compared to the adsorption method and the membrane separation method, the time required for the process is short and the purity can be increased, but energy is required for liquefaction or solidification, and the entire process is operated under harsh conditions of low temperature and high pressure. The disadvantage is that ancillary devices are required, and thus a high cost of manufacturing the device is required.

The distillation method is a type of deep cooling method (liquefaction method), which is a method of liquefying hexafluoride gas at a low temperature and then distilling it using a distillation column. The distillation method is again divided into a continuous distillation method in which distillation is performed continuously and a batch distillation method in which batch distillation is performed. In order to obtain ultra-high purity, the batch distillation method is more advantageous.

The distillation method has the advantage of obtaining ultra-high purity hexafluoride gas that can be used in the semiconductor industry, but it requires a lot of equipment manufacturing cost, including a cryogenic distillation column, etc., and it is not easy to move the device due to the nature of the distillation column.

In addition, it is possible to separate impurities having a similar boiling point to the hexafluoride gas, but in this case, the number of stages of the distillation column increases and the height of the distillation column increases, so there is a disadvantage in that equipment and operating costs are high.

The technology using gas hydrate is a technology of refining sulfur hexafluoride gas by making it into anti-hexafluoride-hydrate. Anti-hexafluoride gas can form anti-hexafluoride-hydrate under relatively mild conditions compared to other gases. It is a technique based on points.

The gas hydrate is a solid compound made by forming a physical bond between gas molecules and water molecules in a low temperature/high pressure state. It has the advantage of requiring less energy than the liquefaction method, the solidification method, and the distillation method. On the other hand, since the formation rate of sulfur hexafluoride-hydrate is slow, additives are required to improve the selectivity of sulfur hexafluoride, and a large amount of water is used, a water removal process is required when separating sulfur hexafluoride from sulfur hexafluoride-hydrate. The downside is that it requires extra.

Considering the characteristics of each technology, it can be said that the sulfur hexafluoride separation and purification technology using the deep cooling method is the most advantageous in terms of concentration, scale, and economic feasibility of the purification target for the recovery and recycling of sulfur hexafluoride gas used in the electrical industry. can

Therefore, in the present invention, when purifying sulfur hexafluoride gas using the deep cooling method, it is intended to propose a sulfur hexafluoride purification apparatus and method that can improve the efficiency of energy required and at the same time improve the recovery rate and purification purity.

An object of the present invention is to provide a purification apparatus and a purification method for purifying sulfur hexafluoride from a mixture containing sulfur hexafluoride.

In addition, an object of the present invention is to increase the purification recovery rate of the sulfur hexafluoride and to increase the purity of the purification.

In addition, it aims to reduce the operating cost by reducing the energy consumed by minimizing the amount of gas processed under harsh conditions (low temperature, high pressure).

However, these tasks are illustrative, and the scope of the present invention is not limited thereby.

One object of the present invention for achieving the above object is to provide a supply container for supplying a sulfur hexafluoride (SF ₆ ) mixture in a sulfur hexafluoride purification apparatus for refining sulfur hexafluoride (SF ₆ ) that can be reused after purification. A supply unit formed to be provided, a recovery unit equipped with a vacuum pump and a compressor and transporting the sulfur hexafluoride mixture, a pretreatment unit for removing solid and liquid impurities contained in the sulfur hexafluoride mixture, and sulfur hexafluoride from which the impurities are removed. It includes a separation unit for purifying the mixture, a storage unit for storing the purified sulfur hexafluoride from the separation unit, and a charging unit configured to charge the purified sulfur hexafluoride into a charging container, wherein the separation unit removes the impurities. A first separator for purifying the sulfur hexafluoride mixture, a second separator for purifying the first gas exhausted from the first separator, and a third separator for purifying the second gas exhausted from the second separator It provides a sulfur hexafluoride purification device that is to do.

According to one embodiment of the present invention, the first separation unit has a first packing material and a first heat exchange unit therein, and a first connection unit connected to the storage unit and the first separation unit and the second The second connection part may include a second connection part connecting the separation part, and the second connection part may include a first discharge part diverging from the second connection part and discharging gas to the outside.

According to one embodiment of the present invention, the second separation unit has a second packing material and a second heat exchange unit therein, and a third connection unit connected to the storage unit and the second separation unit and the third The fourth connection part may include a fourth connection part connecting the separator, and the fourth connection part may include a second discharge part diverging from the fourth connection part and discharging gas to the outside.

According to one embodiment of the present invention, the second separator may include a first transfer unit for re-transferring the purified sulfur hexafluoride to the first separator.

According to one embodiment of the present invention, the first separator and the second separator each include a purity measuring device, wherein the purity measuring device includes an infrared sensor for measuring infrared absorption according to the medium, and an infrared sensor for measuring infrared absorption according to the density of the wholesale quality. A sound velocity sensor that measures the speed of sound passing through the medium, a thermal conductivity sensor that detects the change in thermal conductivity according to the purity of the medium, and a capillary tube that detects the modulation of the regular vibration applied to the microtube according to the medium inside the microtube. tube) may include a vibration density sensor.

According to an embodiment of the present invention, the third separation unit has a separation membrane module therein, and a second transfer unit for re-transferring sulfur hexafluoride purified in the third separation unit and a second transfer unit for discharging the impurity gas to the outside. 3 may include an outlet.

According to one embodiment of the present invention, the sulfur hexafluoride purification apparatus may include a system control unit for automatic and manual control and a meter for measuring operating factors including temperature, pressure, flow rate, level, and the like.

