JP6082361B2 - Gas supply method - Google Patents

Description

  The present invention relates to a gas supply method, and more particularly, to a gas supply method for supplying a fluorine mixed gas from a container filled with high pressure to a consumption facility through a decompression unit.

  Conventionally, nitrogen trifluoride gas has been used as a cleaning gas for semiconductor manufacturing equipment. However, nitrogen trifluoride gas has a high global warming potential of 17200, and in consideration of environmental problems, fluorine with a global warming potential of 0 is used. The amount of gas used has been increasing in recent years. In addition, a resin material having good shape following property is used as a sealing material in order to prevent leakage at the connecting portion of each device and piping in the cleaning gas supply facility. However, when high-pressure gas is supplied from a high-pressure filled container, the resin material may be thermally deformed, melted, or burned out due to heat generated by adiabatic compression and shock waves when the gas is introduced into the pipe.

  Therefore, in order to prevent the resin material from being thermally deformed, melted or burned out, a gas supply method has been proposed in which a high-pressure filled container is supplied to a consumption facility via a shock wave attenuation mechanism (for example, Patent Document 1, Patent Document 1). 2).

JP 2012-154429 A JP 2012-167813 A

  In the methods described in Patent Documents 1 and 2, it is necessary to bother to provide a shock wave attenuating mechanism, which not only complicates the apparatus configuration in the supply facility, but also may not ensure a necessary and sufficient flow rate to the consumption facility.

  Therefore, the present invention is capable of reliably preventing the resin material in the constituent equipment from being thermally deformed, melted or burned out without having a complicated apparatus configuration, and capable of supplying a sufficient flow rate to the consumption facility. It aims to provide a method.

In order to achieve the above object, a gas supply method of the present invention is a gas supply method for supplying a consumption facility after depressurizing a fluorine mixed gas filled in a container with high pressure through a decompression means, the container of the container Filling and filling the pipe from the valve to the decompression means with an inert gas having a pressure higher than the supply pressure to the consuming equipment and lower than the filling pressure of the container, After that , the supply of the fluorine mixed gas to the consuming equipment is started in a state where the inert gas is sealed in the pipe .

Further, it is preferable to perform a purge process step of replacing the inside of the pipe with an inert gas before the filling and sealing step, and the pressure of the inert gas in the filling and sealing step is 5 to 10 times the supply pressure. Preferably there is.

  Furthermore, it is suitable for applying the gas supply method of the present invention that the sheet material of the decompression means is an ethylene trifluoride resin and the consuming equipment is a semiconductor manufacturing apparatus.

  According to the present invention, the inert gas having a pressure higher than the supply pressure to the consumption facility and lower than the filling pressure of the container is filled in the pipe from the container valve to the pressure reducing means. Thus, since adiabatic compression and shock waves in the pipe during gas supply can be mitigated, it is possible to reliably prevent thermal deformation, melting or burning of the resin material. Further, by performing a purge process step of replacing the inside of the pipe with an inert gas before the filling and enclosing step, it is possible to prevent impurities from being mixed. In addition, by making the pressure of the inert gas in the filling and enclosing process 5 to 10 times the supply pressure, excessive inert gas is not used and the economy is high.

It is explanatory drawing which shows one example of the supply equipment to which the gas supply method of this invention is applied.

  FIG. 1 is an explanatory diagram showing an example of a supply facility to which the gas supply method of the present invention is applied. The supply facility 1 decompresses the fluorine mixed gas filled in the high-pressure gas container 10 with a pressure regulator 11 as decompression means, and supplies it to a consumption facility (not shown) such as a semiconductor manufacturing apparatus.

  In the piping from the container valve 10a to the pressure regulator 11 of the high-pressure gas container 10, the first three-way valve 12, the first pressure gauge 13, the first filter 14, the second three-way valve 15, and the first gate valve are sequentially arranged from the upstream side. 16 is provided.

  In addition, the pipe from the pressure regulator 11 to the consuming equipment has a second pressure gauge 17, a third three-way valve 18, a second filter 19, a second gate valve 20, a flow meter 21, and a third partition in order from the upstream side. A valve 22 is provided.

  Each port of the first three-way valve 12 is connected to the high-pressure gas container 10, an inert gas supply source (not shown), and the first filter 14.

  The two ports of the second three-way valve 15 are connected to the first filter 14 and the first gate valve 16, and the remaining one port is connected to the exhaust pipe 23. Two ports of the third three-way valve 18 are connected to the pressure regulator 11 and the second filter 19, and the remaining one port is connected to the exhaust pipe 24.

  Next, the gas supply method of the present invention will be described. First, the container valve 10a and the pressure regulator 11 of the high-pressure gas container 10 are closed, the first gate valve 16 is opened, and the piping from the high-pressure gas container 10 to the pressure regulator 10 is in a communicating state.