According to another object of the present invention, a supply step of supplying a sulfur hexafluoride (SF ₆ ) mixture from a supply unit to a pretreatment unit, a pretreatment step of removing solid and liquid impurities contained in the sulfur hexafluoride mixture, and removing the impurities A purification step of purifying the purified sulfur hexafluoride mixture, a storage step of storing the purified sulfur hexafluoride mixture, and a charging step of filling the stored sulfur hexafluoride mixture into a filling container, wherein the purification step is performed by removing the impurities. A first purification step of purifying the sulfur hexafluoride mixture, a second purification step of purifying the sulfur hexafluoride purified from the first purification step, and a third purification step of purifying the sulfur hexafluoride purified from the second purification step. It provides a method for purifying sulfur hexafluoride, which includes.

According to one embodiment of the present invention, the supplying step may be to supply the sulfur hexafluoride mixture contained in the supply container of the supply unit to the pretreatment unit by forming a pressure difference in the recovery unit.

According to one embodiment of the present invention, the first purification step is a first cooling step of cooling the sulfur hexafluoride mixture from which the solid and liquid impurities are removed to separate the first sulfur hexafluoride and the first impurity gas, the A first discharge step of discharging a first impurity gas, a step of heating the first sulfur hexafluoride to form vaporized first purified sulfur hexafluoride, and transferring the first purified sulfur hexafluoride to a storage unit and a second separation unit. It may include the step of doing.

According to one embodiment of the present invention, the first cooling step may be cooling by passing through the first filler roll and performing a first heat exchange.

According to one embodiment of the present invention, the first discharging step may be to control the discharging of the first impurity gas to be stopped when a set pressure is reached at a predetermined discharging temperature determined according to the concentration of the first sulfur hexafluoride. .

According to one embodiment of the present invention, the step of transferring the first purified sulfur hexafluoride to the storage unit and the second separation unit measures the purity of the first purified sulfur hexafluoride in real time, and the first purified sulfur hexafluoride according to the measured purity. It may be to control the flow of sulfur hexafluoride.

According to one embodiment of the present invention, when the purity of the first purified sulfur hexafluoride measured in real time is 99.9% or more, it is transferred to the storage unit, and when the purity of the first purified sulfur hexafluoride is less than 99.9%, transferred to the second separation unit it could be

According to one embodiment of the present invention, the second purification step is a second cooling step of cooling the first purified sulfur hexafluoride to separate it into a second sulfur hexafluoride and a second impurity gas, discharging the second impurity gas It may include a second discharge step, forming vaporized second purified sulfur hexafluoride by heating the second sulfur hexafluoride, and transferring the second purified sulfur hexafluoride to a storage unit and a third separation unit. there is.

According to one embodiment of the present invention, the second cooling step may be cooling by passing through the second filler and exchanging the second heat.

According to one embodiment of the present invention, the second discharging step may be to control the discharging of the second impurity gas to be stopped when a set pressure is reached at a predetermined discharging temperature determined according to the concentration of the second sulfur hexafluoride. .

According to one embodiment of the present invention, the step of transferring the second purified sulfur hexafluoride to the storage unit and the third separation unit measures the purity of the second purified sulfur hexafluoride in real time, and the second purification according to the measured purity. It may be to control the flow of sulfur hexafluoride.

According to one embodiment of the present invention, if the purity of the second purified sulfur hexafluoride measured in real time is 99.9% or more, it is transferred to the storage unit, and if the purity of the second purified sulfur hexafluoride is less than 99.9%, it is transferred to the third separation unit it could be

According to an embodiment of the present invention, the third purification step is the step of separating the second purified sulfur hexafluoride into a third purified sulfur hexafluoride and a third impurity gas by passing through a separation membrane module, and discharging the third impurity gas. and a step of retransferring the third purified sulfur hexafluoride to the second separator.

The present invention has the effect of providing a sulfur hexafluoride gas purification device and purification method.

In addition, there is an effect of increasing the purification purity of the sulfur hexafluoride gas while increasing the purification recovery rate.

In addition, there is an effect of reducing operating expenses by reducing energy consumption by minimizing the amount of gas processed under harsh conditions (low temperature, high pressure).

In addition, it is possible to efficiently recover the low-concentration hexafluoride purification target gas, which has the effect of widening the range of purification targets.

A further scope of the applicability of the present invention will become apparent from the detailed description that follows. However, since various changes and modifications within the spirit and scope of the present invention can be clearly understood by those skilled in the art, it should be understood that the detailed description and specific examples such as preferred embodiments of the present invention are given by way of example only.

1 is a schematic conceptual diagram of a sulfur hexafluoride purification system according to an embodiment of the present invention.
Figure 2 is a vapor pressure curve according to the temperature of sulfur hexafluoride according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. These examples are only illustratively indicated to explain the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. will be.

In addition, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art to which the present invention belongs, and in case of conflict, this specification including definitions of will take precedence.

In order to clearly explain the proposed invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification. And when it is said that a certain component "includes", it means that it may further include other components, not excluding other components unless otherwise stated. In addition, a “unit” described in the specification means one unit or block that performs a specific function.

In each step, the identification code (first, second, etc.) is used for convenience of description, and the identification code does not describe the order of each step, and each step does not clearly describe a specific order in context. It may be performed differently from the order specified above.

1 is a schematic conceptual diagram of a sulfur hexafluoride purification system according to an embodiment of the present invention.

Referring to FIG. 1, the sulfur hexafluoride purification apparatus 100 of the present invention includes a supply unit 110, a recovery unit 120, a pre-processing unit 130, a separating unit 140, a storage unit 150, and a charging unit 160. ).

The supply unit 110 is characterized in that it is formed to have a supply container for supplying a sulfur hexafluoride (SF ₆ ) mixture.

The sulfur hexafluoride mixture is obtained by recovering sulfur hexafluoride used by charging in electrical equipment such as GIS (Gas Insulated Switchgear), annular circuit, auto circuit breaker, transformer, cable, etc., in addition to the sulfur hexafluoride, decomposition products and work Characterized in that it is a mixture containing air due to leakage.

In this case, the decomposition product may include SO ₂ , SOF ₂ , HF, CF ₄ , and the like, and the air due to the leakage may include N ₂ , O ₂ , moisture, oil, and the like. In addition, the supply container may be a generally cylindrical gas container. A typical cylindrical gas container has a valve at the top so that gas can be charged or discharged.

The recovery unit 120 transfers the sulfur hexafluoride mixture, and is characterized in that it extends from the supply unit 110. In detail, the recovery unit 120 includes a vacuum pump and a compressor, and the vacuum pump and compressor can be used as power for transferring the sulfur hexafluoride mixture. That is, the sulfur hexafluoride mixture can be smoothly transferred by using the vacuum pump and the compressor of the recovery unit 120 .

The pretreatment unit 130 is characterized in that it is formed to remove solid and liquid impurities contained in the sulfur hexafluoride mixture. In detail, the pretreatment unit 130 includes an impurity removal device, and the impurity removal device is composed of a pretreatment scrubber, activated alumina, activated charcoal, and a molecular sieve in order characterized by being

The separation unit 140 purifies the sulfur hexafluoride mixture from which impurities are removed, and the separation unit 141 includes a first separation unit 141, a second separation unit 142, and a second separation unit 143. ).

The first separator 141 is characterized in that the first gas is formed by purifying the sulfur hexafluoride mixture from which the impurities are removed using a deep cooling method. In detail, the first separation unit 141 has a first packing material and a first heat exchange unit therein, and includes a first connection unit 1 connected to the storage unit 150 and the first separation unit 141 . A second connection part 2 connecting the part 141 and the second separation part 142 is included.

At this time, it is preferable that the second connection part 2 includes a first discharge part 3 branched from the second connection part 2 and discharging gas to the outside.

In addition, the second connection part 2 may discharge impurity gases having a lower density than liquid or solid sulfur hexafluoride or saturated sulfur hexafluoride separated in the first separation part 141 .

In addition, since the first filler is made of a material that facilitates heat transfer, energy efficiency can be improved by the first filler. For example, the first filler preferably includes a material having high thermal conductivity, and may include an alloy including aluminum and copper.

The second separator 142 is characterized in that the second gas is formed by purifying the exhausted first gas purified by the first separator 141 using a deep cooling method.

In detail, the second separator 412 includes a third connection part 4 having a second packing material and a second heat exchange part therein and connected to the storage part 150, The second separation part 142 includes a fourth connection part 5 connecting the second separation part 142 and the third separation part 143 .

At this time, the fourth connection part 5 is branched from the fourth connection part 5 to the second discharge part 6 and the first separation part 141 for discharging gas to the outside, and partially purified sulfur hexafluoride is measured. It includes a first transfer unit 7 for transferring, and the fourth connection unit 5 is preferably disposed above the second separation unit 142 .

As the fourth connection part 5 is disposed above the second separation part 142, the density is lower than that of liquid or solid sulfur hexafluoride or saturated sulfur hexafluoride separated from the second separation part 142. Impurity gases may be released.

In addition, the second filler is a material that facilitates heat transfer, and energy efficiency can be improved by the second filler, and the second filler may be the same material as the first filler.

On the other hand, the first separation unit 141 and the second separation unit 142 are characterized in that they include a purity measuring device. Specifically, the purity measuring device includes the first separating part 141 and the second separating part 142, respectively, and the purity measuring device includes the second connecting part 2 and the fourth connecting part 5 It is preferable to be placed in

At this time, the purity measuring device measures the purity of the purified sulfur hexafluoride, an infrared sensor for measuring infrared absorption according to the medium, a sound velocity sensor for measuring the speed of sound passing through the medium according to the density of the medium, and the purity of the medium It is characterized in that it includes a thermal conductivity sensor for detecting a change in thermal conductivity according to the capillary tube and a capillary tube vibration density sensor for detecting a modulation of regular vibration applied to the capillary tube according to the medium inside the capillary tube.

The third separation unit 143 purifies the second gas purified and exhausted by the second separation unit 142 using a membrane separation method, and has a separation membrane module inside the third separation unit 143, , It is characterized in that it includes a second transfer unit 9 for re-transferring the sulfur hexafluoride purified in the third separation unit 143 and a third discharge unit 8 for discharging the impurity gas to the outside.

At this time, the second gas has sulfur hexafluoride removed through two steps, and the concentration of sulfur hexafluoride is very low compared to the sulfur hexafluoride mixture and the first gas from which impurities are removed. Therefore, the purification efficiency can be improved by using the separation membrane method instead of the deep cooling method.

The storage unit 150 stores the purified sulfur hexafluoride from the separation unit 140, and extends from the separation unit 140, and the storage unit 150 is located at the bottom of the separation unit 140. It is characterized by being placed in. At this time, it is preferable that the storage unit 150 is formed to alleviate the pressure change formed during the purification of sulfur hexafluoride in the separation unit 140.

The charging unit 160 is formed to charge the purified sulfur hexafluoride stored in the storage unit 150, and the charging unit 160 further includes a charging container and a vacuum exhaust unit.

On the other hand, the sulfur hexafluoride purification apparatus 100 according to the present invention is characterized in that it includes an instrument for measuring operating factors including temperature, pressure, flow rate, level, etc. and a system control unit (not shown) for automatic and manual control. do.

That is, it is possible to control (control) the entire process of sulfur hexafluoride purification through the meter and the system controller for automatic and manual control.

Hereinafter, the sulfur hexafluoride purification method using the sulfur hexafluoride purification apparatus 100 will be described in detail.

Sulfur hexafluoride purification method includes a supply step of supplying a sulfur hexafluoride (SF ₆ ) mixture from a supply unit to a pretreatment unit, a pretreatment step of removing solid and liquid impurities contained in the sulfur hexafluoride mixture, and hexafluoride from which the impurities are removed. It includes a purification step of purifying the sulfur mixture, a storage step of storing the purified sulfur hexafluoride, and a charging step of filling the stored sulfur hexafluoride into a filling container.