  Next, the port connected to the inert gas supply source of the first three-way valve 12 is opened, and after introducing the inert gas into the pipe, the port connected to the inert gas supply source is closed again. The port connected to the exhaust pipe 23 of the second three-way valve 15 is opened to discharge and exhaust the gas in the pipe, and then the port connected to the exhaust pipe 23 is closed again. By repeatedly introducing and evacuating the inert gas a plurality of times, the air existing in the pipe is replaced with the inert gas (purge process step of the present invention).

  After the purge process step is completed, the port connected to the inert gas supply source of the first three-way valve 12 is opened, and the inert gas is filled into the pipe. When the pressure of the filled inert gas becomes a predetermined pressure that is higher than the supply pressure to the consumption equipment and lower than the filling pressure of the high-pressure gas container 10 by the pressure gauge 13, the pressure is supplied to the inert gas supply source. The connecting port is closed and the inert gas is sealed in the pipe (filling and sealing step of the present invention).

  Thereafter, the second gate valve 20 and the third gate valve 22 are opened, the container valve of the high-pressure gas container 10 is opened, the fluorine mixed gas is introduced into the piping, and the pressure regulator 11 is operated to be opened. , Start gas supply to consumption equipment.

  Hereinafter, the effect of the present invention will be described by comparing an example and a comparative example.

  A high-pressure gas container 10 filled with a mixed gas obtained by diluting fluorine gas with nitrogen to a volume ratio of 20% was prepared at 10 MPa, and nitrogen gas was used as the inert gas. Further, the pressure on the secondary side of the pressure regulator 11 was set to 0.2 MPa, and PCTFE (ethylene trifluoride resin) was used as the sheet material of the pressure regulator 11. The filling pressure of nitrogen gas in the filling and sealing step after the purge treatment step was set to 2 MPa.

  Gas supply was started by the method as described above, the amount of gas passed was measured with the flow meter 21, and the sheet leak inspection of the pressure regulator 11 was performed with nitrogen gas for every 500 L passed gas. No seat leak was observed even when it was used.

<Comparative example>
On the other hand, as a comparative example, the purge process was performed in the same manner as in the example, but the gas supply was started without filling the pipe with nitrogen gas. As in the example, the amount of gas flow was measured with the flow meter 21 and the sheet leak inspection of the pressure regulator 11 was performed with nitrogen gas for every 500 L of gas passed. Was confirmed.

  In the comparative example, it was assumed that the sheet leak was confirmed that the PCTFE of the sheet of the pressure regulator 11 was thermally damaged. On the other hand, it was confirmed that the effects of adiabatic compression and shock waves can be sufficiently mitigated by filling the pipe with nitrogen gas as in the examples.

  In addition to the nitrogen gas, argon, helium, neon, xenon, krypton, and other gases can be used as the inert gas. However, it is preferable from the economical aspect to use inexpensive and commercially available nitrogen.

  Further, the pressure in the filling and sealing step is appropriately determined from the filling pressure of the high-pressure gas container 10, the supply pressure pressure to the consumption equipment (secondary pressure of the pressure regulator 11), the heat resistant temperature of the sheet material, the length and diameter of the pipe, and the like. Can be determined. It can be said that the higher the pressure in the filling and sealing process, the more adiabatic compression and shock wave will be mitigated. It is preferably 5 to 10 times the pressure.

  The first three-way valve 12, the second three-way valve 15, and the third three-way valve 18 in the supply facility 1 of this embodiment may be configured by combining a plurality of normal gate valves.

DESCRIPTION OF SYMBOLS 1 ... Supply equipment, 10 ... High pressure gas container, 10a ... Container valve, 11 ... Pressure regulator, 12 ... First three-way valve, 13 ... First pressure gauge, 14 ... First filter, 15 ... Second three-way valve, 16 ... 1st gate valve, 17 ... 2nd pressure gauge, 18 ... 3rd three-way valve, 19 ... 2nd filter, 20 ... 2nd gate valve, 21 ... Flow meter, 22 ... 3rd gate valve, 23, 24 ... Exhaust Pipeline

Claims (5)

A gas supply method for supplying to a consumption facility after depressurizing a fluorine mixed gas filled in a container with high pressure through a depressurization means,
In the pipe from the container valve of the container to the pressure reducing means, a filling and sealing step of filling an inert gas at a pressure higher than the supply pressure to the consuming equipment and lower than the filling pressure of the container, A gas supply method for starting supply of the fluorine mixed gas to the consuming equipment in a state where the inert gas is sealed in the pipe after the filling and sealing step.   2. The gas supply method according to claim 1, wherein a purge process step of replacing the inside of the pipe with an inert gas is performed before the filling and sealing step.   The gas supply method according to claim 1 or 2, wherein the pressure of the inert gas in the filling and sealing step is 5 to 10 times the supply pressure.   The gas supply method according to any one of claims 1 to 3, wherein a sheet material of the decompression means is an ethylene trifluoride resin.   The gas supply method according to any one of claims 1 to 4, wherein the consumption facility is a semiconductor manufacturing apparatus.

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