The supplying step is characterized in that the sulfur hexafluoride mixture contained in the supply container of the supply unit 110 is supplied to the pretreatment unit 130 by forming a pressure difference in the recovery unit 120.

The pretreatment step is characterized in that the sulfur hexafluoride mixture supplied from the supply unit 110 is passed through the pretreatment unit 130 to pre-treat the sulfur hexafluoride mixture from which solid and liquid impurities are removed.

In detail, the sulfur hexafluoride mixture is pretreated by passing through the impurity removal device of the pretreatment unit 130, pretreatment scrubber, activated alumina, activated charcoal and molecular sieve It can be preprocessed by passing through in order. At this time, as the pretreatment step proceeds, acidic impurities may be removed.

The purification step includes a first purification step of purifying the sulfur hexafluoride mixture from which the impurities are removed, a second purification step of purifying the sulfur hexafluoride purified from the first purification step, and a hexafluoride purified from the second purification step. It is characterized in that it comprises a third purification step of purifying sulfur.

It is characterized in that it is made in the first separation unit 141 by purifying 99.9% or more high-purity sulfur hexafluoride through the first purification step.

The first purification step includes a first cooling step of cooling the sulfur hexafluoride mixture from which impurities in the solid and liquid phases are removed and separating the mixture into first sulfur hexafluoride and a first impurity gas, and a first step of discharging the first impurity gas. Discharge step, heating the first purified sulfur hexafluoride to form vaporized first purified sulfur hexafluoride and transferring the first purified sulfur hexafluoride to the storage unit 150 and the second separation unit 142 includes

The first cooling step is cooling by passing through a first filler material and performing a first heat exchange. In order to cool the sulfur hexafluoride mixture from which the impurities are removed, a refrigerant is supplied to the first heat exchange unit, and the supplied refrigerant Pure sulfur hexafluoride in the sulfur hexafluoride mixture from which the impurities are removed may be cooled.

Specifically, the first cooling step is preferably performed at a predetermined pressure determined according to the concentration of sulfur hexafluoride at -10 ° C to -40 ° C.

For example, when the discharge temperature is -40 ° C or less and the concentration of sulfur hexafluoride is less than 40%, the predetermined pressure is preferably 13 times or more than the vapor pressure of sulfur hexafluoride. In addition, when the discharge temperature is -20 ° C or less and the concentration of sulfur hexafluoride is 40% or more, the predetermined pressure is preferably performed at 4.3 times or more of the sulfur hexafluoride vapor pressure. In addition, when the discharge temperature is -10 ° C or less and the concentration of sulfur hexafluoride is 60% or more, the predetermined pressure is preferably performed at more than twice the vapor pressure of sulfur hexafluoride. In addition, when the discharge temperature is -10 ° C or less and the concentration of sulfur hexafluoride is 80% or more, the predetermined pressure is preferably performed at 1.5 times or more than the vapor pressure of sulfur hexafluoride. In addition, when the discharge temperature is -10 ° C or less and the concentration of sulfur hexafluoride is 80% or more, the predetermined pressure is preferably performed at a sulfur hexafluoride vapor pressure or higher.

The first discharge step is to discharge the first impurity gas having a lower density than the first sulfur hexafluoride (liquid phase or solid phase) or the first sulfur hexafluoride in a saturated state to the outside through the first discharge unit 3, It is characterized in that when the set pressure is reached at a predetermined discharge temperature determined according to the concentration of the first sulfur hexafluoride, the discharge of the first impurity gas is stopped.

Specifically, the sulfur hexafluoride mixture from which the impurities are removed coexists with gaseous impurities and saturated first sulfur hexafluoride, and since the density of the first sulfur hexafluoride is higher than that of air, which is the main impurity, the first sulfur hexafluoride mixture has a high density. Sulfur fluoride sinks to the lower part of the first separator 141 . Accordingly, the first impurity gas having a lower density than that of sulfur hexafluoride may be discharged to the outside through the first discharge unit 3 .

In the step of transferring the first purified sulfur hexafluoride to the storage unit 150 and the second separation unit 142, the purity of the first purified sulfur hexafluoride is measured in real time, and the first purified sulfur hexafluoride is measured according to the measured purity. It is characterized by controlling the flow of sulfur fluoride.

Specifically, the first sulfur hexafluoride from which the first impurity gas has been removed is heated and vaporized, and the flow of the first purified sulfur hexafluoride is controlled according to the purity of the vaporized first sulfur hexafluoride. In order to vaporize sulfur, it is preferable to perform heat exchange formed by supplying heat to the first heat exchange unit.

For example, if the purity of the first purified sulfur hexafluoride measured in real time is 99.9% or more, it is transferred to the storage unit 150, and if the purity of the first purified sulfur hexafluoride is less than 99.9%, the second separation unit 142 ) is preferred.

Meanwhile, the refrigerant is liquid nitrogen, and the fruit may be formed of nitrogen gas or a gas containing sulfur hexafluoride. Furthermore, the fruit may be supplied to the first heat exchange unit through a heater, blower or pump.

In addition, it can be performed using a heating device to heat and vaporize the first sulfur hexafluoride, and the heating device can be formed as a hot wire. The heating wire may generate heat by converting electrical energy into thermal energy.

The second purification step is to re-recover and purify the first purified sulfur hexafluoride having a purity of less than 99.9% purified through the first purification step, and is characterized in that it is performed in the second separation unit 142.

The second purification step includes a second cooling step of cooling the first purified sulfur hexafluoride to separate it into a second sulfur hexafluoride and a second impurity gas, a second discharge step of discharging the second impurity gas, and the second meat. Heating the sulfur fluoride to form vaporized second purified sulfur hexafluoride and transferring the second purified sulfur hexafluoride to the storage unit 150 and the third separation unit 143.

The second cooling step is cooling by passing through the second filler and performing second heat exchange. In order to cool the sulfur hexafluoride mixture from which the impurities are removed, a refrigerant is supplied to the second heat exchange unit, and the supplied refrigerant Pure sulfur hexafluoride in the sulfur hexafluoride mixture from which the impurities are removed may be cooled.

At this time, the refrigerant supplied to the second heat exchange unit is preferably the same as the refrigerant supplied to the first heat exchange unit.

Specifically, the second cooling step is preferably performed at a lower temperature and higher pressure than the first cooling step. As the second cooling step is performed at a lower temperature and higher front power than the first cooling step, the recovery rate of sulfur hexafluoride can be improved and the recovery speed can be increased.

The second discharge step is to discharge the second impurity gas having a lower density than the second sulfur hexafluoride (liquid phase or solid phase) or the second sulfur hexafluoride in a saturated state to the outside through the second discharge unit 6, It is characterized in that when the set pressure is reached at a predetermined discharge temperature determined according to the concentration of the second sulfur hexafluoride, the discharge of the second impurity gas is stopped.

Specifically, as the first purified sulfur hexafluoride formed by purifying the sulfur hexafluoride mixture is cooled, it is separated into a second sulfur hexafluoride and a second impurity gas, and the second sulfur hexafluoride having a high density is a second sulfur hexafluoride gas. It sinks to the bottom of the separator 142. Accordingly, the second impurity gas having a density lower than that of the second sulfur hexafluoride may be discharged to the outside through the second discharge unit 6 .

In the step of transferring the second purified sulfur hexafluoride to the storage unit 150 and the third separation unit 142, the purity of the second purified sulfur hexafluoride is measured in real time, and the second purified sulfur hexafluoride is measured according to the measured purity. It is characterized by controlling the flow of sulfur fluoride.

Specifically, by heating and vaporizing the second sulfur hexafluoride from which the second impurity gas has been removed, and controlling the flow of the second purified sulfur hexafluoride according to the purity of the vaporized second sulfur hexafluoride, the second sulfur hexafluoride In order to vaporize sulfur, it is preferable to perform heat exchange formed by supplying heat to the second heat exchange unit.

For example, when the purity of the second purified sulfur hexafluoride measured in real time is 99.9% or more, it is transferred to the storage unit 150, and when the purity of the second purified sulfur hexafluoride is less than 99.9%, the third separator (143 ) is preferred.

In other words, if the exhaust gas of the second separation unit 142 measured in real time is 99.9% or more, it is preferably transferred to the storage unit 150, and if it is less than 99.9%, it is transferred to the third separation unit 143.

The third purification step is to recover and purify the second purified sulfur hexafluoride having a purity of less than 99.9% purified through the second purification step, and is characterized in that it is performed in the third separation unit 143.

Specifically, the third purification step is a step of separating the second purified sulfur hexafluoride into a third purified sulfur hexafluoride and a third impurity gas by passing through a separation membrane module, and a third discharge step of discharging the third impurity gas. and retransferring the third purified sulfur hexafluoride to a second separator.

At this time, since the second purified sulfur hexafluoride purified in the third purification step has a very low concentration of sulfur hexafluoride, it is preferable to purify it using a separation membrane module rather than using a deep cooling method. For example, if the concentration of the second purified sulfur hexafluoride is less than 40%, if the purification is performed using the deep cooling method, it must be performed under very harsh conditions (-40 ° C or lower, high pressure), which increases energy consumption and reduces purification efficiency will do Accordingly, purification efficiency can be improved by increasing the concentration of sulfur hexafluoride using a separation membrane module and retransferring it to the second separator 142 .

In the storage step, sulfur hexafluoride purified through the first to third purification steps is stored in the storage unit 150, and the storage step is performed simultaneously while the purification step is performed. desirable.

At this time, the purified sulfur hexafluoride stored in the storage unit 150 through the purification step includes first purified sulfur hexafluoride and second purified sulfur hexafluoride, and the purified sulfur hexafluoride has a purity of 99.9% or more. desirable.

The charging step is characterized in that the purified sulfur hexafluoride stored in the storage unit 150 is charged into the charging unit 160. Specifically, it is characterized in that the environment inside the charging container of the charging unit 160 is formed in a vacuum state using a vacuum exhaust device and the purified sulfur hexafluoride is charged. At this time, the purified sulfur hexafluoride charged in the charging unit 160 can be reused as high-quality gas.

On the other hand, the sulfur hexafluoride purification method of the present invention can be performed in an automatic mode, a step-by-step automatic mode, or a manual mode.

In the automatic mode, the supplying step to the charging step may be continuously operated according to a predetermined logic. The operation of all stages may be performed only when a predetermined starting condition for each stage is satisfied.

In the step-by-step automatic mode, the supply step to the charging step may be operated independently when the charging step within the supply step meets a preset starting condition.

In the manual mode, the supplying step or the charging step may be operated by a user's manipulation regardless of preset conditions.

At this time, it is preferable to control the automatic mode and the step-by-step automatic mode through the controller.

Hereinafter, Examples and Comparative Examples will be described in detail. However, the following Examples, Experimental Examples and Comparative Examples are merely illustrative of the present invention, and the present invention is not limited by the following Examples, Experimental Examples and Comparative Examples.

Examples and Comparative Examples

comparative example

Suppose that sulfur hexafluoride (SF ₆ ) is separated from 100L of mixed gas to be purified (SF6 concentration before purification: 40, 60, 80, 98 vol%) in a refinery equipped with only the primary separation unit under specific temperature and pressure conditions It is a value mathematically calculated for the concentration of sulfur hexafluoride before and after purification, the volume and concentration of sulfur hexafluoride and the concentration of sulfur hexafluoride exhausted after purification in the primary separation unit, and the recovery rate of hexafluoride after final separation.

_The vapor pressure input value _{of sulfur hexafluoride} for each operating temperature is the same as in FIG.

In this case, the concentration of gas exhausted after purification in the separation unit can be calculated through Equation 1, and the volume of gas exhausted after purification in the separation unit can be calculated through Equation 2.

Calculation 1

C _vent : SF ₆ concentration in exhaust gas

P _v (t): SF ₆ vapor pressure at operating temperature (t) (see FIG. 2)

P _op : operating pressure

Calculation 2

V _vent : Exhaust gas volume

V _vent (SF ₆ ): volume of SF ₆ in exhaust gas

V _vent (non-SF ₆ ): volume of gas other than SF ₆ in exhaust gas

V ₀ : volume of processing gas

C ₀ : Concentration of SF ₆ in processing gas

C _vent : concentration of SF ₆ in exhaust gas

In addition, the recovery rate of sulfur hexafluoride purified and recovered through the separation unit can be calculated through the following formula 3.

Comparative Examples 1 to 4.

Assuming that SF6 is separated from 100L of the mixed gas to be purified in a refinery equipped with only the primary separation unit under conditions of temperature -10°C and pressure of 37 bar, which are commercial conditions, SF6 concentration before and after purification, in the primary separation unit Table 1 shows the mathematically calculated values of the volume of exhausted gas after purification, the concentration of SF6, and the recovery rate of SF6 after final separation.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 1st Separation Temperature (℃) -10 -10 -10 -10 pressure (bar) 37 37 37 37 Processing gas volume (L, @1bar) 100 100 100 100 SF ₆ concentration
(vol %) before purification 40 60 80 98 after purification ≥99.9 ≥99.9 ≥99.9 ≥99.9 exhaust 26 26 26 26 Exhaust gas volume (L, @1bar) 81 54 27 2.7 Recovery rate of SF ₆ after primary separation (%) 48 77 91 99

Referring to Table 1, in the case of a sulfur hexafluoride mixed gas having a purity of less than 80%, the recovery rate is 90% or less. In addition, a relatively high temperature (-10 ° C) and a relatively high pressure (37 bar) are operating conditions that aim for a fast purification rate, which requires some sacrifice of recovery rate and cannot effectively exclude impurities having a boiling point range similar to sulfur hexafluoride. can In addition, since the entire amount of the gas to be refined must be maintained at a high pressure, energy consumption is high.

Comparative Examples 5 to 8.

Sulfur hexafluoride concentration before and after purification, primary separation It is a value mathematically calculated for the volume of gas exhausted after purification in the unit, the concentration of sulfur hexafluoride, and the recovery rate of sulfur hexafluoride after final separation. The results for this are shown in Table 2.

division Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 1st Separation Temperature (℃) -50 -50 -50 -50 pressure (bar) 2.7 2.7 2.7 2.7 Processing gas volume (L, @1bar) 100 100 100 100 SF ₆ concentration
(vol %) before purification 80 90 95 98 after purification (unrecoverable) ≥99.9 ≥99.9 ≥99.9 exhaust 88 88 26 Exhaust gas volume (L, @1bar) 36 16 2.7 Recovery rate of SF ₆ after primary separation (%) 62 85 99

Referring to Table 2, in the case of sulfur hexafluoride mixed gas having a purity of less than 90%, recovery is not possible, and even at 90% purity, the recovery rate is less than 20%, so only very high purity gas can be purified. In addition, since the entire amount of the gas to be refined must be maintained at a relatively low temperature, energy consumption is high.

Example

Sulfur hexafluoride concentration before and after the 1st, 2nd, and 3rd purification, assuming that sulfur hexafluoride is separated from 100L of the mixed gas to be purified under specific temperature and pressure conditions in a refinery equipped with all of the 1st, 2nd, and 3rd separation units , 1st, 2nd, and 3rd separation units are mathematically calculated values of the volume of gas exhausted after purification, the concentration of SF6, and the recovery rate of sulfur hexafluoride after final separation.

At this time, it is assumed that the tertiary separation unit uses a membrane module, and the recovery rate of the membrane module is assumed to be 90%. It is known that the recovery rate of such a separation membrane is 90% or more in the case of a separation membrane made of polyimide or carbon molecular sieve under the condition that the concentration of sulfur hexafluoride is 5% or more.

Examples 1 to 4.

It was assumed that the first and second temperatures were fixed at -10 ° C, the first operating pressure was 15 bar, and the second operating pressure was 45 bar to separate sulfur hexafluoride, and the results are shown in Table 3 .

division Example 1 Example 2 Example 3 Example 4 1st Separation Temperature (℃) -10 -10 -10 -10 pressure (bar) 15 15 15 15 Processing gas volume (L,@1bar) 100 100 100 100 SF ₆ concentration
(vol %) before purification 40 60 80 98 after purification (collect
not allowed) (collect
not allowed) ≥99.9 ≥99.9 exhaust 63.9 63.9 Exhaust gas volume (L, @1bar) 55 5.5 Recovery rate of SF ₆ after primary separation (%) 56 96 2nd Separation Temperature (℃) (corresponding
doesn't exist) (corresponding
doesn't exist) -10 -10 pressure (bar) 45 45 Processing gas volume (L,@1bar) 55 5.5 SF ₆ concentration
(vol %) before purification 63.9 63.9 after purification ≥99.9 ≥99.9 exhaust 21 21 Exhaust gas volume (L,@1bar) 25 2.5 Recovery rate of SF ₆ after 1st + 2nd separation (%) 93 99 tertiary separation
(Assuming 90% membrane separation recovery rate) Processing gas volume (L,@1bar) (corresponding
doesn't exist) (corresponding
doesn't exist) 25 2.5 SF ₆ concentration
(vol%) before purification 21 21 after purification ≥40 ≥40 exhaust 2.1 2.1 Exhaust gas volume (L,@1bar) 20 2.0 Recovery rate of SF ₆ after 1+2+3 separation (%) 99 100

Referring to Table 3, in the primary refinery, operation is performed under relatively mild conditions (high temperature, low pressure) to increase energy efficiency and obtain high purity sulfur hexafluoride.

In the secondary refinery, the recovery rate of sulfur hexafluoride can be increased by operating under high-pressure conditions, and the volume of the processed gas can be reduced by more than 50% to increase energy efficiency. However, as in Example 1 and Example 2, when the concentration of sulfur hexafluoride is 80% or less, it is impossible to recover sulfur hexafluoride under the primary purification conditions, so the operation method should be adjusted according to the concentration of the target to be purified. The results for this are disclosed in Table 3.

Examples 5 to 8.

It was assumed that the first and second temperatures were fixed at -40 ° C, the first operating pressure was 15 bar, and the second operating pressure was 45 bar to separate sulfur hexafluoride, and the results are shown in Table 4. .

division Example 5 Example 6 Example 7 Example 8 1st Separation Temperature (℃) -40 -40 -40 -40 pressure (bar) 15 15 15 15 SF ₆ concentration
(vol%) before purification 40 60 80 98 after purification ≥99.9 ≥99.9 ≥99.9 ≥99.9 exhaust 23 23 23 23 Processing gas volume (L, @1bar) 100 100 100 100 Exhaust gas volume (L, @1bar) 78 52 26 2.6 Recovery rate of SF ₆ after primary separation (%) 55 80 92 99 2nd Separation Temperature (℃) -40 -40 -40 -40 pressure (bar) 45 45 45 45 SF ₆ concentration
(vol %) before purification 23 23 23 23 after purification ≥99.9 ≥99.9 ≥99.9 ≥99.9 exhaust 7.8 7.8 7.8 7.8 Processing gas volume (L, @1bar) 78 52 26 2.6 Exhaust gas volume (L, @1bar) 65 43 22 2.2 Recovery rate of SF ₆ after 1st + 2nd separation (%) 87 94 98 99.8 tertiary separation
(Assuming 90% membrane separation recovery rate) SF ₆ concentration
(vol%) before purification 7.8 7.8 7.8 7.8 after purification ≥40 ≥40 ≥40 ≥40 exhaust 0.8 0.8 0.8 0.8 Processing gas volume (L, @1bar) 65 43 22 2.2 Exhaust gas volume (L, @1bar) 60 40 20 2.0 Recovery rate of SF ₆ after 1+2+3 separation (%) 99 99 99.8 100

Referring to Table 4, compared to Examples 1 to 4, since the primary purification is performed under low temperature conditions, it is possible to efficiently recover the gas to be refined even under conditions where the concentration of the target gas is very low. Therefore, it can be seen that the operating conditions can be adjusted in a wide range according to the concentration of the gas to be refined.

Examples 9 to 12.

The results are shown in Table 5 assuming that sulfur hexafluoride is separated by optimizing the operating conditions (temperature, pressure) of the first and second refineries according to the concentration of the gas to be refined.

division Example 9 Example 10 Example 11 Example 12 1st Separation Temperature (℃) -20 -10 -10 -10 pressure (bar) 30 20 15 10 SF ₆ concentration
(vol %) before purification 40 60 80 98 after purification ≥99.9 ≥99.9 ≥99.9 ≥99.9 exhaust 23 48 64 96 Processing gas volume (L, @1bar) 100 100 100 100 Exhaust gas volume (L, @1bar) 78 77 55 48 Recovery rate of SF ₆ after primary separation (%) 55 38 56 53 2nd Separation Temperature (℃) -40 -30 -20 -10 pressure (bar) 45 30 30 30 SF ₆ concentration
(vol%) before purification 23 48 64 96 after purification ≥99.9 ≥99.9 ≥99.9 ≥99.9 exhaust 7.8 17 23 32 Processing gas volume (L, @1bar) 78 77 55 48 Exhaust gas volume (L, @1bar) 65 48 26 2.9 Recovery rate of SF ₆ after 1st + 2nd separation (%) 87 87 92 99 tertiary separation
(Assuming 90% membrane separation recovery rate) SF ₆ concentration
(vol %) before purification 7.8 17 23 (Unnecessary) after purification ≥40 ≥40 ≥40 exhaust 0.8 1.7 2.3 Processing gas volume (L, @1bar) 65 48 26 Exhaust gas volume (L, @1bar) 60 40 20 Recovery rate of SF ₆ after 1+2+3 separation (%) 99 99 99

Referring to Table 5, when the concentration of the gas to be refined is 60% or less, the first purification must be performed at a relatively low temperature and high pressure, but even at this time, the pressure is reduced with relatively less energy and time consumed than cooling by internal heat transfer. Increasing it may be more efficient.

Therefore, the example was presented with the minimum cooling temperature and pressure conditions that can purify sulfur hexafluoride. From these examples, it can be seen that the present invention can treat a gas to be refined in a wide concentration range, and can simultaneously increase energy efficiency and recovery rate.

In this specification, only a few examples of various embodiments performed by the present inventors are described, but the technical spirit of the present invention is not limited or limited thereto, and can be modified and implemented in various ways by those skilled in the art, of course.

Claims (20)

In the sulfur hexafluoride purification apparatus for purifying sulfur hexafluoride (SF ₆ ) that can be reused after purification,
Sulfur hexafluoride (SF ₆ ) A supply unit formed to have a supply container for supplying a mixture;
a recovery unit having a vacuum pump and a compressor and transporting the sulfur hexafluoride mixture;
A pretreatment unit for removing solid and liquid impurities contained in the sulfur hexafluoride mixture;
Separation unit for purifying the sulfur hexafluoride mixture from which the impurities are removed;
a storage unit for storing sulfur hexafluoride purified from the separation unit; and
To include; a filling part formed to fill the purified sulfur hexafluoride into a filling container,
the separation unit,
A first separator for purifying the sulfur hexafluoride mixture from which the impurities are removed;
a second separator purifying the first gas exhausted from the first separator;
A third separator for purifying the second gas exhausted from the second separator;
Sulfur hexafluoride refinery. According to claim 1,
The first separation unit has a first packing material and a first heat exchange unit therein,
A first connection part connected to the storage part and a second connection part connecting the first separation part and the second separation part,
Wherein the second connection part includes a first discharge part branched from the second connection part and discharging gas to the outside,
Sulfur hexafluoride refinery. According to claim 1,
The second separation unit has a second packing material and a second heat exchange unit therein,
A third connection part connected to the storage part and a fourth connection part connecting the second separation part and the third separation part,
The fourth connection part includes a second discharge part branched from the fourth connection part and discharging gas to the outside,
Sulfur hexafluoride refinery. According to claim 3,
Wherein the second separation unit comprises a first transfer unit for re-transferring the purified sulfur hexafluoride to the first separation unit,
Sulfur hexafluoride refinery. According to claim 1,
The first separation unit and the second separation unit each include a purity measuring device,
The purity measuring device includes an infrared sensor for measuring infrared absorption according to the medium, a sound velocity sensor for measuring the speed of sound passing through the medium according to the density of the medium, a thermal conductivity sensor for detecting a change in thermal conductivity according to the purity of the medium, and a microtube inside. To include a capillary tube vibration density sensor that detects the modulation of regular vibration applied to the microtube according to the medium of the
Sulfur hexafluoride refinery. According to claim 1,
The third separation unit has a separation membrane module therein,
A second transfer unit for retransferring the sulfur hexafluoride purified in the third separator and a third discharge unit for discharging the impurity gas to the outside,
Sulfur hexafluoride refinery. According to claim 1,
The sulfur hexafluoride purification device includes an instrument for measuring operating factors including temperature, pressure, flow rate, level, etc., and a system control unit for automatic and manual control,
Sulfur hexafluoride refinery. A supply step of supplying a sulfur hexafluoride (SF ₆ ) mixture from the supply unit to the pre-processing unit;
A pretreatment step of removing solid and liquid impurities contained in the sulfur hexafluoride mixture;
A purification step of purifying the sulfur hexafluoride mixture from which the impurities are removed;
A storage step of storing the purified sulfur hexafluoride; and
A charging step of charging the stored sulfur hexafluoride into a charging container; comprising,
The purification step is
A first purification step of purifying the sulfur hexafluoride mixture from which the impurities are removed;
A second purification step of purifying sulfur hexafluoride purified from the first purification step;
A third purification step of purifying sulfur hexafluoride purified from the second purification step;
A purification method for sulfur hexafluoride. According to claim 8,
The supplying step is to supply the sulfur hexafluoride mixture contained in the supply container of the supply unit to the pretreatment unit by forming a pressure difference in the recovery unit,
A purification method for sulfur hexafluoride. According to claim 8,
The first purification step may include a first cooling step of cooling the sulfur hexafluoride mixture from which the solid and liquid phase impurities are removed and separating into first sulfur hexafluoride and a first impurity gas;
a first discharge step of discharging the first impurity gas;
Heating the first sulfur hexafluoride to form vaporized first purified sulfur hexafluoride; and
Transferring the first purified sulfur hexafluoride to a storage unit and a second separation unit; comprising
A purification method for sulfur hexafluoride. According to claim 10,
The first cooling step is to pass through the first filler roll and cool by first heat exchange.
A purification method for sulfur hexafluoride. According to claim 10,
The first discharge step is to control the discharge of the first impurity gas to be stopped when a set pressure is reached at a predetermined discharge temperature determined according to the concentration of the first sulfur hexafluoride.
A purification method for sulfur hexafluoride. According to claim 10,
In the step of transferring the first purified sulfur hexafluoride to the storage unit and the second separation unit, the purity of the first purified sulfur hexafluoride is measured in real time,
Controlling the flow of the first purified sulfur hexafluoride according to the measured purity,
A purification method for sulfur hexafluoride. According to claim 13,
When the purity of the first purified sulfur hexafluoride measured in real time is 99.9% or more, it is transferred to the storage unit,
When the purity of the first purified sulfur hexafluoride is less than 99.9%, it is transferred to the second separator,
The purification method of six northern flowers. According to claim 8,
The second purification step may include a second cooling step of cooling the first purified sulfur hexafluoride and separating it into second sulfur hexafluoride and a second impurity gas;
a second discharge step of discharging the second impurity gas;
Heating the second sulfur hexafluoride to form vaporized second refined sulfur hexafluoride; and
Transferring the second purified sulfur hexafluoride to a storage unit and a third separation unit; comprising
A purification method for sulfur hexafluoride. According to claim 15,
The second cooling step is cooling by passing through the second filler and exchanging the second heat,
A purification method for sulfur hexafluoride. According to claim 15,
The second discharge step is to control the discharge of the second impurity gas to stop when a set pressure is reached at a predetermined discharge temperature determined according to the concentration of the second sulfur hexafluoride.
A purification method for sulfur hexafluoride. According to claim 15,
In the step of transferring the second purified sulfur hexafluoride to the storage unit and the third separation unit, the purity of the second purified sulfur hexafluoride is measured in real time,
Controlling the flow of the second purified sulfur hexafluoride according to the measured purity,
A purification method for sulfur hexafluoride. According to claim 18,
When the purity of the second purified sulfur hexafluoride measured in real time is 99.9% or more, it is transferred to the storage unit,
When the purity of the second purified sulfur hexafluoride is less than 99.9%, it is transferred to the third separator,
The purification method of six northern flowers. According to claim 8,
The third purification step includes separating the second purified sulfur hexafluoride into third purified sulfur hexafluoride and a third impurity gas by passing the second purified sulfur hexafluoride through a separation membrane module;
a third discharge step of discharging the third impurity gas; and
Re-transferring the third purified sulfur hexafluoride to the second separator;
A purification method for sulfur hexafluoride.

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